really bad "chain slap"?

[kmcneill]

Hi
I've got this issue with my drivetrain that is just driving me nuts.At low end (up to around 15 mph), I get quite a bit of what feels like chain slap ...which tends to smooth itself out at higher speed. as far as I can tell, everything is aligned and chain tension is correct. This issue is so severe t times, however, that I've had to replace the hawthorn key. Does anyone have any idea what is causing this, or how to rectify it? Thanks.​

 

[FurryOnTheInside]

Worn out "stretched" chain,
literally stretched kit chain,
worn out or badly made sprockets,
eccentric sprockets,
lack of proper chain tension,
long spans of unsupported chain..


What's a hawthorn key? Is it a woodruff key?

 

[kmcneill]

yes, I meant woodruff. key ...sorry

chain tension s good
only about 3 hours on the chain
what do you mean by eccentric sprockets?

 

[crassius]

these don't go slow very well - riding thru a parking lot, I'll slip clutch a bit to get to speed, then coast a bit then repeat

eccentric sprocket - is when it isn't aligned in the up/down so that chain gets tight then loose as the wheel turns

 

[FurryOnTheInside]

The kit 10T engine sprocket has very square topped teeth, the corner of which can lift the chain so it fails to feed onto the sprocket smoothly, and it can also hold into the chain making it fail to feed off the sprocket smoothly.

Observe the chain going onto and coming off the front sprocket, preferably under power though if there's a problem there you'll probably see something even if you just spin the wheel.


The kit 10T sprockets are all eccentric. The hole is not in the centre. That's a separate issue to the tooth profile. You can't fix the eccentricity by grinding and filing the teeth.

 

[kmcneill]

these don't go slow very well - riding thru a parking lot, I'll slip clutch a bit to get to speed, then coast a bit then repeat

eccentric sprocket - is when it isn't aligned in the up/down so that chain gets tight then loose as the wheel turns

these don't go slow very well - riding thru a parking lot, I'll slip clutch a bit to get to speed, then coast a bit then repeat

eccentric sprocket - is when it isn't aligned in the up/down so that chain gets tight then loose as the wheel turns

Haven't thought of that ...thank you I'll check

 

[kmcneill]

The kit 10T engine sprocket has very square topped teeth, the corner of which can lift the chain so it fails to feed onto the sprocket smoothly, and it can also hold into the chain making it fail to feed off the sprocket smoothly.

Observe the chain going onto and coming off the front sprocket, preferably under power though if there's a problem there you'll probably see something even if you just spin the wheel.


The kit 10T sprockets are all eccentric. The hole is not in the centre. That's a separate issue to the tooth profile. You can't fix the eccentricity by grinding and filing the teeth.

I have a centrifugal clutch ...any slow-go suggestions for that?

 

[FurryOnTheInside]

I have a centrifugal clutch ...any slow-go suggestions for that?

Idk, I don't have one of those.
Pedal?

 

[crassius]

simplest would be a larger sprocket on rear, but that would cost you in top speed