Building up my latest bike with a mix of new (frame, fork and wheels) with old (drivetrain, brakes, etc).
Nearly there and I've run into an issue. Trying to fit a Hope Mono M4 front brake (180mm caliper) to a Cane Creek Helm fork with post mount (180mm minimum rotor).
I've purchased the Hope adapter for this job but it spaces the caliper out by 20mm and I'd need to run a 220mm rotor < not happening! It's now in my spares box.
Ideally, I'd like one of these KCNC Disc Brake Adapters (Post Fork 160mm - IS Caliper 160mm) with 0mm offset, but very few online stores have stock.
https://clee-cycles.co.uk/P1043/product
So putting a call out to STW to see if anyone has one in their parts draw they no longer need because their bike isn't a mix of old and new like mine will be.
Happy to pay or donate for it...
I've got a hope 220mm rotor, it is a ludicrous thing of beauty. My only worry is how big a hill I need to find to generate enough heat to bed it in, and how many reps that will take!
It's not actually that much heavier either, I worked out (based on reviews where braking power was tested) that is was about the same power per gram than upgrading from Guides to Codes.
Why would a No.3 caliper space out to 220mm with the HBSM20? No.8 would but definitely not 3.
Anyway, I tried the same thing with my old E4 but somehow the adaptor took it to 195mm (+10mm) I could never get it to work and had already ground bits to fit the fork.
@squirrelking the fork is 180mm postmount not 160mm postmount iirc. The hope convertor is +20 on the calipers disc size when used on 160mm PM. This would give 200mm with a 180mm IS caliper. So on 180mm postmount that becomes 220mm.
Ah yes, okay gotcha. Comprehension failure.
I'd offer mine but honestly can't get it to work, dunno if it was a bad batch or what but I gave up in the end and just got new brakes. Can have another look if you like and if I can get it to work with my M4 then I'll give you a shout.
Anyway, I tried the same thing with my old E4 but somehow the adaptor took it to 195mm (+10mm) I could never get it to work and had already ground bits to fit the fork.
There is a +10 adapter out there, for a while 170mm rotors were an option with Shimano brakes for XC riders with post mount forks and IS calipers.
Possible suggestion, is the rear caliper IS mount and smaller? If the frame's IS then a 180 caliper would be a 160 rotor as frames are generally a smaller mount. Could you swap them round?
@nixie, that's exactly my situation. The Helm post mount is 180mm minimum which makes the Hope adapter (HBSM20H) I bought with +20mm offset push the 180mm caliper too far out.
@thisisnotasppon, thanks, I didn't know Hope 220mm discs existed. I've only had forks where the max rotor size was 200mm, any bigger and warranty voided. I need to check if Cane Creek Helm forks have a max rotor size.
@squirrelking thanks for the offer, if you wouldn't mind checking that'd be great
I'm going to try and avoid new brakes as I didn't forsee this problem and had the M4s stripped down and rebuilt with new seals, pistons and hoses. TBF I'd never had these brakes serviced since getting them on a Patriot in 2004. Only pad changes. That's good going in my book.
@spuirrelking yes the rear caliper must be 160mm, as rear is set up using a 180mm rotor with the HBSM20 adapter attached to the caliper. I think I see what you're suggesting with the switch, so new set up would be...
Front
180mm PM fork
160mm IS caliper
HBSM20H +20mm adapter
200mm rotor
Rear
IS frame
180mm IS caliper
No adapter required
180mm rotor
There is a +10 adapter out there
Mine was bagged as a +0 but fully appreciate lines can get stuff mixed up from time to time. Just a pain I only found out once I'd ground it to fit my fork.