Clunky chainset in higher gears: ?

Johnsqual

Senior Retro Guru
Hello,

My chainset is clunking in higher gears. I have a 53-42 on the front and
28-14 on the back. It's fine in 42-28 - 42-19, but makes a regular clunking noise in higher ratios than than, which gets worse the higher the ratio.
The noise gets faster the faster I pedal.

I put a brand new SRAM chain and freewheel on. The chain is the correct one for the F/W. It has a quick link.
The PO had got the pulleys the wrong way round (lower-upper were in the wrong place), but I corrected that and it's not made any difference.

Anyone got any idea what might cause this, and if there's something I can do?
I can't seem to work out what the problem is at all.

Cheers,

Johnny
 
Thanks, had another look at the chain and it seems to be just one link
too long - is this enough to cause the clunking, do you think?

Cheers,

Johnny
 
Has it just started doing this? or was it an existing problem?
Without seeing it, it could be a slightly bent mech hanger, chainline.
If its a new freewheel, again mech/cable adjustment
Daft question, not insulting your intelligence, the chain is fitted around the rear mech properly, I know I've got it wrong on a few occasions.
Not sure whether this helps in any way :)
 
Hello,

Thanks for the suggestions.

I have noticed that there is a bit of play in the freewheel - it's firmly screwed
on to the hub, but there seems to be play between the freewheel body and the
sprocket assembly. It's not a lot, but it's noticeable. Could that be the problem?

The cable is a bit loose in the highest gear, but not very.

It's an old campag SR mech, but it was in good condition when I bought it,
not worn out, and the tension spring seems ok. It's not possible to do the daft thing of threading the chain round the outside of the chain guide (Which I have done with modern shimano derailleurs :oops: )

So is the play in the freewheel likely to be the problem? And if so, is there anything I can do short of replacing it altogether?

Cheers,

Johnny
 
Are you sure it's not the bottom bracket? Wiggle the cranks and check for play. Check the cranks aren't loose to while you are at it, and that all the chainring bolts are tight.
 
Thanks, but I am pretty sure it has something to do with the chain and/or freewheel. I checked for play, loose bolts etc and rode the bike with the old
chain and freewheel for at least 100k with no problems. Problem has only started since I put a new freewheel and chain on there.

It's also more noticeable when riding the bike - when I look for the noise when
not riding it's hard to spot.

:x Frustrating, but thanks for the suggestions.

Johnny
 
Sorry, just to be clear: is it a screw-on freewheel you have or a freehub and cassette?
Is the clonk in sync with your pedalling? Not just speed but leg position?
 
It is a 7 speed sram freewheel, screw on, with an sram powerlink chain,
both brand new.
The noise is a sort of regular knocking sound that occurs in the middle
sprockets, and in when I am in either chainring. It doesn't happen in the smallest sprocket or the biggest two.
It increases as I pedal faster, but doesn't seem to be related to my leg position.

Sorry if that's not much help, I've been trying to identify this for a few days and it is driving me mental.

Johnny
 
Have you checked for stiff links? One chain rivet pin sticking out slightly? Damaged chain roller...?

I know how it feels, this kind of thing is infuriating. My Ti road bike had a click which turned out to be a small bit of corrosion on the axle stub in the dropout. :roll:
 

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