Freewheel slipping

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niloc
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Joined: 22 Dec 2008, 9:54pm

Freewheel slipping

Postby niloc » 25 Apr 2011, 7:50pm

One of our bikes has a freewheel which appears to be slipping and making an occasional "klonk" sound (different from the typical "chain slip" sound). I recently had to oil it because it was stiff but its now making the nice "krrrrrr" sounds again as it should. But is it possible that pawls are now sticking and allowing it to slip?

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gaz
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Location: Kent, car park of England

Re: Freewheel slipping

Postby gaz » 25 Apr 2011, 9:59pm

Possibly, but freewheels are not the easiest thing to take apart and reassemble.

I've had a freewheel fail and freewheel in both directions. I was lucky. It was on a clubrun and I was pushed two flattish miles to the cafe and only had a mile walk to the station and a similar walk back home after the train ride.

Had I been somewhere more remote it would have been much more unpleasant.

If in doubt I'd fit a new one.
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PW
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Joined: 23 Jan 2007, 10:50am
Location: N. Derbys.

Re: Freewheel slipping

Postby PW » 25 Apr 2011, 10:37pm

Take it off and flush it out with WD40 until the brown gunge stops coming out. Then re-lube it with thick oil &/or Molyslip. You'll need to remove the rubber O ring from the hub end of the unit to get the oil in.
If at first you don't succeed - cheat!!

robinlh
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Joined: 20 Feb 2010, 10:26pm

Re: Freewheel slipping

Postby robinlh » 27 Apr 2011, 5:36pm

the outer retaining ring on a freewheel is threaded anti-clockwise,i.e.backwards.
take it off,,put the thing on a remover clamped in a vise and loosen the outer ring,using a punch.
then,over a big tin or something,take it off.
all sort of stuff will shower into the tin,mainly ball bearings.
Depending on the freewheel you will see that one or more of the springs that retain the pawls have broken.
But they may be just gummed up,or have slipped out of engagement.
you probably wont be able to get spares,this is 2011,but you may just find that you can cobble something up.
When replacing all those balls you have to use some grease and be patient.
Or buy another one,they are cheap,but very limited in terms of sprocket size,14-28 being available.
If you have an old french freewheel that goes from 13 to perhaps 32 and you want another one you can always email me ,there is probably something in a box somewhere here,but i'm off on tour from Sunday for 14 weeks so this may not be the most useful solution!
Robin

spanner
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Re: Freewheel slipping

Postby spanner » 27 Apr 2011, 8:14pm

i usually flush out freewheels with wd40 then leave the freewheel submerged in engine oil (even used oil will do) overnight then hang it up to allow the excess oil to drain out of the freewheel
give it a wipe with a cloth to take any oil off the sprockets and refit then roadtest the bike when you will find that the freewheel does not tick absolute bliss
the only thing that happened to me was with my 57 flying scot on a VCC run last year when the ring that holds all the pawls etc in came undone for some reason but managed to get it back in but it did the same again but with the use of a screwdriver and a dumbell spanner as a hammer managed to get it tight again.
i did manage to complete the run and took the freewheel off and tightened it with a centre punch and hammer then peened it and its never given any bother since.
i did try to fit a 32 t megarange freewheel as the campag rally rear mech (according to velobase.com) says it takes a max 36t sprocket so cant understand why the mech wouldnt take the chain up to the top sprocket even though it is 6 speed
any suggestions as to why i cant use a 32 top sprocket 6 speed freewheel with a campag rally mech?

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gaz
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Re: Freewheel slipping

Postby gaz » 27 Apr 2011, 9:49pm

spanner wrote:any suggestions as to why i cant use a 32 top sprocket 6 speed freewheel with a campag rally mech?


IIRC (and sometimes I don't) the length of the gear hanger can also come into play in determining maximum tooth capacity. I once had a Shimano Deore XT Super Plate what had a quoted capacity up to 34T on it's standard hanger (28mm?) but a whopping 38T on a longer hanger (40mm?).

If my suspicions and recollections are correct I'd guess your hanger is 24mm, giving a max around 28T.
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spanner
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Re: Freewheel slipping

Postby spanner » 28 Apr 2011, 11:17am

gaz wrote:
spanner wrote:any suggestions as to why i cant use a 32 top sprocket 6 speed freewheel with a campag rally mech?


IIRC (and sometimes I don't) the length of the gear hanger can also come into play in determining maximum tooth capacity. I once had a Shimano Deore XT Super Plate what had a quoted capacity up to 34T on it's standard hanger (28mm?) but a whopping 38T on a longer hanger (40mm?).

If my suspicions and recollections are correct I'd guess your hanger is 24mm, giving a max around 28T.

strange that velobase quotes the max teeth size as 36 not 28 also would the chain length be a factor in this
am also pondering that if the wheel isnt dished for a six speed block to strip a 5 speed block and the mega range block and fit the 32t sprocket and the other 4 sprockets which came off the five speed block worth a try i suppose.
i will also email someone in my section who built up the scot for the member(now ex member) who i bought the bike off as he will be able to advise me as to the max capacity the mech can cover

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gaz
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Re: Freewheel slipping

Postby gaz » 28 Apr 2011, 4:16pm

Spanner, I have no knowledge of the max capacity of the Campag mech in question. My remarks are purely speculative, based on the varied max capacity (dependent on hanger length) quoted for a late 80's Shimano mech.

Sorry that my previous post wasn't clear. :oops:
Hand wash only. Do not iron.