Bearing longevity is critical in the elite cycling industry, particularly for the bottom bracket bearing, the most punished part of a bicycle. A pro rider can wear out a bottom bracket bearing as quickly as every two weeks.
“I wanted to find something that lasts a really long time so I can ride my bike farther and longer without having to change out the bearings.” –Matt Harvey, Co-founder, Enduro Bearings
Enduro Bearings co-founder Matt Harvey, an avid biker himself, was well aware of the shortcomings of existing bearing technologies. He knew that there must be a way to build a superior bearing for pro cyclists, helping them ride farther and longer.
Matt investigated different ways to improve the 52100 bearing steel he used, including heat treatments, cryogenic treatment, and more. But it was only when he shifted his thinking, looking to other industries, that he came upon a material with the ideal properties.
He discovered nitrogen alloys—specialized steel used in the aerospace industry for flight-critical components. Nitrogen grades offer superior wear resistance, hardness, and corrosion resistance. Matt figured that if any material could withstand the rigors of high-performance racing, nitrogen steel was it.
Securing the steel, however, proved challenging. When the mills wouldn’t return his calls, Matt was stuck spinning his wheels.
Then, a chance meeting at a trade show with Todd Chavanne, Business Development at Sullivan Steel, changed all that.
Sullivan Steel specializes in providing high-performance steel grades for demanding applications. Client industries range from aerospace to motorsports to food & beverage production to medical equipment.
After a conversation with Matt about his goals for bearing performance, Todd suggested one of Sullivan’s offerings—XD15NW, a martensitic nitrogen steel made by French mill Aubert & Duval.
Now that Matt had a knowledgeable supplier of aerospace-grade steel, Enduro geared up to prove the alloy’s feasibility for hybrid bottom bracket bearings.
“It was unknown territory, definitely for the cycling industry at the time, because nobody was using the material.”
Enduro got the ball rolling and created a prototype of what would become the XD15 bearing (named for XD15NW). For Matt, working with a new grade was intimidating, but Sullivan provided technical support for every step of processing.
Finding the best heat treatment procedure was a unique challenge. Todd reviewed the technical results after every heat-treat iteration, tweaking the procedure until Enduro reached a point where bearing races came out as close to finished as possible.
Matt supplied several cyclo-cross riders with his new XD15 bottom bracket bearings. The punishing terrain and conditions of cyclo-cross races were ideal for evaluating the performance of the XD15.
Enduro also carried out lab testing of XD15 bearings against conventional industry bearings. An amplified testing method shortened the test period from years to just a few months.
The test rig measured three variables for each bearing:
The cyclo-cross riders experienced impressive results from their XD15 bearings right out of the gate. After months of riding through sand and dirt, the XD15 performed like new, even in the notorious Sand City race—it was an unheard-of result for a bottom bracket bearing.
In addition to resisting damage from particulates, field testing also proved the XD15’s corrosion resistance when, during an early-season race, roads were salted due to an unexpected snowfall. Corrosion destroyed every bearing on every bike in the race except for the XD15s, which not only survived but were seemingly unaffected by the highly corrosive road salt.
“I knew already the XD15 worked because of the field testing. But it’s always good to be able to replicate the results in lab testing, too.”
The XD15 lab test results told a similar story to the field tests:
One of the most surprising results of the field testing was that XD15 bearings did not require any maintenance at all, even without grease. When particulates infiltrated the XD15, rather than causing deterioration, they seemed to polish the races smoother.
“XD15NW was the silver bullet answer I was looking for, because nobody has problems with these things once they have them. And they don’t need to service them, just put them in your bike and ride. I’ve seen bikes 10 years later with XD15 bottom brackets still going.”
Since Enduro released the XD15 bottom bracket bearing, it’s gained an industry-best reputation for high-performance cycling. In the harshest racing conditions, the XD15 bottom bracket bearing continues to function, even becoming smoother over time. Today, it still sits at the pinnacle of performance with millions of units sold worldwide to hundreds of OEMs and distributors.
Enduro achieved its goal of innovating a bottom bracket bearing that allows cyclists to ride longer, farther, and harder with no bearing maintenance whatsoever. The lifetime guarantee for XD15 bottom bracket bearings is an industry first, and proof of Enduro’s confidence in the reliability and durability of Aubert & Duval’s XD15NW steel.
“I don’t think we could have gotten the XD15 across the finish line without Sullivan sticking with us. If there had been nobody to talk to and get advice on next steps, we probably would have stopped, and that would have been a terrible shame for the cycling industry.”