Rear hub failure

bikepacker · Post by **bikepacker** » 12 Oct 2007, 5:15pm

As anyone come across this problem.

My rear XT hub started making a screaching noise. I stripped it down to find that the gear that is part of the hub and locates into the freehub had come adrift. It looks like it is sweated onto the hub or press on under pressure.

I think the hub is scrap unless anyone can tell me different.

PW · Post by PW » 12 Oct 2007, 8:27pm

That's a new one on me. I think you're saying that the insert which has the spline teeth & accepts the 10mm allen bolt is loose in the hubshell. If it is then the only bodge I can think of is Araldite, and I doubt if there's enough gap between the parts for that to work. I'd scrap it, keeping the freehub, axle & cones as spares for the next one.

bikepacker · Post by **bikepacker** » 12 Oct 2007, 10:09pm

Yes. I was thinking along the same lines as you. Keep the parts and scrap the hub shell.

Did think of Araldite but I don't this it would take the stresses on the part.

PW · Post by PW » 12 Oct 2007, 10:14pm

We're agreed then, bin it! :cry:

bikepacker · Post by **bikepacker** » 13 Oct 2007, 11:37am

What's the world coming to? Me and PW agreeing in public.

Post by Si » 13 Oct 2007, 2:05pm

I've had the freehub body come loose before, and it did make a foul noise. But I assume we got to it in time as it didn't seem to have damaged itself - all went back together with no problems.

PW · Post by PW » 14 Oct 2007, 5:44pm

I'm scratching my bald patch over a grinding noise at the mo' on the hack. I thought the rear bearings were shot, (no) or the freehub working loose (also no). I've replaced a knackered front mech which was dragging on the chain, checked the rear "B" screw adjustment & there doesn't appear to be anything wrong with the B/B. Pedals are brand new. Still the bloody thing groans in inner ring 1 & 2. :?:

hamster · Post by **hamster** » 15 Oct 2007, 1:02pm

I have experienced the 10mm bolt that holds the freewheel into the hub fail - it cracked through around its head. The axle holds it in place, more or less.

bikepacker · Post by **bikepacker** » 15 Oct 2007, 1:54pm

It wasn't the 10mm bolt that failed it was the part attached to the hub with the female thread. I agree Hampster it would not completely fail as the axle and cones were keeping it in place but the stresses of pedalling were creating movement at the fracture causing the noise.

nobby · Post by **nobby** » 15 Oct 2007, 4:18pm

bikepacker wrote:Yes. I was thinking along the same lines as you. Keep the parts and scrap the hub shell.

Did think of Araldite but I don't this it would take the stresses on the part.

I know nothing of this but it maybe worth contacting Loctite who do a range of metal securing glues. With their help, and a free tube of stuff that they gave me, I was able to repair a frame part on a BSA M33 many years ago.

CJ · Post by CJ » 16 Oct 2007, 2:31pm

Did the failed hub look anything like this:

Also a Shimano XT hub, reported to me by CTC member Fred Lloyd in March this year. I thought it was a one-off. Maybe it wasn't.

bikepacker · Post by **bikepacker** » 16 Oct 2007, 4:07pm

Chris.

Tried to upload a couple of pictures but cannot get it to work. I have sent an email to technical department and attached them to it.

Cheers

If anyone else wants to have a look go to http://www.bikepacker.co.uk/hub.htm

Post by **Mick F** » 16 Oct 2007, 4:25pm

I dragged them from the website onto my desktop. then uploaded them onto here!

bikepacker · Post by **bikepacker** » 16 Oct 2007, 4:30pm

Thanks Mick

dbrunner · Post by **dbrunner** » 16 Oct 2007, 6:31pm

It looks to me as if the main body is threaded as well as the smaller part that has come adrift.

If that is the case then I would have expected the freehub retaining bolt to thread into the smaller part as well as the main body, thus adding continuity to the construction.

If the freehub bolt is not long enough then all the torque is being applied to the inset, not good.

Hard to tell from the photo though.

Odd... Dave