Drive chain slack

zscr · 01-01-2022, 07:56 PM

A couple of weeks ago I purchased a Zongshen bike, one of the fairings says ZS250GY-7 as the model, it’s very similar to CSC tt 250 but with basic suspension and the wheels are 19f-18r.
When doing the first service to the drive chain(428h no orings) I measured a big difference between the tightest points and other parts of the chain. So my manual and swing arm call for 25mm free play, the tightest points were at 25mm and the loose points were at 45mm.
I thought it was because the chain was low quality so I bought a DID chain and installed it and when adjusting the slack I got almost the same measurements, 25mm at tightest and 40mm on loosest. Can this be a bad sprocket? Or is this normal even with a new chain? My only point of reference is my other bike which is a cbr250r and the slack is normally 5mm between points.

01-01-2022, 07:56 PM	#1
zscr Join Date: Dec 2021 Posts: 7	Drive chain slack A couple of weeks ago I purchased a Zongshen bike, one of the fairings says ZS250GY-7 as the model, it’s very similar to CSC tt 250 but with basic suspension and the wheels are 19f-18r. When doing the first service to the drive chain(428h no orings) I measured a big difference between the tightest points and other parts of the chain. So my manual and swing arm call for 25mm free play, the tightest points were at 25mm and the loose points were at 45mm. I thought it was because the chain was low quality so I bought a DID chain and installed it and when adjusting the slack I got almost the same measurements, 25mm at tightest and 40mm on loosest. Can this be a bad sprocket? Or is this normal even with a new chain? My only point of reference is my other bike which is a cbr250r and the slack is normally 5mm between points.
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