Chain Slipping one gear

[ISC23]

Hi,

i've just fitted some new wheels, a new 7sp cassette and chain to my daimant commuting racer (1980s). For some reason the chain slips in one gear when i stand up going uphill. Does anyone have any experience of this?

Like I say, everything's new so it rules out the kit pretty much, I wondered if it might be to do with chain length, maybe I've cut it too long?

I thought I'd ask here anonymously before trundling off to the bike shop to be patronised.

Any help greatly appreciated,

cheers

Iain

 

[Old Ned]

I've had experience of what happens when the chain slips standing up going uphill :evil:

Do you have a stiff link anywhere in the chain? Which sprocket slips, always the same one? Any machining defects on it?

 

[ISC23]

many thanks for your reply.

what do you mean by stiff link? perhaps the link i refitted is stiff somehow...

it tends to be the central gear in the block 4th or 5th gears.

i don't think there are any defects on the cassette, but will check tonight (its my girlfriends commuter).

Iain

 

[ISC23]

many thanks for your reply.

what do you mean by stiff link? perhaps the link i refitted is stiff somehow...

it tends to be the central gear in the block 4th or 5th gears.

i don't think there are any defects on the cassette, but will check tonight (its my girlfriends commuter).

Iain

 

[Old Ned]

A stiff link is one that doesn't 'pivot' freely - it's stiff! Check along the length of the chain and when/if you find one, 'bend' the chain from side to side at this point which should free it. Alternatively, try pushing the rivet back in from the other side VERY slightly. Some riveting tools have two chain positions, one which supports the chain from the rear to be able to push the rivet in and another in the 'middle' of the tool which is used to ease the rivet slightly and remove any stiffness.

 

[ISC23]

that is sound advice, i'll have a try tonight.

great stuff cheers

Iain

 

[ISC23]

gave chain a pretty thorough once over, looked for stiff links running through and getting caught in the cage, nothing there.

and chain slipping again this morning.

any other ideas? its driving me a bit nuts!

 

[Jonny69]

Are you doubly sure it's the chain slipping and not the freewheel mechanism jumping?

 

[ISC23]

thanks for your reply,

can't be doubly sure its not the freewheel, not sure how i can check as it happens at random, being in the same gear is the only constant.

 

[Jonny69]

What you can do is put the bike in the gear it jumps in, stand on the chain side and watch it while you stamp on the pedal to see if you can get it to break loose. Turn the crank round a bit, click it back a few on the ratchet and rinse and repeat. There might be a few sticking pawls in the mechanism.

Or alternatively, put the bike in the gear it jumps in and ride it around just fast enough that you can balance and stamp the pedals back and forth on the ratchet.

Obviously don't really lamb it with all your leg powah, just enough to break it free.