I haven’t used the bike on which they sit for almost a year, and the brake lever has become very stiff – it travels only a few mm before the brakes bite. There’s no modulation left, obviously. How do I fix this? Will a bleed sort me out? I would expect the opposite problem (lever too soft), and I know how to fix that, but this baffles me somewhat. Is it because the brake fluid has absorbed water or something which increased its volume? Advice will be much appreciated – thanks!

Piston seized? Buy Shimano.

A bad case of aviditis, get some shimanos 😉

Its only 3 bolts to get them off the bike.. Undo them all.

Probably a sticky piston. First would be to remove the wheel and try to push the caliper back in with a plastic tyre lever. If it moves then you may be ok or a bleed may help. If it doesn’t then you will need to sort out the pistons which is a faff.

Yes it has absorbed water, even though its a sealed system. Quick fix is to let out a little fluid, but generally will need a full bleed. Longer term get rid of them, poor brakes. IMO

I’ve the same. Been googling and found a fair few bits about the heat causing it. Tis hot today ??

Had the same heat related issue on my son’s Spesh Carve with elixir 3’s.

So we could get out riding yesterday I had to bled off a little fluid as they front brake was locked on.

They still were not good. They fouled the disc despite repeated attempts to re-align the caliper etc.

When we stopped for a rest (even leaving the bike in the shade) they made a horrendous noise when we set off again and we ended up cutting the ride short.

A set of deore will be ordered on Monday.

Just a quick question. His set up is 180/160 (f and r) – can you use the same rotors or will there be an issue? I seem to recall that the 180 rotors from avid don’t line up with shimano calipers or something? Is that right?

Hope you get yours sorted OP.

Just ran cold water over mine for ages and its sorted it. It had been left in the back of my car all morning so was very warm.

Normal man, just unbolt the brakes and fit using the old brackets. It should be fine.

Ashmonkey, that seems a sensible cure, its not like they ever get heat soak from long distance braking, is it ?

Did the Gorrick today with my Elixirs and I am not a lightweight. Have Uberbike floating rotors and organic pads today on mine and they worked fine, although I don’t like them in the same way the shimanos work on my other bikes. Might get a cheap set of XT’s from Merlins as have a 10% off voucher too ……

Thanks for that. I’m binning them and will get some Shimanos. Not Deore though – the last OEM set I had also had a stuck piston. New SLX or XT if they’re on a good deal seems the way forward. Will the Avid rotors work ok? I thought there was a small issue over size difference or something?

Shimano don’t recommend it but it will be fine, just make sure they’re not 185 rotors with 180 adapters