Help needed - emotion panasonic 2010 bike

[badpoet]

Hey all,

I am wondering if anyone can help out, I have had my bike serviced and they suggested replacing the rear main cog and a couple of other due to wear.

I have got the bike back and unpowered it's running fine, but under power it's pulling the chain around the drive cog which then pulls the rear derailier tight. This then pulls back straight unwrapping th chain from the drive cog.

Any suggestions on what this may be?

All help appreciated!

 

[HarryB]

Did they put a new chain on? Should have done anyway if replacing the sprockets. It is possible that they got the chain path wrong even if this seems unlikely.

 

[badpoet]

Sorry I didn't mention, yes it was a new chain as well. The path looks ok, how would you have thought they have done it wrong?

 

[badpoet]

Jus been and checked th chain layout and it looks the same as on fleccs website

 

[flecc]

If they've rivet joined the chain, the link join might be too tight and that would corrupt how it follows the sprockets. Check to see if one of the joins is tight and not rotating freely.

The other possibility is that the motor sprocket teeth are wear hooked and not releasing the chain due to the hooking of the teeth, though this is unlikely.

However, best that you ask them to put it right, since it's unlikely it's the fault of the motor unit, only the bike parts they've worked on.
.

 

[badpoet]

I have checked the motor sprocket and it doesn't appear hooked as you describe but might order a new one anyway.

Its odd as the chain appears to be moving freely with or without power but when powered it just gathers round the cog right away as soon as the motor kicks in.

I have contacted onbike to see what they suggest, its a 2 1/2 trip to them unfortunately though if i need to take it back - my local bike shop is clueless about electric bikes they just serviced the noraml bike components.

 

[RussJ]

Could it be they've installed the wrong size chain?
If the chain is wrapping itself around the drive cog under power, it suggests the chain is jamming on the teeth when the extra torque is applied and the teeth are forced into the chain...

 

[badpoet]

do you think this would still let it run fine without power?

 

[banbury frank]

Hi

I would suggest you Buy from onbike the rear cog and motor cog and chain and have the bike shop fit them .

If you want reliability always use original parts .

Go to onbike and ask if they can fit while you wait .

This is the only problem with motors that drive via the rear chain and gears . But it is wear and tare like a clutch in a car NOT A fault

the chain and gears wear out with a rider pedaling on a normal Bike

Frank

 

[flecc]

Badpoet, is it the single follower or double follower wheel in the tensioner?

 

[badpoet]

Its the single one on mine. Onbike have suggested flipping the drive cog to see if that makes any difference.

 

[flecc]

That's the trouble in part. The newer double one isolates the derailleur rear mechanism much better. Reversing the drive cog as I suggest on my site only applies if it's hooked a bit, but worth a try anyway.

The other things to check are:

The 65 mm spacing as shown on my site, this set by the chain tension.

Whether the rear mechanism tension is adequate to maintain that 65 mm.

The free running of the idler wheel in the tensioner, they can bind and cause this problem.

Whether the pivoting of the unit's tensioner arm is free. There have been a number of incidences of this binding and failing to wrap the chain correctly on it's path.

 

[badpoet]

the wheel in the tensioner seems to run pretty freely, the arm itself has a small amount of play in it but not a great deal - i would say its only moving a few mm`s. How much pivot should the arm be able to do?

The distance seems ok, i measured that last night and from the centre of each wheel it is around 65mm.

 

[badpoet]

i am going to try and get a picture tonight if none of the above helps as i may not be explaining the issue very well

 

[flecc]

You are explaining it fine, I've got the picture ok.

The arm doesn't have to move other than being free to take up momentary slack, since it's not so much a tensioner as a wrapper, hence that fixed 65 mm recommendation.

Since those points are ok, not many possibilities are left. The rear mechanism spring tension could be so slack that it's falling to pull on the chain sufficiently. There's the possibility of a wrong chain as someone mentioned, a narrow 9 speed one rather than the 7/8 speed, though this seems unlikely.

I'd say start by reversing the motor sprocket to present the unworn tooth face to the chain links. That could well cure the wrapping around problem.

 

[HarryB]

On the emotion the idler arm is not sprung as in the Kalkhoff so it is difficult to see how this could cause the problem if the path is correct. As Flecc says the tensioning is all done by the derailleur. If the chain and sprockets are worn out then it is almost certain that the drive sprocket should be replaced or reversed. Normally you would get some clicking on power in this situation - you will get this even if the sprocket looks unworn to the eye. I think this is the most likely problem as your chain and sprocket would have worn together - only when you change one do you get a problem.

 

[tillson]

I haven't replaced any of the drive components on my Panasonic setup as yet, but when I do, I will replace everything together, chain, rear sprocket, drive motor sprocket and chain wheel. Given the relatively low cost of these items and their longevity, I don't understand why people mess around changing certain elements of the drive. Just renew the lot.

My drive is very heavily worn. I can see very obvious hooking on all of the sprocket teeth. But, everything has worn together and it still works, no slipping. My plan is to continue until something fails.

 

[badpoet]

I was getting a new drive cog it just hadn't been ordered, it isn't a standard part so the shop didn't have one.

Good news on reversing the cog - we now have lots of sweet power at least for a couple of days until the new cog arrives. After buying some circlip pliers it was an easy task and worked straight off, it still doesn't really look visibly worn but it must be.

So after ten days back to cycling to work at last!

Thanks fo the help everyone.

 

[flecc]

Glad it's ok now. It will be for longer than a couple of days though, it should run just as long in the reverse position as it did originally. As Harry and Tillson say, changing everything together is always best.