I bought the KCNC post mount to IS 160 adapter, the one that only fits to some callipers due to the shape. I'm trying to fit some Shimano XTR from 2007 to this 2013 Trek Superfly FS. The calliper fits the adapter, it all fits on the frame but the calliper is about 3mm out. Not 20mm, just 3. WTF? Has IS changed over the years? It's a Shimano 160mm disc.
Clearly this adapter fits something, otherwise it would not have been produced. So what is going on?
Even though it is a 'standard' there is usually a bit of variation between calipers, disks and adapters. Normally a mm or 2 and doesn't really matter. If its enough to make it rub then a washer between the adapter the caliper sorts it. Or do you mean you need another 20mm? In which case just get a 180mm adapter or you are mixing front and rear kit. There is 20mm difference between a front and rear adapter
3mm in which direction?
Is adaptor on the right way round?
The calliper is 3mm too far from the wheel axle. So if I used it it'd be making a lip on the brake pad, if you see what I mean.
It definitely only goes one way round.
File?
That's very weird..
Apparently IS is different front and back. The mounts are slightly further from the axle on the front. Who the **** came up with that idea?
IS is different front and rear, but it's a noticeable difference, not 3mm difference.
yeah they are different molly but the difference is that a caliper that needs a 180 disk up front uses a 160mm disk out back and vice versa.
not 3mm.....
are you absolutly sure its clearing the fork and not sitting up on a lip ? my sids looked like it fitted from the outside but had similar issue to you and found it was lifted on the inside.
given its 3mm i would just file down the bracket to a point that was suitable to make it all work nicely if your that fussed
but do remember you need to leave some clearance.
a caliper that needs a 180 disk up front uses a 160mm disk out back and vice versa.
Yes, I know about that. The original rear calliper is the long leg version for 160mm disc on the rear. The KCNC adapter fits beautifully, and it's aligned, but it's about 2 or 3mm too far out from the axle.
Would you like a pic?
I thought about filing the adapter, but it's maybe 5-6mm thick so I'd be losing half its material.
Ended up buying a new post mount caliper but I can't fit it yet as I couldn't find the appropriate banjo hose fitting. So if there's another solution I would use it and return the caliper.
Apparently IS is different front and back. The mounts are slightly further from the axle on the front. Who the **** came up with that idea?
It made perfect sense TBF, use the same calipers Front and Rear, mount placed the front 10mm further outboard so you could run 180/160 rotors...
Could the mount be for hope brakes? IIRC those used to use 203/183/165 rotors...
Hope rotors are 203/183/160 aren't they?
It's advertised as being 160 PM to 160 IS. The caliper is already a 'rear' one in that it's for a 160mm disc on the rear.
Adapter is listed as being for forks, not frames. In other words, front.
Smallest pm is 160 right? So this adapter is having to move the caliper out of the intended pm location. I assume it's not putting it in the right place.
If it was mounting the IS caliper higher or lower physically, it probably would allow the pads to side at the correct radius of the rotor.
Ovalising the pm mount holes or a different adapter?
Ovalising the pm mount holes or a different adapter?
It needs to go down, not side to side. Not enough material on it to modify, don't think.
Could just be made badly I suppose. It's the same one that's been mentioned on here several times.
New caliper is a right heavy lump.. but it's got those finned pads so it needs to go on the front really. The old caliper that's on the front now with a 160 to 180 pm to is adapter, that fits on the rear too. Cannot put the 160 to 160 adapter on the front though with the +20mm caliper; adapter fouls the frame.
Yes, down. I looked up that adapter and see it's already slotted side to side.
I bet you'd have more luck with a 180 rotor and a Shimano adapter (or magura) rather than this "problem solver" adapter
180 rotor doesn't fit in the frame.
Pretty sure I had the same problem with KCNC adapters front and rear.
Interesting. Perhaps they are just cack.
Keep thinking I should try modifying it, but common sense tells me to return it get my 14 € back.
And be left with the prospect of buying at more than 14 quid a calipers that fits ?
Not got much choice, have I? Really don't think I can file enough off the bracket.
What about 1/2 off the caliper and 1/2 off the adapter?
It's an IS caliper. I looked at ovalising the bolt holes but they are threaded and also there is not much material on it...
Really looks like the adapter is just duff.
trying to fit an IS caliper to a PM frame/fork is always going to be a bit of a bodge.
tbh it would be easier to go out and get some PM brakes. Any reason why you want to use the 2007 ones? Dual control levers? Should be possible to use them with newer shimano PM calipers.
Any reason why you want to use the 2007 ones?
Cost.
I think my conclusion was that it wasn't going to be a problem - easier to file the pads than the mount.
When the pads got really worn the top ridges risked touching and stopping brake being fully effective but so long as i took the lip off would be fine. Only needed to do it once on each pad.
Hmm.
Another solution would be to fit a 203mm disc on the front. I could then get another PM to IS +20mm adapter, that would fit.
Bit silly to have 203mm on an XC bike tho.
Oh wait.. won't work. The caliper adds 20mm and the clamp adds 20mm, which comes to 200mm not 203mm.
If it even works that way. The problem I think is that the caliper I had on the rear is the long legged version and the adapter wasn't designed for that. It's quite a different shape to the short legged version.
Bugger it all.
