Disc brake mounts
One of the key differences between the U.P. and U.P.P.E.R. is the disc mount standard. The U.P. uses post-mount, whereas the U.P.P.E.R. is designed for flat-mount. We don't like how the bike industry keeps “inventing” new standards, so we always investigate if they are an improvement before we use them.
Post-mount brake calipers work very well, and the main argument for flat-mount is that it looks better (sigh) while a significant drawback is that the front brake always requires an adapter for mounting, adding weight and reducing braking efficiency.
So why did we decide to offer the U.P.P.E.R. with flatmounts? Three reasons:
|1.||Shimano has decided to make the new DuraAce group only available for flat-mount. So to use their top group, you need a flat-mount frame or an adapter to fit post-mount brakes on a flat-mount frame.
|2.||SRAM does offer all its brakes in flat-mount and post-mount versions, but the flat-mount calipers are lighter.
|3.||We designed the U-turn, a new fork that accepts flat-mount calipers without the need for that silly adapter. So that disadvantage is eliminated for OPEN.
In conclusion, to use the lightest possible brakes from both Shimano and SRAM, you need their flat-mount brakes. And thanks to the U-turn fork, you can make those set-ups even lighter by removing the normally required adapter. A win-win.
The disadvantage is that you cannot spec the U.P.P.E.R. with post-mount brakes, so for example the exotic combination of using XTR mountain bike brakes on the U.P. is not possible on the U.P.P.E.R.
One more way we have squeezed some weight out of the U.P.P.E.R.: while the new U-turn fork is set up for 160mm rotors up-front, the frame will accept 140mm rotors in the rear. Since it’s the front disc that is the limiting factor in braking, this combination of bigger up-front and smaller in the rear makes a lot of sense and saves 10-20 grams depending on the brand of rotor. If you really want to use 160mm discs in the rear of your U.P.P.E.R., then Shimano and SRAM flat-mount brakes also offers that option with their dedicated adapter (but as you know by now, we’re not big fans of adapters).