Flat Mount fixture
NOTE: Incepi tool geometry is based on official Shimano location geometry only.
Incepi Flat Mount 160mm and 180mm locations are not derived from reverse engineered adapters and calipers. They are not taken from unofficial websites or blogs. There are significant differences between the official Shimano location geometry and the geometry used by some other tool providers. The variation is well beyond the tolerances required by Shimano. This difference could cause brake calipers to be mounted outside of Shimano location tolerances.
Update: May 2020. A precision adapter plate has been developed for 160mm and 180mm rotor locations for both frames and forks. It is a simple and economical design. Descriptions are available on the Instagram page @incepibicycle.
This Flat Mount jig can be used to attach Flat Mount caliper mounts to any bicycle frame or fork. The fixture requires a 3/4"(0.750") dummy axle. A 20mm dummy axle option is available upon request. The design geometry is for 140mm or 160mm rotors. The fixture has 140mm written on it because 140mm is the base location for all Shimano or SRAM Flat Mount calipers. If you are building for either 140mm or 160mm rotors this is the correct fixture.
The fixture uses a small mounting block for frames. A simple plate attachment is available for forks. The frame block has two pairs of raised features which lock into the caliper mounting slots, keeping them parallel and preventing rotation during welding or brazing. The features are 34mm apart, and in the correct position relative to the axle as per bicycle industry standards. Any standard Flat Mount caliper mounts may be used. They may be purchased from Paragon Machine Works, other suppliers, or made by the framebuilder. The fixture is sold with the frame block as standard. The fork plate may be purchased separately.