what size disc brake rotor to get???

5-7HEAVEN said:

I bought one of those adaptors. Unfortunately, the smallest size (16mm) was still too big for my 12mm dropout. I guess I'll have to shim it a bunch.

Other than that, it fit well enough, and a 203mm disc will fit my 130mm wide frame.

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I bought the same adapter and have the same problem, I had to shim it. Luckily my after market kickstand seems to clamp the adapter nicely. Other then that it works great.

Why not just make or buy a 1/2" P-clamp instead of shimming it? 12mm is basically 1/2"...

mrfubs said:

thats a great idea for a different build an its cheap! how can you make that work with the sprocket already there?

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You will need a drive sprocket that is smaller then the brake rotor to use the caliper as intended. If your sprocket is bigger then the rotor and you can mount the rotor; you can take the brake caliper apart and use just half of it on the rotor. It works, not as good as a fully functional caliper, but it works. The only side effect of a one sided caliper is you'll go through brake pads more often.

My 6 hole sprocket is way larger then my rotor. For the rear that adapter needs a 180mm rotor. (160 on the front) I made a spacer on the lathe for the rotor to bolt to the rear hub through the sprocket and my setup works fine. Didn't have to take the caliper apart.

Thanks for the tip, F Rod81.