OK, on my trusty old Patriot I have Hayes HFX Nines front and rear.

For some reason the front one just won't (can't!) align properly.

I'm running an old Marzocchi Z150 fork so I have an adaptor for the brake. The wheel is a Hope Bulb hub.

Normally to align a Hayes brake I just loosen the bolts and clamp the brake on and re-tighten them – job done.

But if I do this the rotor still rubs! If I look at it carefully the inside piston is fully in (and it's this side that is binding).

It's almost as though the caliper is not far enough over towards the wheel – but it's adjusted as far as it can go.

OK, I could put some shims onto the adaptor to move it over a mm or so, but I'm just wondering why it doesn't want to align properly in the first place.

with some hub-fork combo's the spaceing can be a little out, in which case a couple of shims between the adapter and fork will sort it, or it could be sticky pistons and you need to do the in out in out bit on the pistons

Make sure both pistons are moving when you squeeze lever. Push them back into the caliper, when you pump the lever they should move out at the same rate. (Don't pump too far or they'll pop out)

If one piston is stuck, hold the other in and work the other in and out, if its still lazy pump it out as far as you dare (5mm?) and add a drop or two of brake fluid, before working it in and out again.

I always find it better to push the pistons in, then align the caliper over the disc by eye, rather than relying on the squeezing the brake lever and hoping the pistons will centre the disc.

I seem to remember Hayes making a wider mount for certain forks, Marzocchi definitely used to supply some forks with large spacers(about 5mm thick) for the disc mounts, maybe one of these applies to your forks.

I think Coatesy might be right….

The caliper moves in and out fine when there's no wheel in the bike. Put the wheel in and the inside piston simply rubs, even when fully retracted.

So what happens is the brake is applied and both pistons move at the same rate but the inside piston is pushing the rotor over to meet the outside piston.

I'll stick some shims in – just never had a problem with Hayes in the past. This is a brand new lever and caliper so was just wondering if there'd been any changes in the design.

If you are running an old Z150 fork then you will need a big shim / spacer in-between the fork and the adaptor, approx 5mm? The Z150 and Z1FR that I've had were both like this.

I had that combination on my ASX and the adapter i was using was 16.5mm thick.

Walleater – it is about that far off! I'll dig a big shim out of the tool box.

It's rubbing and I reckon is about 1mm out of line even with it pushed as far over on the adaptor as I can get it.

Cheers people – I just wanted to make sure I wasn't being a mong.