Post mount fork – brake caliper thread stripped

I've manage to strip the thread from one of the brake caliper mounts on my Fox Talas forks. It's the upper one stripped doing the bolt up too tight. 😳

I've put a lightly longer M6 bolt in there and its holding tight, should I trust it?

The bolt is approx 6mm longer than the old one. I plan to get it fixed properly (if possible?) at my LBS probably next week, but need the bike for a long enduro on Saturday so no time to fix before then.

What d'you reckon?

Tap it and put a heli coil in. Best thing to do and will cost you £25 from halfords

Its unlikely to fail catastrophically ( 2 bolts, angle of bolt etc) but if it does the consequences could be very unpleasant indeed.

No way would I ride it

Tap it and put a heli coil in. Best thing to do and will cost you £25 from halfords

Is this easy to do? I don't want to wreck it completely.

Tap it and put a heli coil in. Best thing to do and will cost you £25 from halfords

Is this easy to do? I don't want to wreck it completely.

When you brake the caliper wants to rotate forwards, so it would be pulling against the lower bolt and pushing against the top mount. So in reality the top bolt doesn't do anything other than keep the caliper in the right position, so I don't think you have a problem.

If it was the lower bolt and you had a wavey rotor, then it's possible that braking with the rotor in a certain position would cause a lock up if the caliper pulled away from t's mount slightly.

I would have no problem riding it as it is.

How much did the shorter bolt protrude? Can you see/measure how much good thread is left (Try and feel the thread with a needle)? If there is more than a few mm left I'd say its fine.

Also thinking of trying an even longer bolt in there for more security?

Not too hard to do i did a friends last week. I have some Talas 36 myself and if they are the same they have enough material to tap it but just go slow and make sure its straight.

DONT GO TOO DEEP otherwise you will go into the leg its self and then you are screwed.

Helicoil is asy to do. If you can use a tap you can do a helicoil. The kit is not cheap altho the helicoils are. Its the sort of thing any decent engineering shop or LBS could do for £10 – 20

How much did the shorter bolt protrude? Can you see/measure how much good thread is left (Try and feel the thread with a needle)? If there is more than a few mm left I'd say its fine.

Not checked this, but the new bolt is 5mm or so longer so there is at least that much thread.

If you have the correct tools, tapping for a helicoil is easy. It is possible to wreck it, but only if you're particularly special. You can probably buy the tools for a fraction of what your bike shop will charge. Might be worth seeing if you can use/borrow from a local engineering workshop.

Halfords do a kit with the bolts and all you get about 6 heli coils in the pack. Think i used m6

as long as there's a reasonable amount of thread in beyond the stripped bit you shoudl be fine.

you coudl araldite the new one in for additional scurity (or threadlock for something that's going to be easier to remove afterwards).

Paulrockliffe +1

In normal use, you shouldn't be putting significant/any(?) tension into the bolt. If you somehow generated a lateral force to overcome the friction between the caliper and the face of the post mount, you would still need to shear the bolt off… which is a big force and therefore unlikely.

Oh, and maybe invest in a torque wrench!

A mate did the same to his Fox's – he took it to a local engineering place and they helicoiled it. It's probably stronger now than it was originally

Helicoil could be the best option
there is a video on here
http://www.emhart.com/products/helicoil.asp

makes you wonder why they do not fit helicoils as standard.
Just one thing that I would ask is about the original screw / bolt it is just a guess but was it too short to start with and therefore the reason for the problem ?

It was just a standard Hope Mono Mini bolt – M6 x 20mm I think.