CG125 rear wheel not turning smoothly

[hollisharri]

I've noticed for a little while now that my rear wheel does not turn perfectly smoothly. When I rotate it by hand, it's easy to turn but there's a very small "clunk" about once per revolution. If I stop on the spot and go back and forth then it does not reappear until I roll the wheel around again.

If I put it on the centre stand and put it into first gear and let the wheel turn under engine power then it seems to have a "tough spot" that it hits once per revolution and you can hear the engine "chugs" in sync with it. The chain does have a slight skip at this point so I'm inclined to think that it's riding up a tooth slightly and then dropping back down again, but I've retensioned it does the same thing.

Video of the issue under engine power: https://vimeo.com/171949938

I should point out that the bike has had two issues in the drivetrain in the past. On the day I bought it, the chain snapped and flew into the front sprocket housing. I think this was a combination of old chain and overtensioning.

On a more recent occasion a nylon strap got caught between the swingarm and the back sprocket and melted into a lump. I cleared it out and it seems fine otherwise. The problem occurred before this.

Any ideas? Hoping it's something I can just live with tbh!

[tom_e]

Check your chain for tight links before you end up with another case of it pinging off and wrapping itself round your front sprocket or worse.

[jaffa90]

Did you replace the sprockets when replacing the chain?

[hollisharri]

Yes jaffa90, bought sprockets and chain as a kit.

I think you guessed it tom_e, thanks - I took the chain off and felt all the links. All fine except the master link. Gonna get a new one and see if it makes a difference.

Just as an aside, Idled the bike with the chain off and the irregular chug is unrelated to the wheel issue.

[jaffa90]

Is it a split link or a rivet link and does it have seals?