feels like a stiff link, but.....

[shobo]

...that annoying 'click' you can sometimes feel through your transmission, caused by a stiff link skipping on the pulley and which often recedes with time or lubrication.
I've got this happening now - but
- I've run the bike on a stand, felt each link, no sign of stiffness
- chain is still good, not too worn (maybe 50% life left)
- cassette still good (again, a little worn on some sprockets)
- hub bearings seem fine
- freehub bearings seem fine, though its hard to tell with these, and its not symptomatic of them anyway
- bottom bracket bearings fine
- chainrings all good

The 'click' is getting a little worse every few tens of miles, and can happen in any gear, and I'm not even sure its a fixed period.
Its something that happens only under load - there is no sign of any problem with bike on a stand.
Need to get this sorted as this bike is going on a Raid few days time. Would rather not have to replace every bit of the transmission trying to find it. Doesn't make any sense.
Inspiration anyone ?

[Brucey]

could there be a fault in the freewheel mechanism? For example play in the freehub bearings? Sometimes this can cause the freewheel mechanism to skip forwards one (ratchet) tooth at a time.


FWIW stiff links are often most easily found by detensioning the chain (eg by holding the bottom of the RD forwards) whilst pedalling/backpedalling. Stiff links tend to show themselves as they pass through the RD.

Also NB the chain could have a cracked sideplate, and the jaggy edge of the cracked sideplate could be lifting that link off the sprocket. In a similar vein a chain with a joining pin that isn't set quite right can have the joining pin protruding slightly; this can snag on the adjacent sprocket too. In both the above cases the bad part of the chain won't necessarily snag on the adjacent sprockets every time it passes through the cassette; not all sprocket teeth are designed to snag the chain in the same way e.g. when a shift is initiated.

cheers

[shobo]

Interesting brucey, thankyou.
Clever.
no other explanation yet....
better get myself a new wheel and freehub sharp

[Brucey]

also see additional comment about possible chain faults

Trying a different wheel with/without the same cassette/chain should tell you something.

cheers

[NATURAL ANKLING]

Hi,
Had me Foxed for awhile
Brucey has already said wind the chain backwards on stand, Get the chain running straight off the sprockets and the chain wheel, ie. a good chain line, Then turn the The crank smooth and relatively fast backwards.
If it skips you can sometimes show up as a kink in the chain, And a hiccup with the rear derailleur.
Another problem is if you have ramps on the front chain wheels on the chain line is not good it can show up as a minor tick.
Put the chain on the smallest cog at the back And look for catching on the ramps On the chain wheels.

[9494arnold]

And once you have done that .......and still not found the cause...

Have a look at the Spoke Nipples. Myself and another one of our CTC group who know our way around bike problems had real issues with a members tandem that developed a distinct click , generally under pressure . Turned out (after much research) that one of the spoke nipples had partially stripped it's thread ,the noise was the spoke thread 'rasping' against the nipple thread.

[rotavator]

Have you checked that the correct quick link has been used to join the chain?

[hamster]

I had something similar - one link was slightly distorted and pulling open.