Chain falling off front sprocket

[asc99c]

Hi all,

I've finally gone and bought an electric bike, a Cube Reaction with the Bosch system, which arrived yesterday. Unfortunately i only had time to set it up before taking kids to dancing and was 9pm after I'd got them all in the bath and to bed...

So after a very short test ride in sub zero temps last night. Everything is working great except twice the chain fell off the front sprocket, dropping and jamming up between the sprocket and the frame.

With no front derailleur, there's not really anything to adjust around there. Is there any likely cause of that sort of problem?

Andy

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[brightonebikes]

Hi all,

I've finally gone and bought an electric bike, a Cube Reaction with the Bosch system, which arrived yesterday. Unfortunately i only had time to set it up before taking kids to dancing and was 9pm after I'd got them all in the bath and to bed...

So after a very short test ride in sub zero temps last night. Everything is working great except twice the chain fell off the front sprocket, dropping and jamming up between the sprocket and the frame.

With no front derailleur, there's not really anything to adjust around there. Is there any likely cause of that sort of problem?

Andy

Sent from my ONEPLUS A3003 using Tapatalk

Bent tooth on the chainring throwing the chain off?

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[Deleted member 4366]

Two possibilities I can think of: incorrect length chain or incorrectly set b-screw on the rear derailleur. Also check that the two derailleur hinges are working smoothly.

 

[asc99c]

Checked the derailleur tonight and couldn't see any problems, and went on a slightly longer ride with no further problems - except that I hadn't tightened the headset clamp bolts enough!

The difference in drive train efficiency between this bike and my old mountain bike is massive! Hit 32mph heading down a shallow-ish hill according to the display, very impressive, although a bit too fast for my liking!

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