After our first outings on the new Bontrager Line Pro wheels we reached out with a few questions to learn a bit more about the offerings and development.
TLW: Could you explain your Carbon Care Wheel Loyalty Program?
Bontrager: If you damage a Bontrager carbon wheel while riding within the first two years of ownership, we will replace or repair it for free*. It’s that simple. This coverage applies to Bontrager carbon wheels that come stock on bikes as well as aftermarket wheel purchases.
They also come with a 30-Day Unconditional Guarantee. If for any reason you’re not satisfied with a Bontrager aftermarket purchase, return the item, along with the original sales receipt to the original place of purchase within 30 days for an exchange or refund. Think of it as a 30-day test ride.
TLW: Was there a major catalyst that started the new Line wheel development or just the quest to always improve your products?
Graham Wilhelm – Director of Product – Wheels and Tires: We are always looking for ways to improve our products in order to deliver the best experience for our customers. The reality is that as bikes get better, more people are riding harder, and faster. Riders are carrying more speed through rough, rocky sections, spending more time in parks, and getting away with poor line choices – and the wheels are taking all of that abuse. We wanted a better, stronger product that could keep pace with bigger, better bikes.
TLW: What were 3 of the most important factors for the new Line Pro wheels?
GW: Hook shape: We designed the hooks to be ~4.6mm thick; that’s almost 2mm thicker than the previous design- This make the rims a lot stronger against square edge impacts that are the big enemy of carbon rims.
A great side benefit of the thicker hook design is we could put a large outer radius on the hook and that really helps reduce pinch flats.
Manufacturing method: We use an OCLV process on our rims that allows for optimum molding of the complete rim section including the hooks. I can’t get into the exact details on our manufacturing method but if you section one of our rims you would be hard pressed to find any voids in the carbon layers that make up the hooks. If you section some other brands rims you will likely find voids in the hooks and those voids can lead to inconsistent strength around the circumference of the rim. Our process also ensures that the materials stay in the right place when molded and not flash out or move to create inconsistencies.
Material: For the Line wheels, our OCLV carbon relies on a resin system that is optimized for impact.
TLW: What sort of lab tests make Bontrager so confident in your strength claims about the wheels?
GW: We started with a standard impact test as we wanted to be able to compare with past test results. We also developed a new impact test head to better simulate field failures we were seeing with warranty and carbon care returns. The new impact head looks like a guillotine and is pretty abusive to the rims. The new rim is 4 to 5 times stronger in this new test. This testing is fun, we get to smash stuff, but the real benefit is what we learn from each design and how it behaves when impacted. This testing has helped us build better, stronger rims. The new Line wheels are actually the strongest wheels we’ve ever produced, and also the strongest we’ve ever tested, of any brand.
TLW: After lab testing was complete, we imagine you sent the wheels out for some real-world R&D. Were there any key athletes or riders involved in this project?
GW: Yes, we have designated test riders we’ve been using for quite a while and not only are they talented riders, but they are very knowledgeable and provide great feedback. For controlled tests we used Ely Woody, Zach Graveson, Brad Jalolen and myself (no talent but I like to show up and pretend, ha). For general miles on these wheels we used the controlled test crew in addition to employees from both our SoCal and Waterloo office, Travis Brown’s Durango crew, Charlie Harrison, Pedro Burns, and some of the C3 guys as well – Cam McCaul, Casey brown, and R-Dog. These wheels were also heavily used on Trek trail bike test mules.
TLW: What sort of feedback was given off the bat, were major changes requested along the way?
GW: The feedback we received off the bat was pretty good. Riders were really impressed with the abuse they were able to take. A lot of that strength came from designs that were tested and tweaked from our in-house testing. But rider feedback helped validate it and drive tweaks on the layup and overall build, such as spoke spec to improve impact performance, wheel stiffness, and overall ride feel.
TLW: How vital is having professional rider’s input when developing a product?
GW: It depends on the product. For wheels and tires that will be on a professional’s bike during race day it’s critical we have their input in the process and we perform controlled tests with these athletes. For product that they don’t race we will use them just to put hard, abusive miles on them such as Charlie Harrison rocking these wheels on his trail bike and getting the C3 guys like Cam and R-Dog lapping them in parks or on their local trails. All that ride time and feedback really help validate all of the work we’ve put into them and ensure the final products will stand up in the field.
TLW: Will the wheels still be comfortable and compliant for riders who aren’t slam-banging berms and landing huge drops like R-Dog?
GW: Definitely, even though these rims were designed to take abuse, we targeted the overall wheel compliance to be similar to the previous wheels, as we’ve found this to be a good balance for trail bikes.