Problem with rear hub?

davidwilcock

Hi

I have a problem, my chain (when on the small chain ring) bounces and knocks on the chain stay when i freewheel and hit any sort of mildy rough terrain. I thought this might be because my chain is too long but it looks reasonable when compared to others. Is this the issue?

Probably related - my pedals go round like its a fixed gear when i push the bike along. I can stop it by holding the pedal without a lot of force but it seems weird. I have greased the pawls and everything else down there but this has not solved it

Many thanks all

keezx

Mavic wheel?

davidwilcock

Its a Planet X CT45. Its quite new

Origami02

It sounds like your free hub pawls are jamming. You'd need to remove the free hub body to see what is actually wrong.

davidwilcock

I took off the freehub and removed the pawls, regreased and put them back in. Didnt solve the problem though sadly and I couldnt see an issue. Is there something else I could do or look for?

frisbee

Chain stretch? Simple test is to try and pull it off a chainring.

Could also be jockey wheels or rear derailleur pivot.

dee4life2005

I'd put money on your rear derailleur needing cleaned, particularly the pivot spring area that the jockey wheel cage rotates around. I suspect this isn't taking up the slack on the lower half of the chain, causing chain slap when you freewheel - have you got a nice oily stripe going over your chainstay ... I did when I had this exact issue.

To check if it's this. Move the jockey cage by hand and it should spring back fairly easily. If it's at all sticky, give it a good clean. Same goes for the top pivot spring where it attaches to the derailleur hanger, but in my experience it only ever seems to be the bottom one that has the problem.

I found this particularly useful ... http://www.parktool.com/blog/repair-hel ... r-overhaul
(note: if you're taking the springs out to clean it thoroughly, make sure you wind them back in the correct direction or you'll knacker the spring)

ugo.santalucia

dee4life2005 wrote:

I'd put money on your rear derailleur needing cleaned, particularly the pivot spring area that the jockey wheel cage rotates around. I suspect this isn't taking up the slack on the lower half of the chain, causing chain slap when you freewheel - have you got a nice oily stripe going over your chainstay ... I did when I had this exact issue.

To check if it's this. Move the jockey cage by hand and it should spring back fairly easily. If it's at all sticky, give it a good clean. Same goes for the top pivot spring where it attaches to the derailleur hanger, but in my experience it only ever seems to be the bottom one that has the problem.

I found this particularly useful ... http://www.parktool.com/blog/repair-hel ... r-overhaul
(note: if you're taking the springs out to clean it thoroughly, make sure you wind them back in the correct direction or you'll knacker the spring)

I tend to agree...

davidwilcock

dee4life2005 wrote:

I'd put money on your rear derailleur needing cleaned, particularly the pivot spring area that the jockey wheel cage rotates around. I suspect this isn't taking up the slack on the lower half of the chain, causing chain slap when you freewheel - have you got a nice oily stripe going over your chainstay ... I did when I had this exact issue.

To check if it's this. Move the jockey cage by hand and it should spring back fairly easily. If it's at all sticky, give it a good clean. Same goes for the top pivot spring where it attaches to the derailleur hanger, but in my experience it only ever seems to be the bottom one that has the problem.

I found this particularly useful ... http://www.parktool.com/blog/repair-hel ... r-overhaul
(note: if you're taking the springs out to clean it thoroughly, make sure you wind them back in the correct direction or you'll knacker the spring)

That describes the problem perfectly, I'll give this a try tonight and report back, thanks for this

davidwilcock

Unfortunately the derailleur was ok, ive take another wheel off another bike and it seems like the freewheel spins a bit easier (non scientific test). Can it be possible that the pawls are just that bit too stiff?

ugo.santalucia

davidwilcock wrote:

Unfortunately the derailleur was ok, ive take another wheel off another bike and it seems like the freewheel spins a bit easier (non scientific test). Can it be possible that the pawls are just that bit too stiff?

Maybe they are a bit sticky... 2 x 5 mm allen keys, a rag and some grease is all you need

Origami02

From what you're saying there appears to definitely be drag on the free hub body, be it internally from the free hub bearings or ratchet mechanism, or externally via an axial load .
Have you checked the torque on what-ever retains the free hub body itself ? It may be retained by an end cap or by a shoulder on the axle itself.
Have you checked that the free hub bearings turn freely ?
Does it drag irrespective of which cassette is fitted ?
Are the pawl springs seated properly so as not to be under too much tension?
Some free hubs only need light oil rather than grease on the pawls. eg Mavic
Is it possible the axle is slightly bent or burred?

davidwilcock

Thanks All

I had recently installed a 11 speed hub. It appears that the pawl springs had been installed the wrong way round when i bought it(not by me). Imagine the spring makes a Nike tick shape, the tick was upside down so there was just that little bit too much resistance.

Thanks for your help on this. This workshop forum has been a really helpful place for a while, it is much appreciated

ugo.santalucia

davidwilcock wrote:

It appears that the pawl springs had been installed the wrong way round

That's a first... :shock: