Agattu chain adjustment

[Citrus]

Hi,

I have some drivechain noise from my Agattu (just over 500 miles usage). I am trying to find out what the cause is - I have adjusted my hub gears which were slightly out and cleaned the chain and sprockets. I noticed that the chain tensioner (I think that's what it is) is spring loaded and was sticking slightly - so I cleaned everything and slackened the bolt a fraction. The question is should this bolt be slack or tight? Advice gratefully accepted. BTW the gear change is fine.

 

[flecc]

It should normally be moderately tight, since the rotation doesn't depend on any slackness there. That spring loaded idler isn't critical in fact, since there are no sensors reading from it, it's merely there to provide sufficient wrap around for the chain on the motor drive sprocket.

It's very difficult to attribute a cause of a noise without knowing it's nature. Does the sound have a grinding or rubbing nature as far as you can tell?
.

 

[Citrus]

Thanks Flecc

The noise was a rhythmic grinding noise when peddling only - not too loud but annoying. It turns out it was that tensioner - the bolt was slightly loose and I slackened it more thinking that the spring self-tensioned the chain somehow. I have now re-set it and tightened the bolt moderately tight as you suggested and the bike is now silent again in all gears - the noise must have been the chain jumping because of the slack I assume.

 

[flecc]

That's good. These things sometimes do take a little while to settle, just running in basically. The next time you hear something like that might be years away now, when the motor sprocket wears out. Easy to fix though.
.