chain coming of wisper 705SE

[eddieo]

My wife has started commuting on her wisper 705SE and loves it. This is her third week and the chain has come of once or twice a week. She is nearly as hopeless as me regards bike mechanics and if it was not for the kindness of other cyclists stopping to help her she would have been stuffed. I have shown her how to put the chain on and last night leaving work thankfully she managed on her own......

My question is:

why is the chain coming of? my 905 in over a year has never come of.......

 

[Wisper Bikes]

Chain

Hi Eddie

The chain, chain wheel and dérailleur are exactly the same on both bikes so I would suggest there is an alignment ajustment problem.

If you contact Norman at our service department or Aiden at ebikes direct they will be able to talk you through the adjustment or pop it into a local bike shop and they will cure it for you.

All the best David

 

[Mussels]

My question is:

why is the chain coming of? my 905 in over a year has never come of.......

Lucky man, sometimes mine comes off several times a day though normally it's only once a day. I can't go moaning to Norman though as I've fitted my own chain ring which doesn't have the special plastic rim around it.

 

[flecc]

A binding freewheel action can also cause the chain to come off when pedalling is stopped and then resumed for any reason. Try back-pedalling that bike by hand when stationary and if the upper chain run droops a lot, that's an indication that dirt around the freewheel is causing it to bind. If so, apply some thin oil between the rear of the freewheel and motor to free it up.
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[eddieo]

Thats the thing I have not a clue what a chain ring or a free wheel is

But will check if chain is dropping tonight when she gets back....I did think the chain kinda dips compared to mine. but will do as Flecc says tonight

 

[flecc]

The freewheel is the multi-sprocket at the back on the side of the motor Eddie. The chainwheel is the large toothed wheel at the front of the chainrun.
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[eddieo]

The freewheel is the multi-sprocket at the back on the side of the motor Eddie. The chainwheel is the large toothed wheel at the front of the chainrun.
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Gotcha!

when you say " a binding freewheel action" I've just had a look at my bike and the freewheel turns easily in reverse if I turn it with my fingers.

are you saying if my wife's has resistance this may be the problem? and all I have to do is oil that part?

A bit odd on a new bike though dont you think?

 

[flecc]

That would be odd in a new Wisper, though it sometimes happens on new unpowered bikes fitted with Shimano's plastic backguard. That won't be the case on the Wisper though. When it happens through dirt, its just an accumulation of dirt between the freewheel and the hub causing the freewheel to bind to the hub, and light oil thins out the dirt allowing it to flake away. But as you say this is a new bike that's most unlikely to be the cause.

Amongst possible causes are misalignment of the rear wheel, the chainwheel slightly buckled through receiving a knock, the rear mechanism not tensioning the chain sufficiently so it droops excessively.
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