Formula R1 Leak

Discuss light weight issues concerning mountain bikes & parts.

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Posts: 156
Joined: Thu Jun 03, 2010 12:47 pm

by damond

Hey guys!

I was wondering if anyone can help me with this issue. The diaphragm of my R1's broke and the brake lost all the pressure (obviously).

After some searching i found out an website which sells spare parts for Formula Brakes. The problem here is that i have no ideal how i should disassemble the old cap of the diaphragm...does anyone know how to solve this? I cannot unscrew it because it has some small "pins" which make it impossible to rotate as you can see in the picture!

The lever and the old diaphragm:

And the new one that i bought to fix it:

Thanks in advance


by Weenie

Posts: 15
Joined: Fri Sep 25, 2009 7:38 pm

by rycki

To remove that cup I used seger pliers. Unscrew counterclockwise. Be careful, it can be tightened.


Posts: 156
Joined: Thu Jun 03, 2010 12:47 pm

by damond

Hey Rycki!

Thanks for your answer! Is your R1 lever the same model as mine? The problem is that 4 small "dents" which turn it not circular!

Posts: 182
Joined: Fri Sep 06, 2013 1:21 am
Location: Canada

by EvoUltimate

I had the exact same issue last season. I saw R2-bike selling the pin tool and calliper bore tool before but i can't no longer find them on their website. I sent my R1 brakes to Charlie @Formulaand got them fixed free of charge.

Posts: 9
Joined: Wed Oct 19, 2005 11:28 am

by Udi

Probably too late, but for anyone who reads this thread later, there are two types of bladder cover shown in this thread.

The black one (four holes in square pattern) is older and is threaded in with very fine threads. The silver one is a later design, introduced in the MY2011 'R1' and 'The One' and it must be pushed down slightly and rotated 90 degrees at which point it will just slide out - there are no threads.

For the silver "push" type (two holes in a line pattern, with smaller hole in center for air escape), you can install two spokes in a vice firmly (with the shortest possible length exposed to reach the holes in the lever back) and use that to carefully depress/rotate the silver cover and remove it. I initially depressed the silver cap with zero rotation (and a bleed hole opened) about 1mm to make sure it was not stuck, which makes the rotation step easier.

The older design has very fine threads so care needs to be taken to not cross-thread when reassembling. I have also heard reports that the diaphragm is glued on in this model, so both cap and bladder are replaced at once. I do not own one to confirm, but I suspect it is correct.

You need to choose the correct model diaphragm and cap that corresponds with your brake. If you don't damage the cap on the silver "push" model, you can re-use the cap and just purchase the bladder, it is not glued on from what I could see.

Hope this is useful to someone searching in the future.

by Weenie

Posts: 29
Joined: Fri Oct 16, 2009 10:43 am
Location: Cambridgeshire - UK

by cws196

Absolutely correct!

The first R1's (MY 2009) did have a bladder that was bonded to the cap. I find on average (from my experience) the diaphragms on Formula levers need replacing at least every 2years. That is experience with both types of diaphragm on MY2009 R1's and MY2012 T1's.

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