Topic: Loose drive chain

[Red750K1]

My '71 Cb750K1 has an o-ring chain on it. I'm not sure how long this chain has been on, it came with the bike.  I've been noticing the past couple weeks it keeps getting loose, i've adjusted the rear axel to tighten up the chain a little bit but it was loose again today. Hmm, worn out?

[eldar]

It is getting worn and it sounds like the sprockets are too. If you have worn sprockets, it will cause a chain to wear out sooner. Replace all 3 as a set.

[Triffecpa]

try pulling the chain off the rear sprocket at the 3 o'clock position.  If you get any substantial movement in the chain (ie half a sprocket tooth exposed) then the chain is worn and should be replaced.  The sprockets need replacing only if the teeth have an uneven (wave looking) wear to them.  Buy pulling at the three o'clock position at the rear sprocket, you are isolating the links.  Effectively you are measuring the wear in the pins between the links.  This is why chains "stretch" as they wear.  They don't really stretch, but the pins between the links wear and they allow movement between the links.

TR