KMX + Cyclone chain problem

[ballparkcy]

Hi everyone,

This is my first post on the forum so go easy on me. Sorry it's a long boring techie one

Through a lot of inspiration I have decided to build a e-trike for some recreational fun at weekends. Having a very tight budget I ended up with a KMX ST class 2nd hand [barely used] and a Cyclone 500w kit [brand new] with LIPO4 batteries.

I know the cyclone is not favoured by many and if I had unlimited cash would have a puma hub, blah blah blah...anyway maybe for the future....

My issue at the moment is chain derailing. I have installed the double-free wheel kit at a recommended location, made up a free-wheel to insure the chain-line at the bottom is as near to the original and shortened the chain accordingly.

What I am experiencing is the chain jumping off the main drive sprocket under heavy throttle only in a highish gear, maybe 4-7. You can full throttle OK in 1st and 2nd, 3rd sometimes jumps.

Do I need an additonal sprung-loaded tensioner or maybe a shorter chain ? Before anyone asks the KMX had been used 3 times before I got it so there is no wear on any of the drive-train components, cyclone of course is brand new. I have also checked for tight links after I rejoined the chain, none that I can find.

My tests so far only in 1st and 2nd seem impressive! Pick up speed is great! and the KMX handling is amazing...

So I am not really up to any more test piloting until I can resolve this issue. Im sure it can't be too difficult to sort..

I've included a picture so anyone can see how the motor is fitted.

Any ideas greatly appreciated,

Regards,
Ballparkcy

 

[flecc]

That distorted chain path is probably as much responsible as anything else, since the twist is over a very short run. I think maybe an extra spring loaded idler, possibly giving a correcting lateral bias to stabilise the chain could do the trick.

Alternatively, a polished guide plate to steer the chain back into line when it jumped might work, but that depends on how severe the drive snatch would be.
.

 

[ballparkcy]

flecc,

Cheers for the pointer...

Regards,
Ballparkcy

 

[flecc]

Pleasure ballparkcy, and apologies. I meant to say welcome to the forum, but here it is belatedly.

Hope that suggestion works, but let us know how you get on either way. I'm not a Cyclone fan for the usual reasons, but a recumbent trike application suits it better than a normal bike one I think.
.

 

[Jeremy]

There doesn't look as if there is much wrap around the motor sprocket from the rear chain, which might be part of the problem. Is is possible to move the lower guide sprocket further back? Alternatively, an extra guide sprocket, arranged to put an "S" in the section of chain between the motor and the lower guide sprocket might help.

Jeremy

 

[ballparkcy]

Jeremy,

Thanks, I have ordered a KORE tensioner to cannabilise. Hopefully rig up something at the w/end to see if it cures it..

Will post back with results..

Cheers,
Ballparkcy

 

[ballparkcy]

Finally had time to fit a KORE tensioner! Anyway, it has seemed to correct the problem, no more chain derailing although I have only been a short distance. Hopefully if the weather improves I might take it out to see if I can exhaust the batteries completely! and maybe record the mission on film.

Regards,
Ballparkcy

 

[kraeuterbutter]

yes please !! a little movie would be very nice !

 

[paultrafalgar]

Hi everyone,
...
I've included a picture so anyone can see how the motor is fitted.
...

Looking a the left hand edge of your photo I am puzzled. The chain appears to end and be zip-tied to the frame!? Does it go under the cross-member or what? Usually a picture is worth a 1000 words, but not this one

 

[ballparkcy]

The picture is not all that clear...sorry.

The chain passes through a chain-tube which passes through the front frame-cross member..The cable tie just stops the tube from moving, not exactly high tech, but that's how it is designed by KMX.

Strange design but seems to work very well. I think on the MK2 KMX they have greatly improved on this and have a freewheel to move the chain up and over I think....

Anyway, my problems are over with the 3rd party tensioner now fitted. I have been meaning to get a video together but having made a decent mount have found the video to be unwatchable, too much vibration..So have not had time to remount maybe on my helment + the weather down here in the SW has been really bad...

Anyway, only 1 1/4hrs to go [lunchtime here] and Im off down Lidl for some cheap bike bargains!!!!!

Cheers,
Ballparkcy