Freehub, cassette or something else?

cgraley77

Hi, looking for some help here please.
I was on a ride tonight and around 3 miles from home when suddenly I found myself pedalling but rapidly slowing down and just managing to unclip in time.
On inspection when turning the pedals (in more than 1 gear), the back wheel was not turning at all.
After eventually making it home (cheers Dad) and checking over the bike, the problem appeared to have disappeared and pedalling turned the rear wheel as required.

What I'm wondering is what caused this problem, and should I take any action? Was it the cassette (Shimano AFAIK), the freehub, or something else? And is there anything I can do to remedy/fix this, or is it one for the LBS?

Many thanks for your help in advance,
Cameron

Wirral_paul

Sounds like you need to give the freehub a service - my money would be the pawls inside this stuck down and so didnt engage.

bikeit65

Sounds like the pawls in the freehub body might be on there way out, this happened on my last bike,now and again the back wheel would not turn when the pedals were turning replaced the freehub body, sorted
http://www.parktool.com/blog/repair-hel ... ub-service

cgraley77

Thanks for the advice. Would you guys recommend servicing/cleaning it, or fitting a new one? I'm not the most skilled person, and I think less could go wrong with a straight replace, for a fairly cheap part (~£20 if I'm correct?).

What do you think?
Thanks,
C

slowbike

Try and service/clean it - you'll learn how it works then ... if you fail then you may have to buy a new part ...

If you don't try you'll not learn!

cgraley77

Slowbike wrote:

Try and service/clean it - you'll learn how it works then ... if you fail then you may have to buy a new part ...

If you don't try you'll not learn!

Very true! Just one more quick question for you knowledgable lot - any idea what size cone wrench(es) is/are req'd? I recall reading 13 and 15mm somewhere but may be wrong...?

Thanks again,
C

slowbike

if you have a pedal spanner they are 15mm - so you could see if that fits ...

if you have to dismantle the hub then do so over some news paper and have a pot to put the ball bearings in.
Don't do it on the sitting room carpet ...

Also - take pictures of each stage before dismantling the next bit - so you can see how it all goes back together.
Finally - before undoing the axle nuts - feel what the hub is like rotating around the axle - as you'll need to do it back up to a similar tension...

racingcondor

Rear hubs aren't all that complicated so my vote is for 'take it apart and put it back together again'.

I'd recommend the following though -
- lay out the parts in a line in the order you take them off,
- clean everything as you put it back together,
- when in doubt, grease everything.

Clearly the last one isn't the 'right' way of doing things but for a beginning mechanic you'll do a lot more harm not greasing the wrong bit than you will by greasing all of it.

You'll need to be a little careful with grease in the freehub as a lot of them have pretty weak springs so use a lot of heavy grease and you'll gunk it up so that it doesn't work. Clean everything though, wipe clean and grease the pivot point on the pawls and you shouldn't have a problem even with a heavy grease.

keef66

Shimano freehub? Don't try to fill it with grease, it's too thick and will stop the thing working especially in the winter. If you can get it off the hub (big allen key to undo the central tubular bolt) and very carefully pick out the rubber seal at the back (remember which way round) you can drizzle some medium weight oil in there to improve things.

Trickiest bit is adjusting the cup / cone bearings when you reassemble them. Too loose is a lot safer than too tight. You need a tiny amount of play with the wheel out of the frame, which should disappear when the QR is tightened.