right ive always thought i have to go up a disc size if i want my is caliper on a post mount fork. But ive found a mount that allows me to fit a 160 is caliper to fork and run a 160mm rotor. Problem is my m4 caliper is a 180mm caliper. But as this just bolts to a standard is mount without adaptors size must be to do with the angles so will my caliper work in a 160 to 160 adaptor and keep same rotor do we think . Ta 🙂

Which adaptor is that?

its a kcnc made adaptor cant do a link as dunno how to on phone 🙂 if you google the adaptor and clee cycles its there

I will be surprised if it does, as post mount M4 calipers won't work on 160mm rotors. I have just looked at that mount, and I think your problem will be the caliper will hit the middle of it, I could be wrong?

well its a 180 caliper and i want to use a 180 rotor i guess im meaning are the holes in a 160 adaptor the same place as the holes in the 180 caliper. If so it might just work

ah not thought of that 🙁 bugger lol

Surely the holes would be in the same place as an IS fork, so it would still work with 180 disc, or am I missing something?

that was what i thought but jason mentioned it may interfere with caliper i will have a look tomorrow at my brakes thinking it may well work tho 🙂

Sorry I miss read your post, I thought you were trying to run with a 160mm rotor. As it is a 180mm rotor, I guess it will be fine. So ignore everything I have written above 😳