by BobbySweeting on Sun Dec 17, 2017 9:05 pm
This is a great discussion. I'm happy to throw in my 2 cents, or whatever it's worth, haha.
We embarked on this carbon clincher resin project, in part, to see if we could make a rim that would as durable under brake loads as a disc brake wheel. We got pretty darn close, I'd say. We wanted to do it because we're grumpy old road racers and personally prefer rim brakes on our own bikes. For me it comes down to user friendliness. It's just easier to take care of, easier to adjust the brakes, easier to swap wheels, etc etc. That's just why I enjoy them. As long as there is no risk of delamination and no issue with stopping power, I think rim brakes are great.
We make awesome disc brake wheels because I do see the benefits in them, especially in the mountains. Remember, I'm in Florida! And the more that the big frame manufacturers move towards disc brake models, the more we will move away from rim brake wheels. In that regard we simply have to follow what they are doing. But if I may, I have an opinion as to why disc brakes are being pushed by the large frame and wheel manufacturers, which has to do more with their bottom line.
Think about the use and required production protocol for disc brake wheels: no brake track (obviously) and no risk of brake rub at the rim. This means a few things. A manufacturer can use a very inexpensive resin, a lower modulus fiber, cheaper molding techniques (such as aluminum molds instead of steel), and can machine build the wheel instead of hand building them. This can all be done because it matters less if the wheel falls out of true, it matters less if there are interior wrinkles inside the rim, and it matters less if the wheel is softer overall. As long as it doesn't crack, it's all good. If your rim brake wheel isn't dialed, you'll notice straight away! But if your disc brake wheel has a hop in it because the spoke tensions aren't even to begin with, most people probably won't notice or care.
At Alto, I can say for certain that our rim brake and disc brake rims are made with the same methods and materials. But we aren't a huge company, so our bottom line is less important than our product quality. At a 50 million dollar company, I think the incentive to sell a wheel that has less warranty risk and significantly less production costs, regardless of user friendliness, would be very high. This is simply my opinion, I have no idea how any of the larger companies are actually producing their disc brake rims, but I can see how there would be opportunity there to cut costs.
Flrider: If you shoot me a message through the contact page of our website, I'd be happy to send to the 3D model of our disc brake rims (in STP or IGES file type). That way you can see exactly how they were designed and shaped. I'd have to remove some of the proprietary dimensions, but I can leave in the critical ones that you're interested in. After hearing your concerns, we may update the website to show the actual 3D model and the mold as a representation of the cross section, which may be something that you guys would prefer!
DJGarrett21: If you check out our test video, you will see that we are controlling the energy into each rim at 1200 Watts and allowing rim velocity to act as a dependent variable. This is done with a motor build out that included a torque meter, amp meter, and frequency modulator. The conductive properties of our resin are absolutely the most technologically advanced in the cycling industry. As far as our expertise goes, I do think that a small brand with multiple engineers and material scientists has the ability to develop something of this nature. I can appreciate your opinion because it was a significant undertaking and not something that came about overnight. It was about 8 months of R&D and a LOT of extra capital from our investors. Unfortunately the resin additives and the exact thermoset properties are a trade secret at the moment, and not something we're willing to disclose. Our intent was to show a very transparent test regarding its performance, so hopefully that will be enough to convince you!