Bosch. First real problem

Gubbins

Esteemed Pedelecer
After my chain episode I thought I would bend the chain guard in a bit to remove the gap on the left hand side so started to take off the chain-ring...
There is an obvious gap which is where the chain went down, but I am alarmed to find there is play on the spider flange! (big silver nut in photo) There is no play on the cranks, but definite movement on the chain ring. You can see where the chain has scraped on the casing when it jumped off.
I hope this isn't a terminal problem, so any advice here is welcome....
Thanks..
 

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Artstu

Esteemed Pedelecer
Aug 2, 2009
2,420
925
Mine wobbles too, it has done from new, I had just thought they were all like that. It'll be interesting to see if they're all like that.
 

flecc

Member
Oct 25, 2006
53,203
30,604
These crank drive units have of necessity a freewheel on the chainwheel, allowing the crank arms and pedalling to be independent of the motor driven chainwheel. That means some lateral slack (wobble), it's true of all of them right back to the earliest Panasonic crank unit.
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Gubbins

Esteemed Pedelecer
When I have the bike on a stand I remove the battery because of the weight. So, refitting the chain I dropped half a powelink down in the bottom battery bracket.. Dumb or what? Taking it apart seemed the only way and hey presto... The bracket is adjustable! No more battery becoming dislodged on the rough stuff. Wish I had known at 12 months ago..... I wonder if that might help others having battery fastening issues.