Slim is a unique fender that stores your U-lock which then serves as your rack. Due to the U-lock’s specific sizing, for now, Slim only works with the Kryptonite Keeper 12LS (sold separately, find it here).
Slim mounts to the brake bridge, as well as further up the seat stays with the supplied clamping brackets. So Slim does not work on bikes that have rear caliper brakes that are already using that brake bridge. Slim is great for bikes with coaster brakes, drum brakes, or disc brakes, and its simple, clean lines will look especially good on your fixie.
Slim comes in 3 sizes based on the angle of your seat stays, and can be micro adjusted to level with the supplied extra washers. Generally, Slim works best with road bike frames with a fairly level top tube. Mountain bikes + bikes with sloping top tubes tend to have seat stays with a lower slope, and Slim won’t be able to mount on these bikes with a balanced, level look. To check the angle of your seat stays, you can download the free iPhone app “iHandy Level Free” and set your phone right on your seat stays. If your stays are between about 49° and 63° from level, you are in luck. Choose the size below that is within 2° or 3° of your stay angle...
Small: 51° Medium: 56° Large: 61°
Once you have the correct size, test fit Slim with the supplied hardware to see if the tail end is level. Add washers between Slim and the brake bridge if you need to raise the tail a bit, or between Slim and the upper mounting bracket if you need to lower the tail.
Contact us at Ruphus if you have any questions. Enjoy Slim and make nice!