[jgys]

They also only work with frames that have been specially designed to allow fitting a belt, as I understand it. Chains can be easily broken and joined in the shop (or even on the roadside), but not so with belts, so the frame must come apart to get the belt going through the rear triangle, which substantially complicates frame building and design.

I don't mean to suggest this tradeoff isn't worthwhile to people who want clean, low-maintenance bicycle drivetrains for working or commuting, but the extra cost of manufacturing makes it harder to persuade cost-conscious consumers.

[top_sigrid]

This is true and a good point, but: It is hopefully only a matter of time until belts can also be joined and opened. Veers split belt [1] system already does this, hopefully this becomes more common, so the need for a belt specific bike-frame disappears.

- [1] https://www.veercycle.com/products/split-belt-pro

Edit: As pointed out in another comment, the fixed size of a belt remains though, unlike with a chain.

[usrusr]

These days you have Veer who offer a split belt that unlike the closed loop Gates belt can also be used with closed frames. But they still need to be manufactured to a specific length, unlike chains which are sold one size easily adjusted to all.