Originally Posted by
DorkDisk
However, realize that V brakes were a bigger game changer than disk brakes were. When Vs appeared, cantilevers instantly disappeared from all MTBs, it took disks about 15 years to take over MTBs.
I think the primary reasons linear pull brakes took over almost immediately are:
- Cost; it costs less to build a bike with linear pull brakes (compared with cantilevers) because they're easier to setup and require fewer parts (no straddle cable, etc). Shimano's staddle cable simplified setup of cantilevers, but also worsened the performance of the brakes in many cases. Linear pull brakes cured all of that, and they were cheaper, too!
- Compatibility and standardization; no frame changes were required -- they were designed to work with standard cantilever mounts, so design changes to the frame could be avoided. They didn't even need different hubs; all they needed were long-pull brake levers (which are interchangeable, from a cost perspective, with short-pull brake levers). They were literally bolt-on parts using the then-standard design (cantilevers), which had been standardized across the industry for three or four decades or more at the time.
Disc brakes, of course, required more fundamental changes. You now needed a fork and frame with disc mounts, and hubs. What's our standard? In the beginning, we didn't really have one. We had the "International Standard" that wasn't adopted across the board, with its 51mm tabs. One problem with IS is the lateral distance from the caliper to the rotor was different for front vs. rear, meaning different adapters or calipers were required. There were also other proprietary standards, like Hayes and Manitou. The 74mm Post Mount has become the de facto standard for disc brakes as of late, and the reference design is 160mm front and rear, which is pretty common today. But just wait -- there's a relatively new player in town, and it's another proprietary standard: the Shimano Flat Mount. I think the reference design with Flat Mount is back to 160mm front/140mm rear, like IS, but I'm not sure on that.
I think it's fair to say that disc brakes have completely disrupted the cycling industry, from design considerations (all of the various standards) to regulatory considerations (what will be allowed in racing). Linear pull brakes, such as Shimano's V-brake, were an evolutionary design from the already-standard cantilever, making its adoption cheap and fast.