ChinaRiders Forums - View Single Post - New Zongshen RX3 (ZS250GY-3) Dual Sport

katflap · 03-01-2015, 12:21 PM

* RX3 WITHOUT CUSH DRIVE HUB *

I can confirm that the JTR 897 44T rear sprocket fits the NON Cush drive hub of the RX3 but does require counter sunk sprocket bolts and centralizing on the hub. “Well it doesn’t fit then” I here you say, well it fits better than the original sprocket!

I was having trouble getting rid of a massive tight spot on the drive chain and found that the bolts to sprocket and hub holes are a slack fit and that the inner sprocket diameter to hub lip was also a loose fit, causing it to run off centre.

By wrapping around the hub lip twice with electrical insulation tape I was able to centralise the sprocket on the hub. This improved the tight spot but was still not good enough, then fitted a new D.I.D O-ring chain with the same result.

On with the new sprocket, this needed only one wrap of tape around the hub lip to create a snug centralised fit.
Bingo! , I was able to adjust the chain without getting wild variations in slack, now well within normal limits.

Took the bike for a 10 mile spin, what a difference, much smoother at low RPMs and gear changes and no chain slap / chatter. Much nicer to ride at slower speeds.

I guess the original sprocket wasn’t well made.

The bike is now close to perfect!

03-01-2015, 12:21 PM	#2278
katflap Join Date: Jan 2015 Location: England Posts: 382	Rear Sprocket (Non cush drive hub) * RX3 WITHOUT CUSH DRIVE HUB * I can confirm that the JTR 897 44T rear sprocket fits the NON Cush drive hub of the RX3 but does require counter sunk sprocket bolts and centralizing on the hub. “Well it doesn’t fit then” I here you say, well it fits better than the original sprocket! I was having trouble getting rid of a massive tight spot on the drive chain and found that the bolts to sprocket and hub holes are a slack fit and that the inner sprocket diameter to hub lip was also a loose fit, causing it to run off centre. By wrapping around the hub lip twice with electrical insulation tape I was able to centralise the sprocket on the hub. This improved the tight spot but was still not good enough, then fitted a new D.I.D O-ring chain with the same result. On with the new sprocket, this needed only one wrap of tape around the hub lip to create a snug centralised fit. Bingo! , I was able to adjust the chain without getting wild variations in slack, now well within normal limits. Took the bike for a 10 mile spin, what a difference, much smoother at low RPMs and gear changes and no chain slap / chatter. Much nicer to ride at slower speeds. I guess the original sprocket wasn’t well made. The bike is now close to perfect!
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