Author Topic: Chain Problem (Read 3041 times)

banditcilik · « **on:** September 12, 2005, 07:52:31 AM »

My B4 emitting strange noise when it rolls. Sounds like it comes from the chain. At slow speed it sounds like rattles and change to a hum at hi speed. I inspected the chain and no metal contact with chain. The rubber pad seems OK to me. Is it possible the rubber pad hardened and make a loud contact noise with the chain?

Maniac · « **Reply #1 on:** September 12, 2005, 08:33:11 AM »

How do the sprockets look?

todius · « **Reply #2 on:** September 12, 2005, 11:48:54 AM »

Quote from: "banditcilik"

My B4 emitting strange noise when it rolls. Sounds like it comes from the chain. At slow speed it sounds like rattles and change to a hum at hi speed. I inspected the chain and no metal contact with chain. The rubber pad seems OK to me. Is it possible the rubber pad hardened and make a loud contact noise with the chain?

Is the chain rubbing on the rubber pad? If so, it sounds like it's too loose. A properly adjusted chain should ride just above the pad (you should see an air gap between the rubber pad & chain) .. bottom of the chain should wiggle up and down about an inch-ish.

Also check for tight spots in the chain (where the chain is kinked and it won't bend easily). If there are any tight spots, clean the chain really well with kerosene or WD-40 to free them up. Also, as stated above, check the sprockets for bent, worn or missing teeth.

A third common cause could be a rear sprocket that is not alligned properly with the chain.

PitterB4 · « **Reply #3 on:** September 12, 2005, 12:15:52 PM »

This might be a comment for:

but... it might be easier to pinpoint/diagnose if you got down there with the bike on the center stand and listen while rotating the wheel.

Maniac · « **Reply #4 on:** September 12, 2005, 12:30:55 PM »

Quote from: "PitterB4"

while rotating the wheel.

By hand! BY HAND! Don't do this with the engine running in gear!

Fingers come off really easy when caught in a chain and sprocket, not to mention there is always the possibility of the bike vibrating off the centerstand and taking off down the road.

PitterB4 · « **Reply #5 on:** September 12, 2005, 01:27:42 PM »

Well yeah, by hand. Besides, you can hear the chain better w/out the motor running.... (I never thought of someone doing it with the motor.

)

Maniac · « **Reply #6 on:** September 12, 2005, 01:32:25 PM »

Quote from: "PitterB4"

(I never thought of someone doing it with the motor. )

The guy next door when I lived in Michigan did, lost his thumb.

They reattached it though, but really, the kid wasn't right...

banditcilik · « **Reply #7 on:** September 15, 2005, 03:26:20 AM »

Whoa that's so scary, imagining someone stuck his fingers between chain and sprocket. Thanks for the reminder.
I looked through the drivetrain again and yes the chain touches the rubber pad. I made this set up because if I fasten the tensioner until chain is floating then the play on the chain's half bottom is very little. Also the noise become worst.
Noise sounds coming from prymary gear area and it sounds in different tone when I turn the wheel at opposite direction.

Maniac · « **Reply #8 on:** September 15, 2005, 08:57:42 AM »

I'd pull the cover and check the teeth on the sprocket, chances are they are cupped (bent) and are catching the chain.