Category: Bikes and Tech

Interbike Gallery: Day 3 and Reno Cross

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Craftsmanship and history: A tour of Italian cycling factories

Earlier this summer VeloNews traveled to Italy with the Italian Trade Commission, a government-funded trade promotion entity that promotes the country’s cycling companies.

Ernesto Gazzola’s house outside Maser in the Veneto region of northern Italy sits on the grounds of the shoe factory he founded in 1962. If you walk out of his back door and cross a small lawn, you come to a gleaming large, white sliding metal door. The door opens into a soaring, 43,000-square foot ultra-modern production facility that produces high-end cycling shoes for Gazzola’s brand, Gaerne. About 40 workers use presses, stitching machines, molders, and their own hands to produce approximately 200,000 high-end motorcycle and cycling shoes each year.

From the front door of his home, Gazzola hears the tap, tap, tap of his cobblers as they flatten seams on the shoes with specialized shoemaking hammers prior to the final stitching. The entire operation is, and has always been, under his gaze.

VeloNews recently traveled to Italy to tour the factories of some of the country’s smaller cycling brands. The purpose of the trip was to showcase just how healthy the country’s cycling manufacturing industry still is — and how much of the work is still designed, prototyped, and created under the same roof.

It was fitting that one of the trip’s main focus was on three mid-sized manufacturers of cycling shoes: Gaerne, DMT, and Vittoria. What has kept most high-end Italian shoe production from moving abroad is the sophisticated ecosystem of Italian-based suppliers who provide every component that goes into modern cycling shoes. Adjacent to the shoe factory are the workers who molds lasts, lay up carbon-fiber soles, stamp out buckles, inject plastic, etc. As Gaerne’s Marta Gazzola says: “Just like a good pasta, all the ingredients have to be good!”

The manufacturing equipment used to make shoes – presses and stamping equipment, super-specialized, industrial-sized sewing machines, and finishing grinders and mills — typically also made in Italy. Oftentimes the workers who run the machines are former bicycle racers themselves. At two of the factories we visited, ex-pros and elite-level amateur racers strolled onto the factory floor after their respective morning rides, to give production staff and designers immediate product testing feedback.

We witnessed several other trends at these factories. We saw generations of the same family working side-by-side. Owners often live on-site at the factories. At the Gruppo Zeccheto factory, which produces goods for DMT shoes, Alé apparel, and Cipollini bicycles, founder Federico Zecchetto lives in a house quite literally on the factory grounds.

Across the globe, shoe production has become an automatic process, with elaborate multi-step production processes that rely on machines. What we saw at the factories of Gaerne, Vittoria, and DMT were production processes that relied heavily on human hands.

At Gaerne, a consistent hum of the production process filled the factory floor — absent were any erratic loud noises, yells, or stops and starts of equipment that you often hear in other factories.

Once known largely for its motorcycle boots, Gaerne’s first cycling shoe was produced in 1985. Today the brand has produced approximately 80,000 pairs of largely high-end shoes. The company has annual revenues of 18 million euro. Cycling stars such as Fabio Aru, Andre Greipel, Chris Horner, and Fabian Cancellara have won major races wearing Gaerne shoes.

Gaerne continues to work with top pros. A representative said that the company’s pro rider sponsorships are tricky, due to the fluctuations in shoe size that go on during a typical season. A shoe that fits perfectly in January may be too tight in July, as a rider’s feet swell from the heat, thousands of training kilometers, blisters, and crashes. Often times, a pro must size up a half or entire size from the start of the year until the Tour de France.

Photo: Felix Magowan


As he was winding down his professional cycling career, Celestino Vercelli founded Vittoria cycling shoes in 1976 in his hometown of Vigliano Biellese, located between Milan and Turin. Vittoria’s home is nowhere near Veneto, the traditional center of Italian shoe production. Yet Vittoria has found ways to be ahead of the curve. Vittoria was among the first companies to pioneer the use of microfiber uppers (as opposed to traditional leather). It also developed a dial-closure system in 1992, six years before the founding of industry leader Boa.

Today, the company produces 130 pairs of shoes each day. The volume allows Vittoria to do custom orders — it will create special colors to match any team kit. Vittoria continues to produce award-winning shoes today. The brand’s Velar model won the Design & Innovation Award 2018.

Just down the autostrada from Vittoria at Gruppo Zecchetto’s sprawling complex in Bonferro di Sorga, we saw another unorthodox dynamic at play in Italy’s shoe industry. Some of these companies produce products that are then bought and sold by other top-tier brands. At Gruppo Zecchetto’s DMT factory we saw shoes being affixed with the familiar swoosh symbol of Nike. Company representatives said Lance Armstrong’s Nike’s were often sourced here at DMT.

Adjacent to the Gruppo Zecchetto’s sprawling facility is APG, one of the most sophisticated custom sublimation factories in the world, even though it’s barely known outside of the apparel world. APG for decades produced high-end kits for Giordana and Nike — yes, including Armstrong’s kits. While other famous names such as Vermarc still use APG, the company now focuses on building its own brand, Alé.

Known for its electric colors, Alé kits are also produced in a unique manner. Every step of the production is done in-house. The company’s design studio is electronically linked to a proprietary in-house custom sublimation printing process. After a kit is printed, it is cut, sewn, and pressed at the facility. Alé even makes its own chamois in-house, rather than sourcing from chamois suppliers.

The third company headquartered in Gruppo Zecchetto’s complex is Cipollini bicycles. Yes, it is named for the eponymous flamboyant sprinter Mario Cipollini, who was famously fastidious about the design, manufacture, fit, and finish of his racing bicycles. As he approached retirement, Cipollini launched his own brand, partnering with Gruppo Zeccheto to realize his vision.

Like Alé, Cipollini bicycles manufactures its carbon in-house at the facility.

Cipollini’s carbon is made in-house. Photo credit: Felix Magowan

A trip to visit Italian bike companies would not be complete without visiting an artisanal, high-end custom framebuilder. We toured FM Bike, a custom e-bike brand. Founder Michele Favaloro makes his made-to-measure e-bikes out of 100 percent Italian equipment (Polini motors, Deddacciai aluminum tubes). As one of the first builders to build custom electric bikes FM has built quite a following, as the bikes handle like a good, un-assisted road bike. Wait times from placement of order to delivery is on average just 30 to 40 days, says FM.

Our final stop took us to Selle SMP, the saddle manufacturer that is located just outside of Padua. Founded in 1947, Selle SMP in the late 1990s produced about 5 million, mostly low-end saddles, which it sold to other brands across Europe. In 2000 the brand decided to break into the upscale market for saddles. This move corresponded with the rise of Asian manufacturing, which put the company’s entire business in jeopardy. The Schiavon family scrambled to come up with a new playbook.

Their solution was addressing an age-old problem: pain in the butt. More specifically, Selle SMP felt traditional saddle designs caused genital numbness and tingling. Could a better saddle overcome the problem?

Selle SMP commissioned a research project, hired urologists and gynecologists, and created prototypes. The efforts created the first saddle with a full-length “central channel” cutout design that has been copied by other saddle manufacturers. Other key designs came from the research, such as a drooping saddle nose, designed to reduce genital compression. When the droop saddle nose was introduced at the Milan trade show in 2004, a representative said the company was practically laughed off the show floor. The saddle’s look was simply too strange. But as years went on, riders flocked to the design.

“Rather than be focused on fashion we focused on ergonomics and coming up with saddles that put comfort and performance first,” said company representative Nicolo Schiavon. “We were behind at the time, so we had to gamble and didn’t really care what other people thought.”

A decade after that first saddle, nearly half of Selle SMP’s production is now under its own brand, and the company’s revenue has more than doubled. All production is Made in Italy, and Selle SMP is the leading independent saddle brand sold at dealers in markets as diverse as Italy and Korea.

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Emily Kachorek Q&A: Gravel growing with better gear

What is behind the bike industry’s trend toward gravel riding? Some of it is a response to consumer demand. Some of it comes down to simple economics — capitalizing on a growth sector. But the cycling industry is driven by passion, and that can dictate why bike companies do what they do. Emily Kachorek is co-owner of Squid Bikes, a small frame company in Sacramento, California. If you ask her, the advent of new gear is making it more accessible and exciting for people to ride dirt and gravel roads, rekindling their passion for cycling. We caught up with her earlier this year to get her take on where the bike industry is headed.

VeloNews: What sort or riding or technology gets you excited these days?

Emily Kachorek: Generally when the sun’s out and I have an opportunity to be on my bike no matter what, I’m pretty stoked. I spend most of my time on the dirt now and don’t spend a lot of time road riding or racing. To me, it’s going out and exploring new roads. If I have a free weekend and don’t have anything to do, it’s getting out Google Earth and kind of flying around and trying to open up more of the stuff in the Sierra Nevada because there is so much good riding out there and so much of it is unexplored. For me, it’s the Sierra Nevada. For other people, it’s their local mountain range or even farm roads. Just trying to plan new roads.

Another thing we’ve wanted to do forever and still haven’t, although we have a route planned, is to do is riding from the Sierra Nevada Brewery to Sacramento or vice-versa all on dirt. [The Squid crew did this ride later in the summer after we spoke.]

Just finding new ways to explore roads and connect new places and turn it into an adventure.

VN: Do you think the emergence of this technology is a response to that interest or is it provoking more?

EK: I think it’s probably a little bit of both, to be honest. People have always been out exploring the back roads. Certainly, technology that’s more reliable and makes it easier improves that and more accessible for more people. I think with a lot of the new gravel races and different-style events like Grinduro that are popping up and really catching on. Even technology like new computers, mapping technology is making that more accessible.

VN: On that note, what sort of organized events are gaining traction? Gravel races?

EK: I think so in terms of just stuff that’s new and different. At least speaking for myself and my friend groups, the idea of going out and doing a race every single weekend is a lot for people to take on.

If I can do just three or four events a year but they are big marquee events that still provide me some motivation to train every day, and you can go camping with your family and have it be an event and a full weekend rather than commuting back and forth or business park crits. To me, that’s what I see my friends getting excited about. Have it be built around a full weekend and a lot more about community, rather than winning and losing.

VN: Is there anything right now in the bike industry that seems like a fad?

EK: I’m not like super-into the geeky side of the technology stuff. I’ve got my tried-and-true one-by and my singlespeed, and I’m pretty good with that.

I think some of the new mapping tech is pretty cool. I’ve never been a big computer person either. It seems like it opens up some new ways to explore on bike.

VN: Mapping is not a fad …

EK: [Laughs] Maps are helpful!

It seems like the bikepacking thing — I have done touring a long time ago, 10-plus years ago. It seems like that is gaining in popularity. You see a lot of new bag companies out there. That’s stuff that makes it more accessible to people and that’s kind of cool.

There’s that big Baja ride that’s gained traction in the last three or four years. It’s basically San Diego down the coast of Baja. I have a number of friends that have done that. You definitely need to have a big chunk of time to go do those type of adventures. But I think they are inspiring for people to go and do mini adventures on the weekends.

I have friends that will pack up their shit and go 10 miles out past their normal long ride, but then they get to camp and hang out and again it’s a different experience than going home and showering, changing, and drinking your protein shake.

I think people mixing it up is what we’re seeing.

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Interbike Gallery: Day 2

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Bike Gallery: Denise Mueller-Korenek’s record-breaking KHS

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Interbike gallery: Day 1

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Industry insiders: What new technology could be a game-changer?

Earlier this year I spoke with bike industry stalwarts to get a sense of the industry’s direction. I asked a series of broad questions and received some interesting answers.

My second question focuses on how technology can change the way we ride. Is there a new product, or a product in development that has the potential to be a game-changer?

These responses have been edited for length and clarity.

Joe Breeze, Breezer Bikes

What I would love to see is a transmission that can stay clean and efficient. The chain is still the most efficient way to transfer power known. And wouldn’t it be lovely to keep it clean all the time? Especially for a mountain bike, wouldn’t it be nice to enclose that chain? Perhaps with these transmissions coming along, that is not a derailleur transmission, up near the cranks perhaps. That you could have a single chain going to the rear wheel and have less unsprung weight at the rear wheel no less, maybe have the chain covered by a chain case of some sort. Fifty years down the road when you go to inspect the chain you’ll see a nice clean beautiful chain.

Scot Nicol, Ibis Bicycles

What I’m most excited about now is tire and rim technology. Now we’re all running tubeless and using wide rims. Those two factors, the wide rims combined with the low pressures you can run with them, has been an amazing game-changer. Some of my bikes I’m running like 15 psi and the traction is unbelievable. That for me is where it’s at.

John Parker, Underground Bike Works, founder of Yeti Cycles

I think the oversized tires have changed everything — brought me back into the industry. I was living on the beach in Ventura, was down on the shore looking for beach glass. I saw a guy on a fat bike, and I instantly had to have one. It’s the most fun I’ve had on a bicycle in many, many years.

Although that was great for riding down on the sand at the seashore, back in the day Doug Bradbury and I had always talked about what this sport really needed was oversized, bigger tires. Doug went so far one time, he took wheels off a 75cc Kawasaki motocross bike made his own hubs and laced them to a mountain bike. They were prohibitive in the weight but the thought and the idea was there. 1997, we were using the same size tire that Ignatz Schwinn took to the 1939 Worlds Fair.

I remember sitting with a young Kozo Shimano in my booth one time and telling him the only thing we need now is disc brakes. The drivelines, the disc brakes, the tires, the suspension. It’s rather provocative now how great it is. This was the beauty of mountain biking when I started. Everyone went into their garage with a dream of making something. And now it’s wide open. I can’t say there’s just one thing, but the ride, the technology, the improvements, for me it started with these oversize tires. Every bike I’m going to make from now on will be a plus-size-tire vehicle.

Gary Fisher, founder Gary Fisher Mountain Bicycles

The whole electric-assisted bicycle thing is what I’m interested in. It is the world’s most efficient motorized transportation, and I think we should be very proud of it. I think the way it’s being sold can also be something we learn from. We’ve identified 700 bike shops in the U.S. that only sell electric bikes. Those guys have a much different way of selling things. I tell my regular shops to go in and check out the way they do business because we can all learn from them.

Richard Byrne, Speedplay pedals

I think disc brakes are the latest potential … I mean they’re not new. I think Phil Wood had them first for road bikes a few years ago.

What they’re doing to bicycles is they’re giving designers the freedom to use larger tires and rims and making it where bikes bridge the gap between road bikes and mountain bikes. And you can have one bike that’s practical for a lot of different purposes, and I think it’s a game-changer.

Chris Chance, Fat Chance Bikes

I don’t have anything that comes to mind to point my finger at directly. But I’m really excited about how things are evolving in the bike business. People are doing a lot of refining, looking at what works, what doesn’t work. What survives is really serving us now. I love talking to people about how, say, their old Yo Eddy Team Fat Chance was their favorite bike years ago. They get on a new one and say ‘Wow this is even better, I couldn’t even imagine back in the 90s it would get even better than this.’

The culmination of all this experience and technology and honing and refining I just find really exciting. We’re riding this wave of ingenuity in parts, geometry, tire design, wheels, brakes, you name it. It’s really getting somewhere.

Tom Ritchey, founder Ritchey Logic LLC

If there was a game changer, we wouldn’t notice it, because there are so many people getting lofty ideas that everything is a game changer! We’ve lost the ability to even recognize one. From my perspective, the only thing that matters is that the uniqueness of the bicycle and its elemental components that exhibit the utility of a bicycle are there. That’s a game changer. Whatever it is that gets people into riding will be our future. Electricity will be in our future, but to the degree that we’re [riding] without electricity and that makes us feel like we’re in control and making it down the road, that is a wonderful thing.

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Technical FAQ: Headset spacer stack height

Headset spacers

Dear Lennard,
I have seen several references that suggest that 30mm of spacers below the stem is the maximum you should have for a full carbon fork steerer tube. I have seen others that say 40mm would be the maximum. What is your position on this matter?
— Richard

Dear Richard,
Even though people want a blanket answer to this question, there is no way such an answer can be given because it depends on so many things.

Obviously, stress on the steerer and how many spacers can safely be used depends on the construction of the steering tube — its wall thickness, types of fibers incorporated and their orientations, the resin used, and the compaction and complete wetting of layers with resin.

It also clearly depends on the weight of the rider and his or her position on the bike, which determines what percentage of that weight is resting on the handlebars. Another critical dependency is how long the stem and handlebar are, as greater leverage puts greater stress on the steerer. The shape of the stem clamp and sharpness of its lower edge also affects the stress on the steerer.

Finally, the spacer height that can be safely used depends on the type of riding the bike will be subjected to. If the rider pedals it gently on smooth roads, the answer will be different than if he rides it into curbs and big potholes or off of semi-truck loading docks.

I have a philosophy on this that is colored by the fact that I design and build both custom and non-custom bikes for very tall, and often very heavy, people. I don’t want to ever have a steering tube fail, and, for that reason, we use a long, glue-in aluminum insert inside the top of carbon steerers on the bikes of big riders. Only then am I confident enough to use a tall spacer stack on the fork steerer.

Tall riders who do not have a custom frame that fits them often have a big spacer stack of as much as 100mm under their stem in order to get their handlebars high enough. They are playing with fire, in my opinion, if they have a carbon steering tube and don’t have one of our inserts inside the steerer. Breaking a steering tube is a guaranteed crash. And even flexing the steering tube, when flex is an issue for the entire bike and fork for any tall, strong, heavy rider, reduces efficiency and control.

We go to considerable expense and extra effort to install our glue-in insert system in the carbon steering tubes of forks that go on bikes for tall and heavy riders, as it provides a greater margin of safety for big riders. We have never had a customer break a carbon steering tube, and we intend to never have it happen; going to all of this extra trouble is our way of further ensuring it doesn’t happen.

Most carbon forks come with a simple expander system that is about an inch long. We feel that it doesn’t give us the same certainty of longevity of the fork steerer, nor does it provide as much stiffness to the steerer as ours does. Those expander inserts ONLY support the steering tube directly under the areas inside the stem clamp. Worse, if the user has a tall spacer stack above the stem, there may be no support at all inside of the stem clamp. And, critically, even if the expander is in the right spot inside of the stem, it provides no support of the steering tube below the stem. That may be enough, and for most riders it probably is, but I insist on a bigger margin of safety for a really big rider; I want to reinforce a long way down inside of the headset, even if the rider uses a bunch of spacers below or above his stem, or both.

Long ago, we had True Temper make special carbon forks (called Alpha Q Z-Pro) for us for tall bikes; they had 450mm-long double-thickness steering tubes. Despite that extra thickness, True Temper supplied, and we used, a four-inch-long, glue-in insert for them (it was an Alpha Q insert for a 1” steerer, rather than for a 1.125” steerer; because the steering tube wall thickness was so great, that’s what fit).

When True Temper quit making carbon fiber bike equipment, Ben Serotta, who had bought the Reynolds Composites factory, made carbon forks for us with 450mm steering tubes. When Serotta shut its doors in 2013, ENVE made us rim-brake forks with 400mm tapered steerers. Now, ENVE offers the Gravel Road Disc fork with a 400mm tapered steerer. Both of these steerers have the same wall thickness at the top as all ENVE forks and come with a standard expander plug. Since I have never heard of an ENVE steerer breaking, maybe I’m being overly cautious, but I don’t want to mess around when building bikes for 6-foot-10, 350-pound riders; consequently, we get special glue-in inserts made specifically for these forks.

The Alpha-Q insert was four inches (100mm) long and had a star nut pounded down into its bore. Wheels Manufacturing, which is conveniently located near us, now makes us a five-inch-long (125mm) aluminum sleeve insert with integrated thread inside for the top cap bolt. We glue it in with JB Weld epoxy.

We first sand inside the steerer, blow it out with compressed air, and wipe it clean inside with a clean rag soaked in rubbing alcohol. After epoxying it in, we leave it sit for 24 hours before adjusting the headset and tightening the stem clamp.

We sell that insert separately.

For a while about nine years ago, Isaac made a 60mm-long expander plug, which I think is also a more secure method than standard expanders, but I don’t believe those exist anymore.

Anyway, that is a very long answer to your question. If you are a lightweight rider who sits up very high on the bike with the handlebar much higher than the saddle (so that little of your weight is on your hands), and you ride on smooth terrain at relatively moderate speeds, you can probably get away with a very tall spacer stack (probably as tall as you want) on almost any carbon fork while using the standard expander plug under the stem clamp. But if you are heavy, ride with a long stem, and your handlebar is far below the height of your saddle, you should be cautious about using more than, say, 25-30mm of spacers. Same goes if you ride your bike fast on rough terrain.

I just don’t think I can give a blanket answer to this question that is more specific than this.
― Lennard

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Week in Tech: XC from BMC, Enve trade-ups, Bianchi-Starbucks mash-up

Here’s the Week in Tech — all the gear news, tips, and announcements you need and none of the marketing gibberish you don’t.

BMC’s Fourstroke features non-round dropper post

“XC is dead.” —Everyone, four years ago.

Like so many of its competitors, BMC has sniffed out the resurgence of XC and continued its play into the game with the Fourstroke 01. It’s a lightweight, short-travel XC tool with some tricks up its sleeve. Most notably, the Race Application Dropper (RAD), is an integrated system that allowed BMC engineers to move away from traditional round seatposts. The elliptical shape of the post saves weight while maintaining stiffness and reducing fore and aft flex. The Fourstroke features 100mm of travel and 429mm chainstays to make for some quick handling. The geometry errs on the steep side (67.5-degree head tube angle) to encourage fast climbing. It’s available in three different builds, as well as a frameset option.

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Trade your carbon hoops in for a set of Enve wheels

Photo: Enve

From now until December 31, you can get your hands on a set of Enve wheels more easily than ever before. If you’ve got a set of carbon wheels at home that are rideable, you can trade them in and Enve will give you a credit toward a new set of SES, M Series, or G Series wheels. If you’ve got Enve wheels to trade in, you’ll get $1,000; if you’ve got non-Enve hoops, you’ll get $700 toward the purchase of a new set. Simply bring your rideable carbon wheels to your local Enve dealer to trade your wheels in, or go to Enve’s website to initiate the trade-up. This is a short but awesome window in which to turn your older carbon wheels into cash.

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Starbucks is coming to Italy and bringing a Bianchi with it

Photo: Bianchi

Italians love their coffee, so perhaps opening a Starbucks in Milan seems like a bit of a stretch. But Starbucks is doing just that, with a little help from its Italian friends. In celebration of the grand opening of Starbucks Reserve Roastery in Milan, Bianchi Bicycles is releasing its Starbucks Reserve bicycle. The disc-brake-equipped, drop-bar bike is intended for commuting and adventure, and it has a custom color scheme to commemorate what is sure to be a controversial addition to Milan’s coffee scene. You’ll have to hop a plane to Italy if you want one, though: The Starbucks Reserve Bianchi is only available at the Milan store.

Assos S9 shorts focus on stability

Photo: Assos

Assos of Switzerland has long been known for its exceptional quality, and odd naming conventions. It seems the company has discovered brevity with its simply-named S9 shorts, which feature a total redesign focused on keeping the shorts in place. The rollBar feature helps improve lateral stability to prevent bunching as your hips and legs move side to side. (This feature is eliminated on the RSR version of the shorts to help reduce weight for all you weight-weenie racers.) And the A-Lock Engineering system, which is a fancy name for the panel layout, helps keep the chamois from creeping and shifting underneath you. The bib straps cross over in the back for even more stability and comfort.

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Goodyear’s sub-zero tire sealant

To go along with its line of bicycle tires launched in April, Goodyear now offers a bicycle tire sealant that will work in temperatures down to -30°F. The sealant will be available late-September in 150ml bottles, which it says is enough for two 29×2.6″ tires or four 700x25mm road tires. It also claims the sealant can fix holes up to 6mm in size. While sealant isn’t the most glamorous bike product, this recent video of Goodyear athlete Geoff Gulevich offers a bit of excitement:

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Are broken chains a thing of the past?

Breaking a chain can ruin your day. Your crotch clonks onto the top tube and your foot hits the ground. My only broken chains have come on the mountain bike, and only during front shifting under load, which can pry a chain plate off of its pin. How likely are you to break a chain from the sheer force of a pedal stroke? I traveled to Germany to find out.

When riding a road bike with a derailleur, broken chains from simple pedaling load are actually quite rare. In the 1970s and 1980s, broken chains usually were caused by faulty maintenance, since you simply pushed a rivet in and out. Chain plates on derailleur chains used to be like those on track chains — they were flat with two straight holes. The pins protruded quite far.

The advent of 9- and 10-speed chains brought the need for special connecting pins due to the minimal protrusion of the pins from the plates; 5- and 6-speed chains were about 8 millimeters wide, and 7- and 8-speed chains were around 7.3 millimeters wide. Today, 11-speed chains are 5.6 millimeters wide (5.25 millimeters for 12 speeds). The pins of 11- and 12-speed chains are very nearly or completely flush with the face of the chain plate; this is accomplished by chamfering the edges of the pin holes and mushrooming out the heads of the pins into these recesses in the faces of the plates.

Has the strength of chains been sacrificed as they have become narrower to accommodate more gears? This question is not new. On stage 4 of the 2001 Giro d’Italia, the chain of featherweight Mexican climber Julio Perez (Panaria), who had attacked on the climb to the Montevergine di Mercogliano, snapped with only 4 kilometers to go. At the time, pundits wondered whether the failure was due to improper maintenance or ever-thinning chains. That debate arose again in 2008 when David Millar snapped his chain in the final meters of the Giro d’Italia’s stage 5.

Still, powerful sprinters like Marcel Kittel, Andre Greipel, and Peter Sagan regularly churn 1,500 watts through their 5.6-millimeter wide, 11-speed chains without failure. As it turns out, the European ISO standard of 8,000 Newtons of minimum breaking force for a chain offers a good margin of security.

The chains I tested in Germany all performed far beyond that barrier without breaking. Great success, right? Well, during the testing process, I noticed a separate phenomenon. The chains stretched some before breaking. So I decided to investigate further.

About the testing facility

I toured the Wippermann chain factory years ago and ogled at its huge chain-production and heat-treating capacity. I also was enthralled by its chain testing equipment, including the durability-testing machine that upholds the company’s claim of producing the longest lasting chains. I traveled back to Wippermann this June to test 11-speed chains, and to perform tensile-strength tests on other chains.

The 125-year-old, privately held chain manufacturer is in its fifth generation of the Wippermann family. In addition to making Connex chains for all types of bicycles, including e-bikes and track bikes, and chains for other vehicles, Wippermann produces industrial roller chains and fat, multi-plate “leaf” chains that lift the forks on forklifts and shipping containers onto tall cargo ships.

Wippermann manufactures in Germany, where labor costs are high, some of the world’s most stringent environmental regulations and restrictive building codes apply, and a high tax structure supports a social welfare and health care system that takes care of everybody. The factory is located in a lush, green valley in Hagen, in the Ruhrgebiet of west-central Germany. It uses a lot of water and detergent to clean off all of the oil required in the process of stamping and rolling and shaping all of its steel chain parts, yet when that water leaves the factory, it is certified as drinking-water quality.

In-house, Wippermann continually tests its chains as well as those of competitors with a wide variety of testing infrastructure. An enormous 100-ton tensile-strength-testing machine tests foot-long chains for failure; enormous chunks of metal fly when the links break. Another long-running machine continually tests a chain’s durability. Staff also examine the chains under microscopes. The tests are important — a broken bicycle chain can lead to a dangerous crash, and a broken industrial chain can cause unfathomable destruction. Before each chain is packaged, a machine tugs it with a load of 2.5 metric tons, and cameras inspect every link for defects. Wippermann guarantees each chain will last 15,000 hours, a staggering figure relative to what we bike riders expect to get out of bicycle chains.

Photo courtesy Wipperman

Breaking-load test

For this test, we used 14 different chains, which were cut into five, 13-link pieces.

With a pin through the chain’s end hole holding it in place, the ends were mounted into the upper and lower heads of a Shimadzu tensile-strength-testing machine (above).

The two heads of the machine slowly moved apart, producing a graph of pulling force versus extension in millimeters.

When the chain broke, the machine automatically stopped.

The results above show that all samples of the 14 chains went well over the 8,000-Newton ISO breaking-force resistance standard; in fact, all of them tested beyond 9,100 Newtons before breaking. Wippermann’s internal standard is 9,500-11,000 Newtons of breaking force for its bicycle chains, and they achieved that; some of the others fell short of that.

For reference, compare the minimum measured breaking load to that applied by a 198-pound (90-kilogram) rider standing on the pedal attached to a 175-millimeter crank at the 3 o’clock position. The highest chain load is with the smallest chainring: a 22-tooth on a mountain bike triple crankset, which has a radius of 1.76 inches (45 millimeters). To calculate chain load, think of a teeter-totter with its fulcrum 175 millimeters from the end the load is applied, and 45 millimeters from the end that the force is transferred to.

The force on the pedal is 90kg x 9.8m/s2 (rider mass times the acceleration of gravity). The load on the chain is then that force times 0.175 meters (the crank length) divided by 0.045 meters (the radius of the 22-tooth chainring), or 3,500 Newtons, which is well below the 9,100 Newtons that all of the chains withstood.

With the same crank and pedaling load with larger chainrings, the peak chain load is only 2,283 Newtons with a 34-tooth chainring and 1,472 Newtons with a 53-tooth chainring. Peak forces for road pros are in the 3,000- 4,000 Newton range. Even a 300-pound rider standing on a 200-millimeter crank with the chain on a 22-tooth chainring is only applying 6,044 Newtons on the chain, still well below the ISO standard of 8,000 Newtons and more than 50 percent below the 9,100 Newtons that all of these chains exceeded.

These results show that, with a properly assembled chain, Kittel, Greipel, and Sagan need not worry about their chains breaking in a sprint. If they were using a 53-tooth chainring, they would have to stomp on the pedal with 5,564 Newtons of force to reach the 9,100 Newton load on the chain. This is equivalent to a 1,252-pound Kodiak bear standing with all of its weight on the pedal!

On chains without link cutouts, breakage occurred at the end of an outer link; the outer link either broke at the hole or pried off of the pin. On chains with cutouts, breakage occurred at the middle of a link, right across the cutout. Nonetheless, the chains with cutouts (KMC X11SL Silver and KMC X11SL Gold) all withstood at least 9,535 Newtons of load before breaking.

After our test, I watched some Wippermann industrial multi-plate leaf chains being broken on a much bigger test machine. I watched one withstand 917,000 Newtons of pull before breaking — 100 times as much as bicycle chains can take. You should have heard the noise it made when it broke.

Chain elasticity test

I noticed during the breaking-load test that the chains tended to elongate by at least 6 millimeters before breaking, with those with cutouts in the chain plates elongating considerably longer than those with solid plates. I set about quantifying the elasticity of these two types of 11-speed chains.

Using the same Shimadzu tensile- strength-testing machine, three lengths of chain were gradually pulled 100 times with 6,000 Newtons of force. This is a force approximately equal to what a world-class kilo rider applies on the first couple of strokes from the start. This is a much higher load than road riders are ever likely to apply to the chain. After each tug on the chain, it was allowed to relax with zero Newtons of force pulling on it before being pulled on again.

One chain had solid link plates, while the other two chains both had cutouts in the inner and outer link plates. Each chain section was 31 links long, with an inner link on either end to engage the Shimadzu machine’s jaws. As bicycle chains have a 1/2-inch pitch, each link is 12.7 millimeters long, giving a calculated length of 393.7 millimeters, approximately equal to the chainring-to-cog length on a road bike with a short rear end.

After settling in following 10 or so pulls, the solid chain stretched up and down over an approximate range of 3.5 millimeters, while both chains with cutouts stretched up and down over an approximate range of 4.7 millimeters. Clearly, all of us are constantly stretching our chains on every pedal stroke, and if we have chains with cutouts, they are stretching a bit more.

If the chain behaves like a perfect spring with no energy lost as heat, then all of the energy is returned to the system. It’s returned, however, in a way that provides no additional power. In other words, the chain stretches when the chain is fully loaded on the pedal downstroke and stores this as elastic potential energy. Then, when the pressure reduces with the feet at the top and bottom of the pedal stroke, the chain contracts back in length. The chain’s contraction pulls the cog forward, but the equal and opposite reaction at its other end is to pull back on the chainring, slowing the passage of the feet over the top and bottom of the stroke. And by stretching on the downstroke, the chain allows the foot to drop down through the power stroke slightly faster.

If the chain were as stretchy as a rubber band, the bike would obviously get nearly nowhere; the foot would fall very quickly through the downstroke and transfer minimal power. Clearly, less chain stretch is more efficient than more chain stretch.

A brief physics lesson

We can quantify the worst-case scenario, where all of the potential energy stored in the stretched chain is lost when it relaxes.

Then, Hooke’s Law says that F = -kx and PE = 1/2kx2, where k is the spring constant for the chain, x is the amount of stretch, F is the force to stretch it, and PE is the potential energy stored in the chain. Ignoring the negative (which indicates directionality), the spring constant for the no-cutout chain is:

k = F/x = 6000N / 3.5mm = 1,700,000 N/m (no cutouts)

Similarly, the spring constant for the chain with cutouts is:

k = F/x = 6000 N / 4.7mm = 1,300,000 N/m (with cutouts)

Now that we have the spring constant for each chain (and assuming it is indeed a constant for a bicycle chain, which I’m not sure is the case), we can use it to estimate the chain stretch under different loads. We saw above that the peak chain load for a 198-pound rider simply standing on the pedal of a 175mm crank with a 34-tooth chainring is 2,283 Newtons. So, the displacement for the no-cutout chain at that load is:

x = F/k = 2283N / 1,700,000 N/m = 0.0013m = 1.3mm (no cutouts)

And the displacement for the chain with cutouts at the same load is:

x = F/k = 2283N / 1,300,000 N/m = 0.0018m = 1.8mm (with cutouts)

Then the potential energy stored in the no-cutout chain when it is stretched under that 198-pound load on the pedal is:

PE = 1/2kx2 = (1,700,000 N/m) (0.0013m)(0.0013m) / 2 = 1.4 Joules (no cutouts)

And the potential energy stored in the chain with cutouts when under that same load is:

PE = 1/2kx2 = (1,300,000 N/m) (0.0018m)(0.0018m) / 2 = 2.1 Joules (with cutouts)

If all of that energy is lost, then the power loss is equal to the energy lost in chain stretch on each downstroke divided by the time for each downstroke. There are two downstrokes per revolution of the pedals, and there are 60 seconds per minute, so if the rider is pedaling at 100RPM with that same peak load on the pedal each revolution, then the power lost in the no-cutout chain is:

P = 2*(100/min)(1.4 J) /60s/min) = 4.8 watts (no cutouts)

And power loss for the chain with cutouts is:

P = 2*(100/min)(2.1 J)/60s/min) = 7 watts (with cutouts)

The bottom line on chain stretch

So, in this worst-case scenario, where none of the potential energy of the stretched chain is recovered as forward motion, the chain with cutouts consumes 2.2 more watts of power than the chain without cutouts.

That extra little stretch of the cutout chain costs something each pedal stroke, while its 30-gram weight reduction (at most) gives something back when climbing or accelerating. But how do these compare? That 90-kilogram rider is putting out at least 500 watts if he puts his full body weight on the pedals with each stroke, and plugging those numbers into, it would take him 3.12 minutes to ride a 9-kilogram bike up an 8-percent climb for a kilometer. If that rider’s bike weight dropped by the 30-gram weight savings of a chain with cutouts while his power dropped by 2.2 watts — the extra energy losses in the cutout chain versus one without cutouts — that same climb would now take 3.13 minutes, or 0.6 seconds longer. Not much. The difference would probably still be tiny if you changed the variables — the length of the climb, the weight of the rider, and so forth — to more realistic values.

Additionally, one might argue that when the chain stretches it is not perfectly engaging the last couple of teeth leaving the top of the chainring and the first couple of teeth entering the top of the cog, thus resulting in a slight increase in frictional drag. This would be hard to quantify.

In conclusion, all of the brand-name chains we tested offered a good margin of safety against breakage by sheer force. And there is no such thing as a free lunch; sometimes weight loss will cost you more in flex than it provides in the way of reduced power required to drag it up a hill.

Read the full article at Are broken chains a thing of the past? on