hard core chain vibrations

bairdco

a guy who makes cool bikes
Aug 18, 2009
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living the dream in southern california
go slower?

just kidding.

it's pretty normal for the chain to be going crazy at top speeds. if it seems like a lot swingin' action happening, make sure your sprocket is straight and true and that there's not too much slack in the chain.
 

The_Aleman

Active Member
Jul 31, 2008
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el People's Republik de Kalifornistan
Yeah, it's somewhat normal, and if you're running a master link it's almost inevitable. Also, if you're using the idler that came with the kit, you might want to upgrade to a true chain tensioner, as the kit idler is just that - an idler, or a guide. It is not a true tensioner.

Something like this: Chain Tensioner - Kore Black - Cycles U.S. LLC/Choppers U.S.

Also, make sure your chain is lubed and you have no stuck links. If you "broke" the chain yourself using tools, then make sure you don't get any sticky links. Excessively worn chains will rattle more, as they simply have more play. Expect to replace a chain every 500 or so miles, depending on the initial quality and how well it's treated during use.
 
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thrasher666

New Member
Jun 24, 2021
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Man Ive been having same problem.I get this vibration at 25mph. Sometimes itll even stahl the motor a little then it will smooth out at30+mph.I put a spring tensioner on and that made it worse .So now Ive taken tensioner off and run it without one and that made a big difference but still didnt solve problem.So is this a "un-ballanced crank issue? Does anyone know?
 

MEASURE TWICE

Well-Known Member
Jul 13, 2010
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CA
I do not have a 2 stroke bike or kit, but with how you mention that after passing 25 an reaching 30 an above vibration is less or gone, there is this. Once with a car I had a heat shield on a muffler that a 50 it would rattle and above it was gone. I found the crack in the shield and replaced it Problem gone for a while. It is called sympathetic vibration due to resonance. The reason it happened after I replace the cracked part was it cracked again. Maybe inferior part manufactured or that the bolt hole were not drilled right and caused stress and cracked the part and would continue to. Ah and I noticed this is continuation of an old thread, though others might know something Anyway thin sheet metal that is not secure is possible, chain I don't use have a belt. A short piece of chain I have on a DIY build that is from clutch to jackshaft only.