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Old 10-14-2009, 07:53 PM
wildemere wildemere is offline
Motorized Bicycle Elite Member
Join Date: Feb 2008
Location: Newcastle
Posts: 269
Default Re: Chinese Bicycle Motor - Bearing Part Numbers

Just get a new crank unless you have a 20t press and associated jigs to rebuild it.

I guess its the big end bearing cage which has disintegrated into your metallic mud.

The rollers are still present but the cage is gone.Unfortunately this bearing is hard to source and change.

Anyway, give Warren at ZBOX a call he may have a crank.

MBB Imports has the oil seals the other 4 bearings are stock items at CBC or other bearing suppliers. Get Japanese ones.

Stihl have a nice top-end bearing that fits these needle bearing motors. P.N 9512 003 23

Just remember these motors are junk, no retainers on bearings, no dowel pins anywhere.

So the end float on all critical parts is hit and miss, they sound and run different each time you start them.

Some run better than others, I find the older bushing motors run best. I have a 2 year old ZBOX that has done 100km a week sometimes. Others have grenaded in 2 months. Some pull 60 kmh with a 35t sprocket. others struggle to get over 45.

But I still like 'em. Just get 2 bikes and 3 or 4 motors and you cant go wrong.

I've commuted and relied on these stupid things for 2 years now. I tried the turd polishing for a while then realized it was pointless. Get a second bike then repairs happen when you want to do them.

At this time I have three bikes, the "champion shifter bike" (weekends only) as they are inherently unreliable, (3 chains and 2 freewheels) but it pulls 70+ kmh.

Then 2 single speeders for work and back.
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