Formula The One Owners- Help pls!!

Hi All,
I’ve got a set of The Ones, the fronts great but I’ve had grief with the rear…after several bleeds I took it to my LBS and he bled the system through…I took the bike out and after a few miles the brake started to die until I could hold the lever in and the brake didn’t work at all.
So…back to the LBS for a lever rebuild…..i took it out today for the first time after the rebuild and 95% of the time it was great but there was a few times when the brake didn’t do anything, after a few pumps it was ok and back to working well?!

Any thoughts before I just get XT’s

Cheers!!

Have you checked for a leak? Do the pistons move freely when the lever is applied?

You’d have to take a good look around the brake whilst applying the lever to find out more. Unless there is something internally wrong with your lever..

Which version of The One is it? There’s been 2 plus assorted variants and they’re pretty different.

Northwind, I think they’re the 2010 model…not sure though?!

Paul

Lever looks like this?

Not like that, like the more current ones but without the lever adjust bits and bobs.

OK, cool. First thing I’d suggest is that you remove the brake from the bike, and just try squeezing the lever- what you’re watching for here is fluid coming out the back of the lever body (ie, where the handlebar would usually be).

These brakes are pretty straightforward to bleed, but the reservoir is fairly small so if air is left in (when bleeding) or gets in (via a leak in the diaphragm at the back) then it’s likely to get into the working fluid and cause your symptoms. They revised the diaphragm slightly in later models to make it more durable which always suggests to me that the original design wasn’t quite right.

Equally it could be that the main pressure piston is damaged or worn but that’d usually be more consistent.

Ok cheers Northwind, I’ll take it off and have a looky

Cheers, Paul