1

It is hard to prove non-existence, but as far as my research goes, there is no carbon frame available for belt drive systems like Gates. My guess is that this is due to the requirement to be able to open and close the frame during belt installation. However, at the same time, carbon frame manufacturers claim that they can tailor a frame's lateral & etc. stiffness by layer density, fibre orientation and the like. So my question is what is the exact reason why belt drive systems are not available on carbon frames?

...of course, I'd also be happy if my research turns out to be incomplete...

  • 6
    Have you tried Google? I can find one in the first hit for "belt drive carbon frame" – ojs Feb 2 '19 at 10:26
  • Any frame can be used with a drive belt like the Veer, which has a join in it. No idea how good they really are. – Criggie Feb 2 '19 at 12:04
  • @ojs: wow, I obviously always tried a wrong(?) sequence of words; with your recommendation, I've found single speed belt drive bikes, which also underlines what was answered: If your focus is weight, you go for carbon frames and light gear, or no gear at all, but not for internally geared hubs. – StefG Feb 3 '19 at 10:08
  • @Criggie txs for pointing me to another incompleteness of my research; this definitely sounds like an idea that I should discuss with my LBS! – StefG Feb 3 '19 at 13:52
  • @StefG - see Trek District Carbon – David Lapeš Jul 2 at 13:51
5

There is no reason a carbon fiber composite frame could not be built to accommodate a Gates drive. CFC can be bonded to a metal split dropout no problem.

CFC frames designed for Gates drives are likely not common because the frame materials and drives are intended for different niches. CFC frames are intended to be light, efficient and fast, are relatively expensive compared to other frame materials and are combined with derailleur drivetrains. Gates drives require internally geared hubs which are a bit heavy and are aimed at 'practical' cycling offering no mess and low maintenance, where CFC frames are not used as alloy frames are perfectly adequate.

| improve this answer | |
3

It is not the case that carbon frames are unavailable, but they are few and far between. There was the Trek District Carbon, but that was single speed. Apart from that the only Gates Belt compatible carbon frames I know of are made by http://olsenbicycles.com

| improve this answer | |
2

what is the exact reason why belt drive systems are not available on carbon frames?

In addition to the other answers that point out that there is no such reason, because the premise itself is false, I'll point out that while a split frame is a common way to accommodate a belt drive, it's by no means the only.

The other main approach for accommodating belt drive is to use an elevated chain stay, which allows the drive belt to pass entirely under the chain stay, rather than having to be routed through the triangle of the rear frame. This avoids having to split the frame at all. This is the approach taken by Olsen, mentioned in a different answer, as well as several other bike manufacturers who support belt drive configurations.

Reasons for lack of availability, to the extent that there even is less availability for carbon frames as compared to frames made of metal or other materials, are much more likely to relate to market conditions, i.e. that there's rather much less demand for belt drive in that market due to differences in the way the bike is expected to be used.

Belt drive trains are typically heavier than an equivalent chain drive train, and very often are chosen for riding in conditions where the use of the belt significantly reduces maintenance hassles (e.g. due to rainy or muddy conditions, such as for commuting or off-road). Both of these factors have a small (but certainly non-zero) intersection with the goals of riders who choose a carbon fiber frame.

There is no technical reason that a carbon frame couldn't be designed to accommodate a belt drive system, and indeed there are examples of both major design approaches in the carbon fiber frame market.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.