Freehub problems?

[ElyDave]

Is this likely to be a problem?

[vorsprung]

From the photo I am guessing that the "problem" is that a bit of freehub is missing.  Please describe exactly what is wrong, what type of hub or wheel it is and if there are any other problems with the bike (ie ghost shifting)

[Feanor]

Vorsprung: the outer surface ( where the lockring screws in ) has sheared off for about 75% of the circumference, to a depth of about 2mm.
Clearer in second photo.

Depends how much depth of the lockring thread can still engage.
Lockring threaded sections are not very long.

Also, whatever weakening of the material has caused 75% of the circumference to break off has almost certainly affected the remaining 25%.

I'd replace it personally.

[Polar Bear]

I am not an engineer but, if a lockring still screws in and sits firm when the cassette is in place, I'd roll with it.

Is that shimano?   IIRC, sram lockrings are slightly deeper than shimano ones but I could be mistaken.

[ElyDave]

Yes, Shimano.

I guess one option would be remove the rest of the damaged area with a suitable dremmel or similar, grind it smooth and see how it goes.

[LittleWheelsandBig]

Shimano free hubs aren't that difficult to replace.

[vorsprung]

If it is shimano then a replacement freehub should be easy to get and they aren't difficult to install

Dremmelling off stuff will mess up the spacing to the first cog i'd guess

I bought two spare freehubs from this ebay seller last year

http://www.ebay.co.uk/itm/SHIMANO-CASSETTE-FREEHUB-BODY-CONE-AXLE-SEAL-SKEWER-for-8-9-10-SPEED-REAR-HUBS-/301793137847

[DDCyclist]

Where does the cassette get its position? If it's the damaged end of the freehub I'd agree with vorsprung. After removing the last of the damaged piece of freehub you'd need to find some sort of shim to pack out the cassette to its proper position.

Also, I'd be concerned that the damage might go further than 'just' the missing outer edge. I'd be suspicious of the possibility of micro-cracks (or even visible cracks) extending past the locking ring. For that reason I'd almost certainly be treating it with caution, trying not to load it too much and I'd be lining up a replacement.

[Polar Bear]

I believe that the outer sprocket sits proud of the freehub.     

[Feanor]

The cassette position is set by the inner end landing off at the back, with any spacers shimming it as required.
The damaged end plays no part in the spacing.

[Feanor]

I believe that the outer sprocket sits proud of the freehub.     

Yes, exactly the same way that the top of the stem must come above the top of the steerer, so that the cap-bolt actually presses down on the stem, not just compressing the steerer.

So the lock-ring needs to bear down on the cassette, and not land off on the freehub first.

[DDCyclist]

What would have caused the damage? Knowing that may hint at the potential pitfalls of re-use.

E.g. Is there any risk of the bike becoming an involuntary fixie if the freehub breaks up further under stress?

[rr]

What would have caused the damage? Knowing that may hint at the potential pitfalls of re-use.

E.g. Is there any risk of the bike becoming an involuntary fixie if the freehub breaks up further under stress?

Cassette not seating properly leading too few threads engaging, mismatch between hub and cassette, lockring too tight or loose.

[DDCyclist]

What would have caused the damage? Knowing that may hint at the potential pitfalls of re-use.

E.g. Is there any risk of the bike becoming an involuntary fixie if the freehub breaks up further under stress?

Cassette not seating properly leading too few threads engaging, mismatch between hub and cassette, lockring too tight or loose.

Any possibility of a suddenly locked up freehub causing unexpected uncontrolled flying pedals and resultant scraped legs (or even broken ankles)?

[P Walsh]

If it is shimano then a replacement freehub should be easy to get and they aren't difficult to install

Dremmelling off stuff will mess up the spacing to the first cog i'd guess

I bought two spare freehubs from this ebay seller last year

http://www.ebay.co.uk/itm/SHIMANO-CASSETTE-FREEHUB-BODY-CONE-AXLE-SEAL-SKEWER-for-8-9-10-SPEED-REAR-HUBS-/301793137847

Having looked on the SJS site I found numerous Shimano freehub bodies, none of which were deemed compatible with a first generation 10 speed Ultegra hub that I have. I don't think it is as simple as buying any Shimano freehub.

[ElyDave]

I do actually have another hub that needs overhaul, same gen 8/9/10 speed, so should be compatible as a short term caniballisation until I get around to that.

My issue is that I bought this one 2nd hand recently and didn't spot the damage in the railway station car park.  The rest of the wheel/hub is OK.

[ElyDave]

Well that really didn't go as planned

Freehub on spare wheel set was running a bit rough, now I know why. Very wet inside and pitted bearings and race.  New one on order with two dismantled wheels sat in the gym.