Category: Technical FAQ

Technical FAQ: Campy shifting, cleat positioning


Have a question for Lennard? Please email us to be included in Technical FAQ.

Chain hop

Dear Lennard,
I have a Campy Record 11-speed EPS group on my Colnago C64. Aside from one issue, everything has been great with this combo of frame and components.

My problem is chain hop in the 34×13, 34×14, and 34×15 gear combinations. This occurs while under pressure and does NOT occur while in the big chainring (50-tooth) no matter what, if any, pressure on the big ring.

I do have your road bike maintenance book (4th edition) and consulted it. Nothing, including removing a chain link (I do have a 11×29 cassette) to go from 108 links to 106 has solved the problem.

Also, I have used three different models of 11-speed chains and the problem remains.
— Mark

Dear Mark,
I believe you have either worn out those cogs due to using them the most or your chain is being grabbed by the pickup teeth on the inboard side of your big chainring. If it’s the former, it only happens on the inner chainring under high load because there is a high amount of force wanting to yank the chain out of the worn teeth coupled with less derailleur tension holding the chain on a bit tighter. If it’s the latter, it doesn’t happen in lower gears because the chain line to the larger cogs doesn’t bring it so close to the 50T ring.

Check for cog wear with visual inspection (look for a hook shape to the teeth) or with a sprocket checker tool like the Rohloff HG-IG-Check tool. Unior and KMC make similar tools. You can also try putting a more worn chain on and see if the skipping goes away. If the cogs are worn, replace them.

If it is the chain hitting the large chainring, this is more likely to occur on bikes with a 34-50 front chainring combination because the 16-tooth size differential is so much more extreme than the 14-tooth jump from a 39T ring to a 53T. It happens more under heavy load, because the chain is so taut that it is less likely to just slide off the pickup teeth when it hits them. To avoid this exact occurrence, current Shimano Di2, for example, will no longer allow you to shift to the smallest two cogs when in the inner chainring. The solution for you is to not use those cross gears.
― Lennard

Downtube shifting

Dear Lennard,
I am building up a 650B Rando bike and want to use Campy 10-speed downtube shifters. I know Campy didn’t make 10-speed downtube shifters, but they made a limited amount of 9-speed downtube shifters. I have a set of 9s and was wondering if I bought the internals of 10-speed bar-end shifters, could I convert them to indexed 10?
— James

Dear James,
I have not tried that, but I think it is likely to work. I have mounted Campy frictional bar-end shifters on downtube shifter bosses and would not be surprised if indexed ones work that way as well.

The backing nut on Campy bar-end shifters is shaped like a downtube shifter boss, so those internals are likely to work on your frame’s shifter bosses. I don’t have one of those shifters around here anymore to look at, but if you were to look at illustration 5.44B on page 105 of the 5th Edition of “Zinn and the Art of Road Bike Maintenance” (this illustration appears in earlier editions as well, with a different number and on a different page), you can see that the backing nut resembles a downtube shifter boss.

You may find that it works better with the lever of the bar-end shifter rather than the 9-speed lever you have.
― Lennard

Cleat position

Dear Lennard,
Over the years, I’ve gotten the impression that moving the cleat toward the center of the shoe will obtain the best possible power transfer, but only Speedplay offers a special adaptor to allow more movement. Why do you think we don’t see more fore and aft cleat adjustability from manufacturers?
— Jeff

Dear Jeff,
It’s because not enough people demand it. I personally think that anyone with big feet ought to have their cleats further back than road cleats other than Speedplay allow.

I have three reasons for believing this:

1. Firstly, the calf muscles have to control the lever that is your foot from its hinge at the ankle to its attachment at the pedal. If you reduce the length of that lever, you reduce the energy wasted on your calf just keeping your foot stable.

2. Secondly, the bigger (heavier and stronger) the person, the harder they will push through the small interface between the pedal and the cleat. This larger force goes through the same tiny area of interface as a lightweight rider, but it puts way more stress on the metatarsals of the bigger, stronger, heavier person’s feet, leading to more “hot foot” pain if the cleat is located at the ball of the foot, and, in some cases, results in neuritis or neuroma between the joints of some of the metatarsals.

3. Thirdly, since you essentially shorten your leg length from the hip to the cleat by moving the cleat further back on the shoe, you can run a lower seat height with a more aft cleat. This results in lower aerodynamic drag and improved cornering due to a lower center of gravity, not to mention the possibility of a smaller frame size if you are in between sizes.

These are the reasons that I personally use Speedplay pedals; I have my cleats all the way back on the Speedplay cleat-extender base plates. You substitute these aluminum offset cleat-mounting plates for the standard plastic base plates; they allow you to position the cleat 2mm further forward than the standard plates or (and here’s their key feature) 14mm further rearward. Light Action, Zero and X Series only.

Mountain bike shoes already allow almost the same cleat position as Speedplay road pedals with the cleats all the way back on the cleat-extender base plates. Simply use the more rearward pair of holes in the shoe’s mounting plate and push the cleat all the way back.

I think people with big feet will immediately experience a sensation of being able to push harder on the pedals, if they have their cleats a centimeter and a half further back than most road shoes and pedals allow. I can’t speak for people with small feet, since I don’t have those. All customers of mine getting a full fitting who have feet larger than size 45 leave here with their cleats as far back as I can get them. After all, I doubt that King Arthur pulled the sword out of the stone with the ball of his foot on the stone; rather, to yank most powerfully while pushing hardest with his foot, I’ll bet he planted the underside of his longitudinal arch against that stone.

Incidentally, I have tried the extreme version of this: riding with my cleats right under the longitudinal arch of my foot (with my tibia directly in line with my cleat). So that I could experiment with this, Don Lamson made me a pair of custom, carbon-soled road shoes with two sets of three-hole cleat mounting inserts — one in the usual area under the ball of the foot, and the other in the middle of the longitudinal arch. While I found that this felt very powerful for climbing and it allowed me to lower my saddle by a full 3cm (!!), it felt too tippy for my comfort when standing out of the saddle. Also, some riders would have huge pedal-overlap issues with the front tire.
― Lennard

Read the full article at Technical FAQ: Campy shifting, cleat positioning on VeloNews.com.

Tech FAQ: Crank-spider tab thickness, tire specs, IT bands


Have a question for Lennard? Please email us to be included in Technical FAQ.

Drivetrain update

Dear Lennard,
I have an older road tandem with a 3×9 drivetrain that has sat idle for a long time. I would like to update the drivetrain to a 2×11 setup. The square taper arms will allow me to replace the BB to a shorter spindle to move the crank arm more inbound when the inner ring is removed to get the correct chain line. My question is regarding the spacing of the chainrings as they mount to the spider, or in other words the width of the tab that the rings mount to. Is there an issue with installing 11-speed rings on an older crankset? What is an acceptable distance that the chainrings should be spaced apart?
— Bart

Dear Bart,
I don’t know the brand of your cranks, but I would bet you are not going to have an issue.

As you may know, we machine cranks ourselves. I used to worry about tab thickness with increases in the number of rear cogs, as we started during the era of 9-speed cassettes and are now dealing with 11- and 12-speed cassettes. I measured the tab thickness of lots of cranks and was surprised to find that they don’t tend to vary between 9-speed, 10-speed, and 11-speed cranks. We settled on making the tabs on our cranks 3.55mm thick, and I know from personal experience that if your tabs are anywhere in the 3.55-3.65mm thickness range, you won’t have a problem with using it as a 2×11.
― Lennard

More on tire width and pressure

Dear Lennard,
I read the article about gravel tire width and pressure with great interest until I noticed the 140-pound weight of your test rider. [Ed. note: this was in the VeloNews print magazine; here is an earlier article from the magazine on pressure alone.] I’m 100 pounds heavier than that and wonder what you think would happen to your results with someone my size?
— Lee

Dear Lee,
The tire widths that work best on gravel roads would go up with your greater weight. And the optimal air pressures with those tires that worked best would also go up. Without doing that specific testing, I cannot quantify it any further.
― Lennard

Feedback on nagging IT band pain

Dear Lennard,
I just read the question from the guy with IT band issues. I had a severe issue with this decades ago and what fixed it, permanently, was 1 minute of a stretch called the “pretzel” every night. Seriously, in a week the condition was resolved. You lie on your back, cross your legs with knees bent, and pull your knee with both hands toward your sternum, same on both sides. Might want to suggest this to everyone. Free and it worked for me.
— Jonathan

Dear Lennard,
I suffered from debilitating ITBS for years and did innumerable sessions of stretching, painful A.R.T. [Active Release Therapy], massage, and enough rest to drive me crazy. But when a friend put me onto the research of Dr. Reed Ferber, director of the Running Injury Clinic in Calgary, Alberta, I quickly solved the issue using a very simple protocol. With relatively minimal maintenance, I have been ITB pain-free for the past half-decade.

The bottom line is hip stability. Cyclists and runners generally have terrible hip stability because of the biomechanics, and primary movements, of both sports. Now I do a series of side-to-side squats/lunges in a plyometric style of movement, and when starting out it’s brutal because of weak glutes. But it works. Some of Dr. Ferber’s research and protocol is published in this article.
— Jamie

Dear Lennard,
I was having a lot of trouble with really tight IT bands, and I found this stretch on YouTube. For me, this literally worked after 30 seconds or so, and after doing the stretch a few times a week for a couple of months I haven’t had another problem.

I also tried bands and rollers, but I don’t need to do them anymore when I use this stretch.
— Rob

Dear Lennard,
Years ago I started to have knee pain and, after some false starts, I finally narrowed it down to IT Band tension. The first two stretches in this video are the
 ones I use. They can be done anywhere — I’ve stopped in the middle of a ride and leaned against a telephone pole instead of the wall used in the video. In my case, knee pain relief is almost instant after a few rounds of stretching each side.
— Doug

Read the full article at Tech FAQ: Crank-spider tab thickness, tire specs, IT bands on VeloNews.com.

Tech FAQ: Cogs, thru-axles, and nagging injuries


Have a question for Lennard? Please email us to be included in Technical FAQ.

Wide-range cassettes

Dear Lennard,
I greatly enjoyed your recent writings on adapting to wide-range cassettes. I ride a Shimano 11-speed road hub but I’m having trouble finding 11-speed cassettes in the 11-40 or 11-42 range. Can you suggest any candidates/sources?
— Mike

Dear Mike,
A Shimano XT CS-M8000 11-speed 11-42t or 11-40t cassette is the option we most often use. If you want lighter weight with some titanium cogs, you can get an XTR CS-M9001 11-40t cassette. There is also an SLX CS-M7000-11 11-42t or 11-40t cassette in 11-speed. All of those work on road-wheel 11-speed Shimano compatible freehub bodies.
― Lennard

Thru-axle conversion

Dear Lennard,
This may be an off-the-wall question, but is there any way to convert a QR frame to use thru-axles? I know you can get those inserts to convert the other way but my skewers on my e-MTB keep coming loose. I suppose I can change the front fork but what about the rear?

BTW, I just started riding my Haibike hard-tail MTB and it has given me, at age 78, a totally new enjoyment of trail and road riding. And my riding buddies don’t thumb their noses at me — they want one too!
— Ted

Dear Ted,
There is not a simple, inexpensive way to reconfigure a frame to accept a thru-axle rear wheel. If it’s a metal bike, you could, in theory, have a framebuilder weld new rear dropouts on it to accept thru-axles, but by the time you repaint it and reassemble the components, as well as get a new fork and new wheels if yours cannot be reconfigured, you’re talking a big chunk of change. And I suppose Calfee Design or another carbon repair place could conceivably replace both dropouts on a carbon frame, but, again, it would be so expensive that it would be pushing the limits of what makes sense.

I’m glad you’re loving that e-bike!
― Lennard

Hamstring and IT band issues

Dear Lennard,
I have the same exact hamstring problem you have described in the last few tech columns. I’ve been going to therapy and massage and even though they haven’t made things worse, they also haven’t made them much better. Things feel the same.

I’ve also had an IT band problem, which is nothing new to me. I first had a flare-up at around age 18, then later on at 32 or so and now I’ve had another one at age 50. The latest one started in the spring of 2017 and it’s still there.

Because of these two injuries, I haven’t been able to ride any significant amount. It’s actually been months since I last rode.

I have tried many things but I’m curious about what you have found works for both problems. I know you last mentioned doing eccentric exercises for the hamstring and I would like to know how much that has helped and if you have found out anything else since you last discussed this. And if you have found any magic potion for the IT problem, I would also like to hear about that.

Looking forward to your input!
— Manuel

Dear Manuel,
I too have not had a complete cure by any means. Like you, I would also say that therapy and massage haven’t done much to relieve the problem. It is improving when looked at from the perspective of many months, but the progress is so glacial that I cannot notice an improvement week to week or even over one month.

As for IT bands, I do have something to say about that. I realize now that mine has not been bothering me for so long that I didn’t even mention it in this post about chronic injuries.

Regarding my hamstring injury, my pain is no longer focused on my left sitbone like it was. And I no longer have any pain while riding a bike, even when bouncing around on a rough cyclocross course or jumping off for barriers (the first foot strike when jumping off had been excruciating, and the jump off of the left foot back onto the saddle hurt a lot too; now those things no longer bother me). It mostly no longer bothers me doing squats like it used to, and I can ski (alpine and Nordic) pain-free. While it can hurt on my left sitbone from time to time, my major symptom is now soreness over a bigger area of my entire left butt cheek, and only after sitting (in a car or bus seat or chair) for at least a half hour (driving is especially painful).

I had a PRP injection and then lots of physical therapy with dry needling and electrical stim (with the electrodes hooked up to the acupuncture needles), first on the hamstring and then on the piriformis, gluteus medius, and low back muscles. I then switched to doing “counterstrain” physical therapy. I also have been doing lots of hamstring and piriformis strengthening exercises and stretches, including the hamstring curls (which I do on a 75cm Swiss ball). I have also been doing “nerve glide” exercises with my left leg to free up my sciatic nerve; it seemed to have adhesions restricting its freedom. I stopped sitting at my desk; I got a standing desk and do all of my desk work standing — including writing this column. I also do my sitting meditation lying down now.

I went back for another ultrasound three months after the PRP, and it showed that substantial healing has happened and that the nerve was stuck closer to my sitbone than it ought to be.

As for the IT band, have you done anything with your shoes or insoles? In my case, my IT bands are super sensitive to having my foot tipped to the outside (some shoes are made with a thicker sole on the medial side than on the lateral side, and they put me in excruciating pain after one ride). Tipping the foot to the outside puts additional tension on the IT band; try it yourself to see what I mean. When mine flares up, after I rest it until it no longer hurts when not on the bike, I wedge (cant) my insoles dramatically under the lateral side to tip my foot in toward the medial side (I cut the wedges out of old insoles). Over time, I gradually remove the wedges as my symptoms disappear. While I can ride without additional cants on my right foot, I have a thin wedge always under the forefoot of my orthotics in all of my cycling shoes, and I also use custom orthotics in all of my cycling shoes and ski boots, both alpine and Nordic.

I stretch my IT bands nightly. I also roll on a foam roller on the sides of my thighs to maintain as much suppleness as I can in my IT bands. There have been times when my IT band problems were so great I thought I might need surgery or stop riding. But with this regimen, I have not had a significant problem with them in probably 15 years.
― Lennard

Read the full article at Tech FAQ: Cogs, thru-axles, and nagging injuries on VeloNews.com.

Technical FAQ: Derailleurs, brakes, and frame fatigue


Have a question for Lennard? Please email us to be included in Technical FAQ.

Front derailleur adjustment

Dear Lennard,
I keep having to readjust my Ultegra Di2 front derailleur. How do I get it to hold its adjustment?
— George

Dear George,
The limit screws on some Ultegra Di2 front derailleurs from a few years ago tend to unscrew over time. We have had success with just putting Loctite on the threads of both limit screws. It completely made the difference on my personal Ultegra Di2 bike.
― Lennard

Brake lifespan

Dear Lennard,
I have been following with interest your recent conversations about the fatigue life of aluminum and its inevitable failure at some point due to the material’s characteristics. This made me wonder about caliper brakes. In all my experience of riding and repairing bikes over 30 years or more, I have never encountered or heard of a broken caliper arm. My first thoughts were that maybe I’d been lucky, but could this apparent strength be due to them being forged, or is it the amount of material and nature of the stresses put on them that makes them so resilient?

In the past, I had heard stories of CNC’d components failing due to imperfections in the billet they were machined from and the proper way of manufacture was to rough forge the shape and finish with CNC. Obviously, this would not be applicable to frame tubes, so are there different rules for the same material having been treated differently?
— Peter

Dear Peter,
I forwarded your question to Craig Edwards, the designer of the eeBrake and many other bicycle components. Here is his answer:

“Forces that brakes encounter in use are limited by hand strength, lever configuration, cable stretch, and coefficients of friction at the pad/rim as well as the tire/ground. All of these effectively limit brake stresses to be relatively low.

This, combined with the number of times a brake receives the maximum stress the “system” can deliver, is relatively few, conservatively speaking: 10 years use x 1 all out panic stop 3 times per ride (to max. stress) x ride 365 days a year = 11,000 cycles). Sub-maximal braking creates very low stress and has little effect on fatigue. Realistically, I would say if you had one panic stop a week, you would probably find a new sport within a year, so getting to 11,000 maximum stress cycles is hard to do.
— Craig
eecycleworks.com

More on widening gear range

Dear Lennard,
I climb a lot of mountains and ride off road, so I need a bailout gear.  I recently set up this configuration. It shifts well — unlike my old bike!

I would have tried a subcompact crank but worried about front derailleur clearance.

Cervelo C3
— Shimano Ultegra ST-RS685 Disc Brake Dual Control Lever 2×11
— Praxis Zayante Carbon 165mm 48/32 crankset
— Ultegra 11sp Direct Mount FD-R8000-F
— Shimano XT M8000 Shadow RD+ Long Cage 11sp RD-M8000-SGS
— Wolf Tooth Tanpan Shimano 11 INLINE
— Shimano XT M8000 11 speed 11-42
— Norman

Dear Lennard,
We (Wolf Tooth) actually have a RoadLink optimized around road derailleur geometry and more moderately sized cassettes. The RoadLink DM would be Kristian’s best bet for an R8000 with 10-42 (SRAM), 11-40 (XTR), or 11-42 cassettes. A GoatLink wouldn’t improve things nearly as much (the GL10 is better than the GL11, though).
— Marc Basiliere
Lindarets, LLC
lindarets.com

More on fatigue life of carbon frames

Here are some more answers from engineers in the bike industry regarding this topic.

From Felt Bicycles:
Like aluminum, carbon fiber will always start decreasing in strength as the number of stress cycles continue. Loss in strength over time is measurable as loss in stiffness. But we can work with this and achieve light bikes that last a long time.

We used to have problems with aluminum frames developing fatigue cracks at the weld joints, but when we went to butted tubes, the frames became lighter and the fatigue problems disappeared. A butted tube didn’t move all of the stress to the weld joints the way stiffer, straight-gauge ones did, and that’s why it improved the fatigue life of aluminum frames.

Similarly, different carbon fibers and orientations will make a big difference in fatigue life. If there is not a “balanced laminate” around the plies — for instance, the carbon plies are too stiff on the outside relative to those inside, stresses will break down the layers that are stiffer first.

If you have the same mold and the same carbon but have an unbalanced layup or voids or imperfections in the laminate, then fatigue life will be reduced. Since carbon does not have standard, always exactly repeatable mechanical characteristics, you can’t make a blanket statement about fatigue life like you can with metal frames. Carbon is not like a metal alloy tube that has standard mechanical properties for that alloy and thus can have a predictable lifetime. This is why you don’t have as much carbon in aerospace applications as you might expect (given its light weight), because you can’t make a 100 percent guarantee of how the tube will perform like you can with a metal tube.

Even though the strength of a carbon frame starts decreasing as soon as it starts going through stress cycles, 100,000 stress cycles on our frames with a layup balance only result in a 1-2 percent loss in stiffness.

A premium frame from a reputable manufacturer will have a balanced layup and will be well-tested, whereas a counterfeit frame won’t. Multiple thin plies is better for fatigue life than the same amount of carbon in fewer, thicker layers.

While it is technically correct that carbon has no fatigue limit, it is practically correct to say that it behaves like a steel or titanium frame with a fatigue limit because the carbon frame is so overbuilt. You can keep running the fatigue test almost indefinitely because you will never approach a stress level in regular use that starts to break it down significantly.

I did a little digging after our conversation and found a nice article that summarizes the same ideas we spoke about.
— Jeff Soucek
Felt Bicycles Director of Research and Development

From Kappius Components and Broken Carbon (repair service):
Here is what I have to say about fatigue on carbon fiber composites. Unfortunately, it’s not as cut and dry as we wish it would be with a composite frame. In general, the fatigue strength of composites is very high, but you are right, they do not exhibit a fatigue limit like steel alloys do. But the counterpoint is that their cycles to failure is so high that ultimately their time to failure exceeds any standard lifetime of a frame on the market. I could easily see a well manufactured and maintained frame last 100 years.


The assumptions in this model are the issue though. There are a huge number of variables on the manufacturing side, including but not limited to the volume fraction of fibers, voids, inclusions, misoriented layup, curing rate mistakes, and poor compaction. Failure could also be associated with bonded-in components that fail at the interface between the composite and insert. Those in combination of potential issues on the consumer side with impact damage, high stress events (crash for example) and UV degradation, the lifetime of carbon fiber composite frames can be significantly reduced.


Ultimately, with proper care and a frame from a reputable manufacturer with a good warranty policy (most have lifetime warranties for the original owner now), a composite frame should last a very long amount of time.
— Brady Kappius
President of Kappius Components
Owner of Broken Carbon repair service

From Specialized:
Generally speaking, carbon/epoxy composites are not practically affected by fatigue testing. Composites, if designed and manufactured properly, should have a near-infinite fatigue life. This is true, assuming that the product is kept in good condition without impact damage. If damage is introduced into a higher-stressed area on a frame, fork, or component, then fatigue can become an issue, depending on the damage and location.

Bottom line, we fatigue test all our composites. Generally, impact and ultimate force testing are higher priorities at Specialized than fatigue testing but when you get cocky, you are likely to be on the wrong side of safety.
— Mark Schroeder
Specialized Bicycle Engineering Director

From CarboFibretec:
To answer your question concerning carbon fiber fatigue.  Compared to metals, this topic is much more complex with composite materials and not yet as well-researched. The fatigue of composites has much more influence than only the type of material and the load. It depends on the materials of fiber and resin, if the fibers are unidirectional, a woven fabric, braided, filament wound … and also the process parameters while curing. Due to its anisotropic properties (different stiffness and strength in different directions) it is also not possible to determine only one fatigue strength.

But in short conclusion, the fatigue strength of carbon fiber is much better than fatigue of aluminum and can also be better than metals like steel, depending on the use case. 
One example: if you have a part with loads just in fiber direction, the fatigue strength will be almost at the level of the static strength.
— Michael Hübner
Head of R&D – Sporting Goods
CarboFibretec GmbH

From a bike testing engineer:
As a design concern, fatigue is less of a factor for carbon. Certainly, everything will break eventually. There are notable exceptions for fatigue in carbon frames, mostly involved with bonding at lugs aluminum joints, etc., which is why they are still tested in fatigue to make sure the attachments are sound and that layups have not pushed the limits of the material or bonding.
— Mark Rhomberg
Test Engineer, formerly for Schwinn, GT, SRAM, and Bike Testing, Inc.

From a former Kestrel Bicycles engineer:
As is usually the case with composites, it is really difficult to generalize because of the virtually unlimited combinations of matrix materials, fibers, fiber orientations, manufacturing processes, and environments.

But the short answer is yes, composites are subject to fatigue.

If you ran a fatigue test of neat resin you would find its strength degrades under cyclic fatigue loading much like aluminum does. Fibers behave in more or less the same way.

What’s interesting is when you create a multi-ply composite laminate. Failure in one layer (either fiber or matrix) will not necessarily propagate through the entire structure since the adjacent ply is likely oriented in a different direction. Of course, aluminum, once a crack develops, will ultimately fail.

Composite materials are also extremely strong — so even though they do not have an “endurance limit,” they are generally operating at a relatively low level of stress. Toray T700 (carbon) is the workhorse of the industry and has a tensile strength of 4900 MPa. Given the log scale of the S-N curve, this can put the failure point out many lifetimes or hundreds of lifetimes.

I can’t say I have ever seen a classic fatigue failure of a composite bicycle frame or component. Rather, I have seen failures that fall into two buckets; impact damage and manufacturing defect.

After being acquired by Schwinn, Kestrel sent a 4000 road bike to be tested on Schwinn’s fatigue rig. After exceeding several lifetimes of cyclic fatigue loading with no failure in sight, they gave up and shut it down.

Another interesting tidbit: there is speculation that one of the main economic drivers in support of the 787 composite fuselage will be reduced maintenance costs. Aircraft go through a periodic heavy maintenance check where the airframe is inspected for corrosion and fatigue and repaired. It is almost a certainty that fatigue cracks will be discovered in an aluminum airframe during this maintenance check. The expectation is that the 787 will show little or no degradation from fatigue loading (and corrosion), which may compel the FAA to extend this very costly maintenance interval.

This is an area of research that could keep PhD candidates busy for decades.
— Kevin Kenney, formerly with Kestrel Bicycles

Read the full article at Technical FAQ: Derailleurs, brakes, and frame fatigue on VeloNews.com.

Technical FAQ: Getting lower gears


Have a question for Lennard? Please email us to be included in Technical FAQ.

Shadow derailleurs

Dear Lennard,
If I want to run some 6800 mechanical hydro shifters with an 11×42 cassette, what are my options? A simple question is lots of different avenues to answer. If I had Di2, this would be easy, but that isn’t happening. Would a combination of the new R8000 shadow RD work with Wolf Tooth’s GoatLink?
— Kristian

Dear Kristian,
I don’t have personal experience using that cassette with a Shadow rear derailleur, but I have closely related experience with non-Shadow Ultegra rear derailleurs that I think sheds sufficient light to answer your question with a high degree of certainty. The short answer is that I think that the RD-R8000-GS Shadow rear derailleur will be able to handle that cassette, and a RoadLink or GoatLink 11 may be required.

I had this Ultegra Di2 GS rear derailleur on one of my bikes for many years, and I used it with an 11-36 without any adaptations other than b-screw adjustments. It worked great, despite the fact that it is rated only to 32T maximum cog size. I am doing the same with this non-Di2 model on another bike. I also used these same derailleurs on 11-40 cassettes with the Wolf Tooth RoadLink, again with good shifting and no bumping on the largest cog. The length of the derailleur hanger differs on the two bikes, and the one with the longer hanger almost ran noiselessly on the 11-40 cassette without the RoadLink, so I’m sure some bikes would work with that combination with no further adaptation.

Shadow road rear derailleurs have a capacity of two more teeth than their non-Shadow siblings. So, the RD-R8000-GS Shadow rear derailleur is rated to a maximum cog of 34T, where the 6800 was rated to 32T max. Given my experience with the 6800 and 6870 derailleurs rated to 32T handling an 11-40, I’m confident that the R8000-GS RD would work with the 11-42 with a RoadLink or with a GoatLink 11.
― Lennard

Gearing for Colombia

Dear Lennard,
I am planning a trip to Colombia partly to do the famed Alto de Tetras climb, which has over 13,000 feet of climbing in 50 miles. I am a bit concerned about doing this, particularly at altitude and with my winter fitness level.

Low gearing will help. Do you think I can run SRAM eTap Wifli 11-speed with my 46-30 chainrings (Compass). If you do, then I will have a 30-32 low gear.
— David

Dear David,
The mid-cage (WiFli) Red eTap rear derailleur will indeed handle an 11-32 cassette (and possibly larger if you want to experiment).

As for the eTap front derailleur, I think you’ll run into similar issues with any road front derailleur on such small chainrings. The curvature of the front derailleur cage is optimized for a 50-53T big chainring. If you use smaller chainrings, the problem is that the leading end of the cage is further away than optimum when the tail of the cage is just barely clearing the chainring. The leading edges of the front derailleur being close to the chainring is crucial for quick, accurate shifting.

If you have gotten away with that 30-46 combo with a road front derailleur, then you know the issue. I suspect it will work well enough to get you through your Colombia trip, but it certainly will not shift as snappily or as flawlessly without chain drop as if you were running a 39-53 or 34-50. You will probably need to experiment with a slight twist to the front derailleur to avoid throwing the chain while still getting acceptable shifting.
― Lennard

Feedback on last week’s column

Dear Lennard,
Just to set the record straight on Universal brakes, alloy racing side-pulls were offered from the late 1930s, were prevalent on Italian bikes until the early sixties, and were very much equivalent to any brake from Lam or Weinmann in the era. In 1961, Universal introduced model 61, the center-pull model to respond to the Mafac Racer, the dominant brake in the racing market until Campagnolo created their iconic brake in late 1968. The Universal mod 68 side-pull (not a coincidence) was their last high-volume offering, indeed lacking stiffness and refined finishing compared to its Italian competitor. Readers owning classic bikes from the 1950s or 1960s will want to know.
— Denis

Dear Lennard,
Any of the common frame materials can be used to construct a frame that will last more than a human lifetime of riding by an arbitrarily heavy and strong rider over an arbitrary terrain and road surface. Such a “lifetime” frame will, however, be heavier than a frame of the same material built to last, say, 10 years for the same rider and conditions. A frame built to last five years will be still lighter. The lighter frames with potentially limited but “long enough” lifespans will be more attractive to “most” prospective buyers.

I’ve raced since the early 1970s, worked in multiple shops, and earned a BS in mechanical engineering. I’ve owned and/or observed many steel and titanium frames that have suffered fatigue failures. While a steel or titanium frame may well be operating below the material’s endurance limit while “JRA,” it’s probably well above the limit when the rider hits a pothole during an uphill sprint or brakes hard on a steep descent on a washboard road surface.



On a different topic, Universal made two different models of side-pull brakes that used their characteristic link-arm style of quick-release mechanism. The Type 51 had thin, gracefully curving arms and were generally of quite long reach. The later Super 68 brakes had arms shaped much like the Weinman 500. The 51 was quite flexy and the long reach meant that leverage and braking force was minimal. The Super 68s weren’t bad brakes, and while they obviously weren’t as good as the Campagnolo brakes, they also didn’t cost anywhere near the Campy’s outrageous $60 price (that was for the set including calipers, levers, cables and casing, and top-tube clips).
— Harry

Dear Lennard,
The discussion of frame fatigue is very interesting. I stumbled on this Sheldon Brown page  demonstrating a real-life fatigue test. The result seems to indicate that the real fatigue limits are mostly unrelated to material but design alone.
— Bo

Read the full article at Technical FAQ: Getting lower gears on VeloNews.com.

Tech FAQ: Universal brakes and frame fatigue


Side-pull vs. center-pull brakes

Dear Lennard,
Recently, a friend sent me post cards from the cycling shrine at Madonna del Ghisallo, Italy. One pictures the bicycle ridden by Gianni Motta in the 1966 Giro d’Italia. The bike has side-pull brakes. The cable tension screw on the levers looks like the system used on Universal brakes. But I recall that Universal was only making center-pull brakes, which were all the rage until Campagnolo came out with their side-pull in 1968. I am the original owner of a 1965 Masi Special that has Universal center-pull brakes. It is strange; when I started racing in the late 1950s, side-pull brakes were the only thing around. Then the fad went to center-pull (and recessed headsets, too) and back again to side pull. Do you have any idea what brakes may be on the Motta bicycle?
— Michael

Dear Michael,
I’ll bet those are Universal, which did make side-pull brakes and were the low-cost alternative to Campy Nuovo Record side-pulls at the end of the 1960s. They were light weight and had very thin, flexy arms; they offered very low braking power compared to what we are now used to (or to Campy brakes of the 1970s). My roommate in college in 1977 had some Universal side-pull brakes on his otherwise full-Campy Cinelli that he had bought used, so it was probably late 1960s vintage.
― Lennard

Regarding last week’s column

Dear Lennard,

In regards to your recent Technical FAQ about fatigue life of aluminum, this photo might give your readers pause and send them off inspecting their aluminum frames immediately. I found this while washing the bike. I don’t know how long it was like this, and we had just finished a week-long trip along Lakes Erie and Ontario, riding every day. I shudder every time I think of it.

Having taken several materials classes in my engineering school days, I have always understood the fatigue issues with aluminum, and I always did look the bike over when I washed it, but I should have been even more diligent. In this case, luck won out.

The bicycle is (was) a 2004 Burley tandem, with about 15,000 miles on it.

A related question — what are the fatigue characteristics of carbon fiber structures? My only experience with composite materials is reinforced concrete.
— Richard

Dear Richard,
While carbon fiber composites can have very high strength-to-weight ratios and high elastic modulus (hence, high stiffness), they do not have a definable fatigue limit or endurance limit. Thus, fatigue failure is, in theory, possible with carbon parts, but since the strength of the part can be so high, this can keep the stresses still well below the S-N curve for a carbon part.

I’ll let the pioneer in carbon bicycle frames, Craig Calfee, answer your question more completely.
― Lennard

Hi Lennard,
Composites are very different when it comes to fatigue failure. Theoretically, because the strength of carbon fiber is so high, designed stresses would never approach the yield strength, (which is almost the same as the ultimate tensile strength because carbon fiber is so brittle). A well-designed (and well-built) carbon fiber component will never fail under normal loading. But a stress concentration can be built into a poorly made component, rendering that area prone to a fatigue crack. The failure mechanism starts with the epoxy matrix, which starts microcracking in the high-stress area. That starts rendering the epoxy ineffective as a matrix for the carbon fiber and soon results in the fiber starting to break. This is when the fracture starts to be visible on the surface. Note that the vast majority of composites failures make their appearance on the surface because that is where the maximum stress is located when caused by a stress riser. Once the fiber starts to break, the component will soon fail catastrophically, not giving nearly as much warning as metals do.

If a component is designed for lowest possible weight without margin for typical abuse, minor manufacturing errors, or subtle changes to the design, a very small gouge will become a stress riser that will lead to a failure. This is why we stay quite busy with our carbon repair service. A component designed with a margin for this type of real-world experience will last a lot longer because a small, unnoticed gouge will not progress into a full-blown crack.
— Craig Calfee
Founder and President, Calfee Design

Dear Lennard,
I was quite put off by the answer you gave to Gary when he asked about whether having ridden 24,000 miles on his frame so far should worry him that it won’t last through some touring.

The answer you gave seemed to be something like, “well, aluminum will eventually fail. I don’t know when it might happen, so you should get a new frame now.” 

What frame of reference are you using for that? How much stress is a frame actually experiencing in different situations? And how many cycles might occur per, say, 1,000 miles of riding? Personally, I don’t know what rider weights, uses, and impacts can cause a stress of, 10ksi, or 20, or 50. Do you? 

What if everything but a hard crash causes — Travis

Dear Travis,
Your reading of my answer is different from mine. Gary is planning an extended loaded tour on a bike that he had ridden 24,000 miles on, some of it loaded touring, and he is concerned about whether his bike will make it through. I was answering from the perspective that he may be better off getting a new frame than having that worry in the back of his head detracting from the awesome trip he is embarking on. I am sure he doesn’t want to find a crack on his tour like the first reader in today’s column.

Since I know nothing about how heavy or strong Gary is, what kind of road surfaces and terrain he rides on, how heavily his packs are loaded when he tours, what his riding style is like, and what tubes his frame is made out of, I cannot begin to approximate the magnitude of the stresses his bike has been subjected to in absolute terms. I can tell you that in terms of fatigue testing, each pedal stroke is considered a stress cycle, so that is quantifiable if we were to know Gary’s average cadence over all of those miles.

I can give you an answer to your last question, since any bike shop can tell you that they have seen plenty of aluminum frames that have cracked from fatigue within a year or two. Consequently, we know that those riders are producing stress cycles far beyond 1ksi (i.e., 1,000psi).

Consider the following facts:

1. The ultimate strength (tensile strength) of high-quality aluminum tubes used in bike frames is on the order of 60ksi.

2. Some strong riders manage to break frames made out of such tubes within a few years of normal use.

3. Even though aluminum has no fatigue limit, its S-N curve is high above the horizontal axis (indicating stresses that are a high percentage of ultimate strength) for a huge number of cycles (the horizontal scale — number of stress cycles — is logarithmic on an S-N curve).

From these facts, we can certainly say that those tubes, in order to break within a few years of normal riding, are experiencing stresses on the order of at least 30ksi. Add loaded packs to the same bike with the same rider and the stresses go up and the frame’s life is even shorter.

Since any bike survives the vast majority of rides that its rider embarks on, and Gary’s has survived 24,000 miles, chances are that his will survive this trip, too. But he asked me if the number of miles on the frame is a practical concern. Since it is aluminum, which has no fatigue limit, every single pedal stroke, and hence every mile traveled, is indeed a practical concern, because every one of them shortens its life. I still have no idea how long that life will be, given the dearth of data about him and his bike that I had to work with, and I said that.

My point is that the unpredictability of it lasting the trip or not increases when using a material like aluminum that has no fatigue limit. If he instead had a steel or titanium bike (which have fatigue limits), and we were able to measure that the stresses he is providing on its steel or titanium tubes were below 30ksi when on his loaded tour, I could guarantee him that a well-made frame without notches, dents, or corrosion would not fail from fatigue during his trip. That’s because titanium tubing used in bike frames has tensile strength on the order of 100ksi, and steel tubes in quality bike frames have tensile strengths of 125-200ksi, so 30ksi is well below the fatigue limit (typically around half of tensile strength) of those tubes.
― Lennard

Read the full article at Tech FAQ: Universal brakes and frame fatigue on VeloNews.com.

Technical FAQ: Aluminum frame, crankarm fatigue


Have a question for Lennard? Please email us to be included in Technical FAQ.

Aluminum frame fatigue

Dear Lennard,

I have a high-quality aluminum bicycle frame that has been through 24,000 miles of commuting and touring. The frame has had proper maintenance, has never been crashed, and by all outward appearances is in very good condition. I’m planning a lengthy loaded tour on this frame. Since aluminum is subject to metal fatigue, is the number of miles on the frame a practical concern with respect to structural integrity?
— Gary

Dear Gary,
Yes, the number of miles is a concern, because aluminum has no “fatigue limit” (a.k.a. “endurance limit”). Let me explain.

While not every engineer uses the same terminology, for the purposes of this article, a material’s fatigue limit or endurance limit is the highest stress that the material can withstand for an infinite number of cycles without breaking. When it comes to metals used in bicycle frames, only steel and titanium have a fatigue limit. This means that if the stresses applied are below a certain percentage of a steel or titanium tube’s ultimate strength (or “tensile strength” — the stress required to break it with a single application of that stress) — the percentage at the fatigue or endurance limit, then no number of stress cycles will result in failure.

This fatigue or endurance limit can be seen on an “S-N curve” — a graph of magnitude of applied stress on the vertical axis vs. the number of stress cycles on the horizontal axis. The S-N curve for steel and titanium sweeps down from the upper left toward the right until it hits the fatigue or endurance limit (typically about half of its tensile strength), after which it forms a horizontal line continuing indefinitely to the right.

Aluminum does not have a distinct fatigue or endurance limit, so its S-N graph curves down from the upper left to the right and continues to curve down lower and lower toward the lower right corner of the graph. This illustrates that it will eventually fail even from low stress applications, given enough of them.

I of course have no way of predicting when your bike frame will fail; I only know that, since it is aluminum, it will eventually fail from fatigue, if it is ridden enough miles. It seems to me that the downside of a frame failure on your lengthy loaded tour would be high — it would cause you considerable additional hardship. You do have a lot of miles on that frame, and, given that a lot of those are loaded miles (putting you higher on the S-N curve, resulting in a lower number of stress cycles to failure), it might be time to let go of that bike and get a new one for your tour.

If you had a steel or titanium frame, I could make no such prediction of certain fatigue failure. That’s because, if the frame’s designer chooses steel or titanium tubes whose tensile strength and dimensions (wall thickness, diameter, and shape) are such that the stresses seen while riding will never exceed — say, 40 percent of its tensile strength in its heat-affected (i.e., weld) zones — then the frame will last indefinitely in the absence of a crash. Of course, notches or dents or poor welds (or, in the case of steel, rust) will lower that limit (as well as lower the tensile strength) and cause fatigue failure to occur at a lower stress or lower number of cycles.

I suspect you asked the question because you had some trepidation about taking that bike on your tour. While it may survive the tour, I think the probability of it not surviving it is high enough that it would be worth the peace of mind of instead riding a bike that gave you more confidence in its longevity.
― Lennard

Broken crankarm

Dear Lennard,
I just had an Ultegra 6800 50×34 crankarm fail at the glue joint after 3 years, resulting in a tearing of the aluminum spider (see photo here). Not shown is the glued seam that has split apart. I use a 20mm pedal extender from Knee Savers.

Is this a faulty crankset, or are hollow crankarms just not strong enough to handle the additional load brought about by having the foot further from the attachment point on the arm? I can’t find anything about this on the web. Shimano sells the PD-9100 pedal that allows 8mm of play side to side, so clearly they permit some movement of weight away from the pedal attachment point.

Do you think that the 8000 series crankset, with its much beefier arm at the spider end, is a better choice? If I need to use a crankset with solid arms, what do you recommend for a Di2 setup?

I’m asking you this question because you sell bicycles for “oversized” people, and you must have run into this problem in some way. If not pedal extenders, then heavier people. I weigh 175 pounds and stand occasionally while pedaling. I’m not a masher — other than when standing, I pedal at 90 rpm and am fairly light on the pedals.
— Chuck

Dear Chuck,
You’re right; I certainly have run into this issue. Yes, the extra leverage of standing on pedals with a 20mm longer spindle multiplies the stress at the pedal eye of the crank compared to the same pedaling force with standard-length spindles. And many times, bike fitters have prescribed extra-long pedal spindles for big customers of ours in order to get their knees closer to vertically aligned above their feet. Since these customers are also heavy and very strong, crank longevity is a definite concern.

We often build the bikes for tall people with a high bottom bracket coupled with extra-long cranks so that their crank length is a more standard proportion of their leg length than, say, a 175mm or 180mm crank would be; thus, we are often not using Shimano cranks on an otherwise Shimano drivetrain. The extra-long cranks we make in Boulder we have tested in a lab to ensure that they endure far beyond the crank-fatigue standard required by the European Union. And when we sell extra-long cranks made by Asian manufacturers, we request test data, using the same ISO4210 fatigue-test protocol, from the crank manufacturer. I have attached an illustration and description of the ISO4210 crank fatigue test (formerly called EN14781); a video of the test can be seen at the bottom of this page.

I would expect you to be able to get a lot more than three years on any crankset, including that one, with your 175 pounds, regardless of the 20mm longer spindles. As described in my prior answer, aluminum is subject to fatigue. Of course, if the glue joint failed first, that is a completely different issue from straight aluminum fatigue, since the crank would no longer have the structural integrity granted by its clamshell construction. If that were the case, that would be cause for a warranty appeal, but this is out of the two-year warranty. In any case, the stresses you are applying on the S-N curve that I described above are higher due to those longer spindles, which results in fewer stress cycles to the point of failure.

I can’t answer whether a Shimano 8000 series crankset will last any longer, since there are so many variables involved, and I’ve never seen fatigue-test data on either. Shot-peening, for instance, which increases fatigue life, could have been done on one crank and not the other, and/or the aluminum alloy could be different, and I have no idea about the wall thicknesses in each or how the extra crank width influences its durability. While solid arms in the same alloy and shape as your Ultegra cranks would almost certainly last longer than yours, solid arms in a different crank design do not necessarily guarantee more longevity than a well-made hollow one.

As for whether non-Shimano cranks will work on your Di2 setup, I also have lots of experience with this, since we sell a lot of Di2 bikes, and they usually don’t have Shimano cranks on them (because the cranks are 190mm-215mm long). Assuming your Di2 setup is 11-speed, you of course ought to get an 11-speed crank. After that, the most important thing is to get the stiffest chainrings you can, and there are lots out there that work just fine with Di2.
― Lennard

Feedback on last week’s column

Dear Lennard,
I wanted to chime in on Joseph’s question about fitting an 11-speed cassette on a 10-speed hub. I was in a similar situation. Almost all of my wheels have 10-speed freehubs, but I now have an 11-speed drivetrain.

I purchased a Shimano 105 5800, 11-28 cassette and removed the third cog (the 13T) because the 11T and 12T nest together. Besides adjusting the derailleur limits, as you mentioned, you also need a slightly thicker spacer behind the cassette to make this work. Without the spacer, the cassette can’t be tightened enough.

Other than that, the setup has worked well for me!
— Aaron

Dear Lennard,
I’ve done that by removing the 11t cog and keeping the 12t. You’ll need a lockring for 12t cassettes.
— Gabriel

Dear Lennard,
The new Shimano R7000 11/34 cassette comes with a spacer and fits on a 10-speed wheel just fine. No need for Dremel or redishing.
— Alan

Dear Lennard,
Joseph asked about using a reduced 11-speed cassette on a 10-speed freehub. I did that about three years ago when I was trying to build a gravel bike on a budget. I found a deal on a pair of 29er wheels that fit the bill except for 11-speed compatibility. The cassette I wanted to use was an 11-speed 11-32 Shimano 105. The three largest cogs were on a carrier, but all the remaining cogs were individual. I had to buy a 13-tooth, second position cog and a 12-tooth outer cog to replace the 11, 12, and 13 cogs of the original cassette, and it all fit together perfectly. I set the limit screws so that I can’t use the last click in the shifter, and it’s still working great three years later. I rarely ever use the 50×12 on that bike, so I’m not really missing the 50×11 anyway.
— Quentin

Dear Lennard,
I was reading with interest your response about fitting an 11-speed road-bike cassette on a 10-speed freehub with Shimano 11-speed road-bike shifters.

Your response brought me to a YouTube video where it mentions that approach (and which spacer to omit) as well as six other alternatives. But more importantly, one of the viewer comments mentions an even better way; simply use a Shimano 11-speed MTB cassette on the 10-speed freehub. Apparently, that works because the largest cog is concave on the side where it butts up against the freehub (just like 11-speed campy cassettes are).

I think this is the most straightforward method next to installing an 11-speed freehub (if it truly works).
— Demetrius

Dear Lennard,
I noticed that you said that 2009 Veloce was Powershift — it wasn’t. It came out as Ultrashift and changed shortly thereafter. The user can potentially still fix his shift levers.
— Stephen

Read the full article at Technical FAQ: Aluminum frame, crankarm fatigue on VeloNews.com.

Tech FAQ: Fixing Campy shifters and converting drivetrains


Have a question for Lennard? Please email us to be included in Technical FAQ.

Repairing Campy shifters

Dear Lennard,
I read in your well-known repair manual (which I own) that some Campagnolo shifters may be repaired by replacing the G spring and its retainer. As I understand, this does not, however, apply to models from 2009 onward, as the design of the shifter is different. My Campagnolo Veloce right shifter skips over the lower cogs, often going right to the smallest when I downshift. I believe there’s a problem with a return spring.

Is it at all possible to replace a broken spring or other components within the shifter itself, in order to repair it? I have experience repairing laptop computers, so I’m not concerned about taking the device apart and re-assembling it. Rather, I have not been able to find any replacement parts and few if any published procedures. Everything seems to apply to the older, pre-2009 models.

The only option I see is to replace the shifter body (and transfer the brake lever and hoods), or buy a matched set of the newer version which has a more ergonomic shifter button. I do wonder whether this later (2015?) model will be even less durable than my original one, however, as I’ve read complaints of them failing prematurely.
— Marc

Dear Marc,
The mechanism in your Veloce shifter is called Power-Shift. That lever body incorporates neither the older G springs clicking into an indexing ratchet nor the more recent Ultra Shift technology (a spring-loaded detent ball dropping into tabs on the face of a disc). Most likely, the pawl inside your shift lever body that is actuated by the thumb lever is damaged or has failed. This is not repairable, as the pawl is riveted into position in the body.

The possible solutions are just as you suggest. One is to replace your single lever body with a new Campagnolo EC-CE300. Or, as you said, you can replace both levers with new Veloce Ergopowers. The current model has the same internals as your model. Externally, the newer Ergopowers have a longer, lower thumb lever for ease of reach while in the drops.
― Lennard

Cyclocross drivetrain choices

Dear Lennard,
I have a small quiver of wheels forming for CX season, and just as I was getting everything to wider, 23mm internal rims, I’ve run into the 10- vs. 11-speed conundrum. I began wondering if you’d tried yet, with or without success, installing an 11-speed cassette on a Shimano/SRAM 10-speed style FH body by sliding on 10 cogs from an 11-speed cassette. I’m thinking (much like some downhiller guys who run 9- or 10-speed spacing on short BMX or SS style freehubs — Chris King or Industry Nine SS hubs — by using 5 or 6 cogs/spacers) I could get away with using an 11-speed cassette (with one cog and spacer left out) on a 9/10 FH equipped wheel on an otherwise 11-speed bike. I was thinking:

1. You’d have to have the small cog so the lockring interfaces well.

2. Once you get to spidered cogs, those will have to be there.

3. Do you know which cogs are separate and which are spidered?

4. would Shimano or SRAM 11-speed cassettes work better in this instance? Obviously, the low limit would need to be adjusted to not throw into the spokes, but other than that what am I forgetting? Or is it the high screw as well?
— Joseph

Dear Joseph,
I have not tried that, but if you were to take out the second-smallest cog and its spacer, it would, in theory, work. It would require a cassette in which at least one of the small cogs other than the first cog is separate, which eliminates high-end SRAM cassettes from consideration.

When installing this wheel into an 11-speed bike, yes, you would need to tighten the low-gear limit screw to avoid the derailleur touching the spokes and the chain jamming between the cassette and the spokes. The high-gear limit screw will probably need to be tightened in a bit too.
― Lennard

Feedback on cycling and aging

Dear Lennard,
I’ve followed your writing for years (you even answered a question of mine about 14 years ago about ceramic bearings before they were really a thing), and I have always appreciated your willingness to share information with us! Helpful, clear and practical, you are a go-to for tech questions, especially those that relate to special circumstances like mixing parts groups, etc.

I am writing in regards to your column about getting older as a rider. Frankly, it might be the most helpful thing I’ve read this year. As a 44-year-old cyclist, I’ve had significant health issues (unrelated to cycling) in past years which have lifted, and so my riding has increased significantly in the past two years. I’m a former competitive runner and coach, so I KNOW how to train, particularly regarding intensity and periodization. The problem I’m finding is that Zwift (a great tool for those of us in the Canadian snow belt!) tends to have me riding hard all the time. Your article was extremely timely, as I’ve been warring with myself; as my training hours are up, my fitness is up now that I am healthy. The tendency is “if some is good, more is better,” but your column was a good reminder me to stick to my program, both with myself and my athletes, and not get sucked into the Zwift/Strava trap of riding hard always.

Thank you so much for what you wrote. I will be sharing this with some of my athlete friends, because I think our current online tech world is going to precipitate a crisis in the next few years as the 40- and 50-year-olds inadvertently overtrain to the point of doing lasting damage. I’m concerned that we are going to see a sharp spike in cardiac issues in the next few years as too many of us chase records, stats, and social comments at the expense of healthy and wise patterns of training. The irony of fitness making us seriously ill …
— Jorin

Dear Jorin,
I am concerned about that as well; it stimulated me to embark on co-writing The Haywire Heart. We are the guinea pigs — the first generation to be pursuing these kind of athletic goals so late in life, and it is possible that we may so far only be seeing the tip of the iceberg in terms of cardiac issues among competitive masters endurance athletes.
― Lennard

Dear Lennard,
I just read your interesting discussion of athletic activity that compromised your health later in life. For most cyclists, especially those who are lightly built, I would add the recommendation to do some running almost every week to maintain bone strength. Research has shown that those of us who ride bikes more than 10 hours/week at the exclusion of weight-bearing exercise are more likely to have osteoporosis than if we sat on a couch instead. You can be comfortable and competitive on the bike if you have osteoporosis, but a seemingly minor fall will result in a broken bone.
— Larry

Dear Larry,
Thanks for that. I should note that walking and skiing also fall into that category of weight-bearing exercise, for those of us whose joints don’t allow for running.
― Lennard

Read the full article at Tech FAQ: Fixing Campy shifters and converting drivetrains on VeloNews.com.

Technical FAQ: How cyclists can keep on rolling as they age


Dear Lennard,
In reading your post on seats and reflecting on your tech reporting as of late, it seems to reflect the surprising fact that you’ve aged. This is fine by me, as I’ve run out of fingers and toes to keep track of my age. This thought made me want to ask: What would you have done differently that might have improved your ride experience as you aged? Or more generally, looking back do you think there are habits among younger riders that cause injuries/issues later in life that could be avoided without loss of youthful performance? For instance, extreme difference between high seat height and bar slammed down. Does this actually improve performance but is a young rider’s game and an old man’s sore neck?
— Jeff

Dear Jeff,
That’s a very interesting question, and it wasn’t until I started thinking about it that I realized I’ve been writing for VeloNews almost half of my life! I am now 60, and when I started at VeloNews in 1989, I was 31; I’m coming up on my 30th anniversary with VeloNews! Some things do come to mind that I think would have changed my current physical issues if I were to get a do-over while pursuing the same goals.

First, the chronic injuries I have lived with, most of them for decades, are:

  1. Heart arrhythmia; this appeared five years ago. In doing the research for “The Haywire Heart,” I have come to look at this as an overuse injury.
  2. Degenerative low back disease — complete loss of disc space between many of the vertebra in my low back first diagnosed over 20 years ago. Some medical professionals I have been working with on my current chronic high hamstring injury believe that the source of it may be pinched nerves in my low back.
  3. Chronic left shoulder problems for over a decade — ruptured long head of the biceps tendon, dislocation, rotator cuff tears resulting in two recent surgeries to repair those tears.
  4. Left elbow tendinitis — medial epicondylitis (“golfer’s elbow”) for over 20 years.
  5. “Morton’s neuroma” in between the joints of the metatarsals in my feet for over 20 years.
  6. The one most limiting my “ride experience” is my heart, which I would reduce the stress on if I could go back and do it over again. I see this from two sides — emotional stress as well as physical stress.

On the physical side, I think I could have reduced the injury to my heart by prioritizing rest and reducing total training volume while being more judicious with intensity training. I also would have spent more time relaxing and less time preparing multiple bikes, multiple wheels and tires, and, in the case of cross-country ski racing, multiple pairs of skis with a ridiculous number of layers of wax interspersed with fastidious scraping and brushing on each. I think my heart would have experienced less total stress (and my results may have improved) if I had instead rested rather than prepping equipment late into the night before races.

As for emotional stress, maintaining a more laissez-faire attitude toward race results would have served me well my entire life. I tended to place too much importance on them (I made poor results mean something negative about me), which I think increased the stress on my heart. It also drove the crazy amount of bike preparation and ski preparation in anticipation of and schlepping of equipment to races. Early arrival and calm warmup the morning of cyclocross and cross-country-ski races instead of the rushing around loading and unloading equipment from vehicles and trying different tires or skis on the course would have better served my heart. And accepting the occasional race where I didn’t have the ideal tires or tire pressure or hadn’t selected the ideal skis and prepped them with the ideal wax would also have been good for my heart.

I believe the discs in my low back would be healthier now if I hadn’t injured them repeatedly alpine ski racing and hard mogul skiing and then exacerbated it by sitting too much and not having enough regular movement, particularly rotational movement, of my spine. I think the following things would have reduced my current symptoms:

  1. Less high-speed bump skiing and less back bend while doing it.
  2. More awareness of sitting posture (I discovered too late sitting on this inflatable pad with proper ergonomic keyboard and screen setup.
  3. Limited duration of sitting (getting up more; using a standing desk).
  4. Consistent overall-body and core-strength conditioning starting in my teens without the hiatus I took from kayaking (it rotates the spine as well as works the core) between ages 20 and 45.

As for a slammed stem in my youth affecting me long-term, I’m not sure. I do believe overly short top tubes for my long body caused a curve in my back while riding that was not healthy, but once I started making my own frames at age 24, that was no longer an issue. My chronically stiff back always felt better after getting on the bike and also when coming off of the bike, except after exceptionally long or hard rides.

Until age 30 or so, the drop from the top of my saddle to top of my handlebar tended to be around 10 inches (250mm). As I have aged, that differential has reduced, and as my back has shortened due to flattened discs, my top tube length has also shortened. The canary in the coal mine was generally my shoulders; as I got older, these things seemed to cause me more shoulder pain than neck or back pain.

As for the second part to your question about potential performance improvement or not with the slammed stem — I think we generally understand now that a narrower hand position does more to reduce aerodynamic drag than does a lower hand position. I think that many racers leave climbing performance on the table with too low of a handlebar, and that may also haunt them later in life.

The narrow descending tuck position that I used in my 20s and 30s and can no longer sit in due to neck pain is not really affecting me now due to changes in bike design. By the time I could no longer tuck with my chin on the bar and my butt on the saddle, my bikes had sloping top tubes, and I could descend sitting on the top tube with my chest on the stem. The “Sagan position” does not hurt my neck and is as fast as either “Nibali position.” Otherwise, my neck doesn’t bother me riding, so I’m not regretting years of low handlebars.

The shoulder issues first started from too much reach and drop to the handlebar as my low back stiffened and shortened, combined with overuse injuries from cross-country skiing. These resulted in spontaneous rupture of my biceps tendon while riding my bike up a steep canyon. Resulting instability in the joint increased damage during bike and ski crashes — one that dislocated it and others that tore rotator-cuff tendons. Keys would have been treating positioning and overuse issues earlier and reducing crashes with less emphasis on race results mentioned above. I think crashing often can be avoided with a more long-term perspective on life and what’s important, something often lacking in one’s youth. Fewer crashes definitely can result in an improved ride experience in later life.

Elbow injury — knowing what I know now, I would not have created that overuse (offseason cross-country ski training) in the first place.

Neuroma in feet — not understanding my foot type, shape and biomechanics led to this. Orthotics with metatarsal- and medial-arch support, cycling shoes and ski boots wider in the forefoot, and a more rearward cycling-cleat position treats this and may have prevented it.

The good news is that, due to sciatica pain, the disc problems in my low back kept me from running, bump skiing, and heavily-loaded backpacking for the past 38 years and steered me toward non-impact sports. I think that my knees, hips, and ankles have no chronic problems, thanks to a lifetime of cycling, cross-country skiing, rafting, and kayaking to the near exclusion of other sports.
― Lennard

Read the full article at Technical FAQ: How cyclists can keep on rolling as they age on VeloNews.com.

Technical FAQ: Drivetrains and handlebars on a recumbent


Mixing drivetrains and bars

Dear Lennard,
Due to injuries that I suffered when hit by a distracted driver two years ago, I have had to abandon my fleet of road and ’cross bikes in favor of a recumbent. I purchased a used Schlitter Encore, which came with a SRAM mechanical MTB triple groupset with bar end shifters. I hated the shifting.

I swapped to Shimano RS700 flat bar shifters combined with an Ultegra RX800 clutch rear derailleur, an FD8000 front, and an FSA K Force Light 50/34 compact crank. The shifting performance improved, but I am having issues with the rear. It sometimes struggles to shift to a higher gear, and all attempts at adjusting it on my own in accordance with the Shimano manual specs don’t improve it.

I have concluded that the problem is the extremely long cable used on the bike. I am considering setting up the bike with Di2 shifters. I have two issues. Are there any flat bar Di2 shifters (eg XTR) that will work with road Di2 derailleurs? If the answer to my first is yes, does Shimano offer very long Di2 wiring that I can use to hook up the rear mech?

See the photo of my Encore (above) that gives you an idea of what I am dealing with. Your road bike maintenance books have saved me many times!
— Jim

Dear Jim,
Absolutely, there is such a solution! Just make sure you don’t mix derailleurs, however. As long as you use both road Di2 front and rear derailleurs (Dura-Ace or Ultegra) along with the Di2 MTB shifters (XTR or XT), it will work. Road Di2 shifters will also work with MTB Di2 front and rear derailleurs, but neither shifter set will work with an MTB front derailleur and a road rear derailleur, or vice versa. Also, I think that using the Di2 full Synchro Shift (“S2” mode) will be a tremendous advantage on a recumbent.

We recently built a custom titanium bike with the same shifting system you want and for similar reasons; the guy we built it for also needed a unique bike due to being hit by a distracted driver. He is a triathlete who was hit on Alii Drive in Kona a few days before the Ironman World Championships eight years ago. He still raced that Ironman despite the severe injury he suffered, but his cervical spine deteriorated rapidly afterward. He now has a pair of long rods implanted in his back on either side of his spine that go all the way up to the base of his skull. The rods prevent him from being able to turn his head or tilt his head back. Since he can’t lift his head if his torso is leaned forward in a riding position, he needs to sit bolt upright. Hence the ape-hanger handlebar and super long head tube and fork steering tube.

We built his bike with a banana seat custom made out of carbon fiber by Craig Calfee and a custom titanium sissy bar from Black Sheep supporting it with multiple water-bottle mounts on it. The long saddle allows him to sit in numerous positions, and the sissy bar gives him something to push against when sitting upright, because pulling on the bar in that position accomplishes nothing. There is a video camera mount on the sissy bar below the saddle, which enables him to view what’s behind him on a screen on his handlebar, since he can’t turn to see what’s there.

Zinn custom bike
Photo: Lennard Zinn

The custom titanium ape-hanger handlebar includes a drop bar that he can pull on when standing out of the saddle and which supports an aero bar (with Di2 remote shift buttons on it) that he can ride while keeping his head up by sliding to the forward tip of the banana seat.

Shimano’s Di2 Synchro shifting allows uncompromised riding with all sorts of injuries. If shifting with one of the hands is impossible and the rider still wants a double or triple front chainring, then S2 (full Synchro-Shift) mode allows all of the shifting to be done with one hand. It also doesn’t matter which hand; by using either a tablet or smartphone and a wireless app or a PC and a wired interface, you can customize which shifter does what.

In your case and in the case of the rider we built this bike for, S2 Synchro-Shift mode allows you to make intelligent shifts without ever needing to see what gear you are in. (While looking back would be impossible for him and may be for you on the recumbent, you do have the option of viewing the gear combination on an MTB Di2 digital display or on a Garmin or other ANT-enabled and Di2-knowledgable bike computer?) It takes consistent gear steps for maximal use of your gear range; you get unique, evenly-spaced gear ratios without jamming or dropping the chain.

In S2 mode, it will keep the chain on the big chainring while downshifting through the first 10 cogs from the smallest to the second-largest rear cog; only then will it finally shift to the inner chainring at the same time that it drops the chain back down one or two rear cogs. And then it goes through the lowest gear combinations from the small front ring to the biggest rear cogs. On the way up, it stays in the inner chainring as you shift to ever-smaller rear cogs until about mid-cassette, when it (after warning beeps) shifts to the big chainring while shifting back to larger cogs. Don’t like when it makes which shift? You can program where on the rear cassette you want the front shifts in either direction to occur as well as how many cogs it shifts back in the opposite direction when doing the double shift.

To answer your second question, Shimano makes Di2 E-Tube wires up to 1400mm in length. If that is not long enough, you can use an EW-JC200 2-port junction or a second Junction B to splice two wires together.
― Lennard

Read the full article at Technical FAQ: Drivetrains and handlebars on a recumbent on VeloNews.com.