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Author Topic: Drive Chain Oscillation under load, why?  (Read 1142 times)

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Offline cb550fcafe

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Drive Chain Oscillation under load, why?
« on: October 13, 2021, 10:06:15 AM »
my drive chain on pull side will begin to oscillate violently during a dyno pull, it was so bad it looked like I had 4 chains. Then while racing I was feeling that vibration at that rpm band. It only gets bad in the upper RPM range above 6,000.

This is a race bike, only race miles. I clean the chain often, its non o-ring, standard gold chain from Rebel, Rebel sprockets, all in good condition, in alignment, proper adjustment. This is 3rd race season on chain, maybe its time to go? 45hp bike.
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Offline Old Scrambler

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Re: Drive Chain Oscillation under load, why?
« Reply #1 on: October 13, 2021, 10:54:41 AM »
Very likely loose pins and/or worn sprockets ;)  Racing just a few miles is still expensive ;)
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Offline Tracksnblades1

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Re: Drive Chain Oscillation under load, why?
« Reply #2 on: October 13, 2021, 02:44:38 PM »
What size front sprocket?

Are you running a Cush drive..?
« Last Edit: October 13, 2021, 02:46:52 PM by Tracksnblades1 »
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Offline cb550fcafe

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Re: Drive Chain Oscillation under load, why?
« Reply #3 on: October 14, 2021, 04:08:55 AM »
Quote from: Tracksnblades1 on October 13, 2021, 02:44:38 PM
What size front sprocket?

Are you running a Cush drive..?

16t front, yes stock CB wheel with cush.
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Offline bwaller

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Re: Drive Chain Oscillation under load, why?
« Reply #4 on: October 14, 2021, 10:57:12 AM »
Change it more often, I tossed them after four weekends, and by then they're toast. As chains stretch they wear sprockets, especially aluminum.
 
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Offline Tracksnblades1

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Re: Drive Chain Oscillation under load, why?
« Reply #5 on: October 14, 2021, 10:10:41 PM »
Quote from: cb550fcafe on October 14, 2021, 04:08:55 AM
Quote from: Tracksnblades1 on October 13, 2021, 02:44:38 PM
What size front sprocket?

Are you running a Cush drive..?

16t front, yes stock CB wheel with cush.

I’d probably follow bwaller’s advise…

I personally don’t like smaller than stock front sprockets. I think the engineers had chain harmonics and turn radiuses in mind  during design and testing. I prefer the rear sprocket to make permanent final drive ratio changes..

I personally have had good results with RK and Regina chains. My old 76f still wears the OEM Chainguard decal indicating the RKChain Honda used back then.. We use the Regina 520 on our CR500R and CR250Rs smokers and just ride ….😇

But you’re racing so you’re not going to get extended life out of any components..😜

« Last Edit: October 14, 2021, 10:12:14 PM by Tracksnblades1 »
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Offline bwaller

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Re: Drive Chain Oscillation under load, why?
« Reply #6 on: October 15, 2021, 07:00:29 AM »
We are only able to use 16 or 17T fronts on these engines.
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