Rear flat mount help
 

Hey guys, just got a new frame today, a Niner RLT steel, and some adapters to mount the brakes with 160mm rotors. The rear adapter's bolts, however, are not long enough to make it through the flat mount... mount in the back. Has anyone come across this in the past? Are there longer bolts to be obtained or am I missing something?

Yes, there are longer bolts. Shimano makes several lengths. The exact bolt you need depends on your model caliper. Different caliper models take different bolts. What model caliper are you using?

Part numbers for each length are in the exploded view document for your model caliper at Manuals & Technical Documents.

Worldwide Cyclery has large selection of caliper bolts. Find the correct Shimano part number for the length you need in the EV diagram for your caliper and search the Worldwide Cyclery website for that part number. Chances are they will have it. I purchased a couple extra and glad I did because I stripped one. Actually I stripped the adapter but didn't trust reusing the bolt.

This is a photo of my Niner RLT 9 RDO build. I'm using RS805 calipers. You can see the two different length bolts. I needed longer ones for the exact reason you do - the calipers come with bolts for 140 mm rotors but I built with 160 mm rotos and used the spacer under the rear caliper.

See post number 64 at https://www.bikeforums.net/cyclocros...o-build-3.html

https://cimg6.ibsrv.net/gimg/bikefor...889c3da6eb.jpg


-Tim-

Thanks! It is the adapter I can't thread into (it is flat frame to post caliper). The portion of the frame to go through is 30mm, and the bolts are also 30mm, so that explains it, they are just what came with the adapter. Why couldn't we just stick to post mount...? But that settles it. Appreciate the help!