New brakes set up, front pads missing part of rotor sweep

abarth_1200

Couldn't find anything through search about this.

New rotors, shimano adapters and xt brakes. Quick spin and I can see from the wear on the rotors that the front pads are overlapping the rotor as it sweeps round. Rear pads are dead in the middle.

Rear


Front


Only thing I can think of is facing the front post mounts on the forks, but they appear to have been done already.

poah

look at the pads, shimano OE have a slant at the end so don't hit the whole rotor. 3rd party pads don't have this

abarth_1200

Yeah but even still the fronts upper edge (outermost edge) is missing the rotor completely, like the adapter is too big.

I'm wanting to get the best performance out these brakes but if the pad is missing the rotor it's obviously not getting full contact and I can see wear problem further down the line.

You can see from the pics the rear has a couple mm either side of the pad contact area but you cant see the edge of the front pad contact area.

Thanks

poah

sounds like the rear adaptor is either made wrong or on the wrong way?????????

abarth_1200

The rear pad contact area is correctly covering he whole of the rotor with a margin either side.

It's the front with the issue.

Do you guys want a pic of the front and rear calipers too?

cooldad

So maybe the front adaoter is upside down.

abarth_1200

Looks right to me but just for the people in doubt

poah

front looks like mine, rear looks wrong.

abarth_1200

How, it's got an arrow on the adapter pointing up, and it's the same way according to the instructions.

Find me another pic of an xt caliper with is mount frame and 180mm rotor.

Hang on search in google

shimano xt caliper on frame

And see first image of pads worn halfway through which I think will happen to my FRONTS.

The adapter is the right way round, scroll through the rest of the pics and see similar is mounts.

ricardo_smooth

Both adapters are fine. If it was me, I'd try re aligning the calipers. Maybe it's moved down when tightened, so it could be centred, but sitting too low. What are the gaps like fore and aft of the caliper to the disc?

nicklouse

Not a problem. For some reason many set ups are like this don't worry about it.

abarth_1200

Thanks for seeing that the adapters aren't the problem.

There's not much room for it to move down, there's only really movement left and right.

I know what you saying nicklouse but would I be able to file down a bit off each post on the forks or is this a bike shop job and the proper cutting tool. I just don't want the pads to end up wih a chunk of material gouged out them rubbing along the edges of these aluminium and steel rotor sandwiches

heez29

Is the pad in full contact with the disc though?

Try the adaptor the other way around?

abarth_1200

From the wear marks on the machined rotor surface I would so yes it is in full contact, on the parts that run through the line of the pad area.

Other way round, as in turn it upside down or use it back to front, I don't think it will work back to front as the bend in the adapter is there to make room for the caliper. I could however fit it upside down and see if that helps, but it's not the right way of doing things. I'll it tomorrow anyway to see

nicklouse

abarth_1200 wrote:

Thanks for seeing that the adapters aren't the problem.

There's not much room for it to move down, there's only really movement left and right.

I know what you saying nicklouse but would I be able to file down a bit off each post on the forks or is this a bike shop job and the proper cutting tool. I just don't want the pads to end up wih a chunk of material gouged out them rubbing along the edges of these aluminium and steel rotor sandwiches

They won't.

You are worrying over nothing.

Many set ups have been like this for years and work just fine.

If you really want to remove some material you could try and find a bike shop with a milling machine, very rare, or find a engineers work shop and tell them how much to take off the adaptor, don't take the bike.

abarth_1200

Alright I'm convinced I'll leave it alone, after all it's not the end of the world if my pads don't wear evenly, as long as my brakes work to their full potential.

But yeah good point don't take the bike lol, milling shop would only need the adapter.

Thanks br!