Hi All, this is an information post to help any poor soul trying to work out the new flat mount standards that work on the 2019 Salsa Waxwing fork (3 anything cage bolts, 12mm axle, 100mm spacing). After both myself, and a good friend googled the hell out of this, it took a lot of fathoming, and a bit of trial and error.

After doing what I though was enough due diligence, I saw that this fork was described by Salsa as a 'Flat Mount'. I have SRAM Post Mount calipers and ordered Flat Mount to Post Mount FRONT 160mm. Frameset and adaptor turn up and what d'ya know, it doesn't fit. The bolts are 70mm apart on a FRONT Flat mount...and this forks are 35mm.

The fork turns out is a REAR Flat Mount standard (Only reading through certain Salsa framesets frame specs can you see this mentioned, not the vaya), which natively fits a 160mm disc on this front. If using Front Mount calipers there would be no need to add a spacer here for the max recommended 160mm rotor.

For conversion to Post Mount caliper, a REAR FM to PM adaptor 140mm disc fits a 160mm rotor on the Waxwing fork.

SRAM doesnt make any adaptors from FM to PM (trying to sell new brakes I guess) so Shimano or TRP are your options.

Summary:

SM-MA-FxxxP/D - doesn't work on the flat mount on this fork which is the REAR standard.

SM-MA-R140P/D - will see you fit a post mount caliper with a 160mm rotor

SM-MA-R160P/D - will see a 180mm rotor on the fork (which seems is past the specified dimension for this fork)

Happy cycling!