So, flat mount. It’s the new hotness in performance bicycle braking systems, revolutionising caliper mounting through an all new updated interface, offering 1000% improved braking and 2000% more aerodynamic efficiency. Or something like that.
In actual fact, flat mounts are just another way to bolt a brake to a bike. I’m not convinced it makes much difference, but I am but the tiniest of minnows in the great polluted ocean of cycling, trying not to get eaten alive by the Big Sharks from Osaka, or poisoned by some toxic innovation from California. To my way of looking at things, there are two key problems with the flat mount design, both fundamentally due to the primary reason the standard was developed: to make the fabrication of carbon fibre bikes simpler.
The issues I have with the flat mount standard:
– the result of the geometry of the brake mount means that, on a steel bike, mitring the bosses onto the chainstay results in fully three quarters of the tube having to be cut away for one of the bosses. That strikes me as kind of insane in such a highly stressed area of the bike.
– On the fork, they need relatively small M5 threads right down by the axle, and, often, holes (holes!) right by the dropout at a highly stressed part of fork.
So the options for rear dropouts and mounts, are either to notch out big sections of the chainstay, or use really long flat plate dropouts, which I think are pretty ugly. I’ve always been a big fan of cowled dropouts, and I can’t get past the looks and tube compromises of the long plate dropouts.
I didn’t like either of those options, so I’ve gone my own way, designing my own twin plate flat mount setup. Made as a little subassembly, I can ensure that the bosses are exactly right every time, even with my simple tooling, and no savage tube dismembering is required. From now on, accepting the pull of the oceanic currents of the the bike industry, all my Carriers, and any drop bar custom bikes will use this new dropout.
Up front, I’m continuing the tradition of the “Willets” style IS disk mount, by including a sweeping brace up the fork leg for the front dropouts. This can be done on straight and raked forks. The mounts are pushed out so the fork blade doesn’t need any holes drilling into it.
I’m proud of these designs, and I feel like they show my approach to this whole bike building thing.