Because safety is a big concern for bike riders, it is also important to bike manufacturers. This is the case for BMC Switzerland AG, which has designed and built road, mountain and commuter bikes since 1986. Stefan Christ, head of development at BMC, notes the important role that fasteners play in building a durable and safe bike, regardless of model and whether the cyclist is a casual rider or a serious professional.
“Fasteners are critical points in the bike structure and can strongly affect [its] safety when [in] use, [but] bolts are often the components which we find [the] hardest nut to crack,” explains Christ. “[Based on] internal and external stress tests, it is the bolts [that] often cannot withstand extreme loads.”
To solve this problem, BMC engineers worked closely with Bossard Technical Center in Taiwan several years ago to develop a new bolt with a built-in safety function. The fasteners that BMC had been using until then proved to be inadequate.
Bossard developed the ecosyn-grip bolt fairly quickly, producing a fastener that resists vibration and material fatigue, while also meeting the EN14766 standard for mountain bikes. The standard includes safety specifications and details the corresponding test methods.
One test, for example, focuses on the endurance of the handlebar and stem, which must be able to withstand 200,000 cycles. Bossard followed the standard when performing various tests on the bolt, before carrying out a detailed analysis of its mechanical properties and behavior under vibration.
Test data reveals the bolt offers high anti-vibration capability and high fatigue strength. Equally important, the bolt is economical to produce. For these reasons, the ecosyn-grip bolt earned Bossard the Taipei Cycle Design & Innovation Award.
BMC followed Bossard’s test with an endurance test of its own to see how the bolt performed under harsh conditions over the course of one month. The manufacturer installed the bolt in a pedal that was rotated more than 4 million times at a high vibration in harsh environmental conditions.
Christ says the bolt performed flawlessly, proving the bolt’s quality and reliability. Testing was then repeated in an independent SGS lab in Switzerland, with the same results.
The key to the ecosyn-grip bolt’s effectiveness is its unique design. Instead of having a washer, the bolt features a recess at the transition of the shaft to the head. This design increases load-bearing capacity and reduces the risk of the bolt loosening and falling out.
Christ says BMC likes that the bolt lessens the number of fasteners and washers needed for each bike assembly, resulting in lower material costs and higher productivity. But, what the company likes even more is how the bolt increases cyclist safety while easily working into BMC’s bike designs.
“Generally, the bolts must be coated black to match the uniform quality look and feel of a BMC [bike],” says Christ. “[The bike] should stand out from the crowd, even without color and logos. This requirement poses a further challenge to the engineer looking for the ideal [fastener].”
For more information on specialty bolts, call 41-41-749-6611 or visit www.bossard.com.
