Cytronex motor prob

Rowlandsbond

Just Joined
Jul 16, 2016
2
0
57
London
Hi all I'm new to this ebike lark, having bought a cytronex merida t3 second hand. Was enjoying it enormously but suddenly the power seems to have vanished. The motor spins if the bike is off the ground. But when I'm riding I can hear a noise as if the motor is running but there's no noticeable assistance. If I turn the pedals with the bike off the ground the front wheel spins, but if I slow it with my hand it takes no effort to stop it spinning and it judders...

Any thoughts would be most appreciated.
 

oldtom

Esteemed Pedelecer
Hi all I'm new to this ebike lark, having bought a cytronex merida t3 second hand. Was enjoying it enormously but suddenly the power seems to have vanished. The motor spins if the bike is off the ground. But when I'm riding I can hear a noise as if the motor is running but there's no noticeable assistance. If I turn the pedals with the bike off the ground the front wheel spins, but if I slow it with my hand it takes no effort to stop it spinning and it judders...

Any thoughts would be most appreciated.
There isn't really a lot goes wrong with the Cytronex system but if it's outside the scope of your electro/mech ability, I'd suggest you book it in with the guys down at Winchester who can usually resolve issues and turn the bike round, ready to ride again in a couple of hours or so. It's a pleasant place to walk around if you've never been there and doesn't take too long to get to from the London area.

Before doing that, you might wish to check the connections as far as you are able and examine the sensor position and gap on the front wheel/fork - it's easily knocked out of alignment. The little Tongxin motor doesn't like rough terrain but should it be a motor failure, they have the internal parts in stock and can do that work very quickly. The battery, if it is not accepting charge properly, (perhaps a faulty charger), can also cause weird behaviour but I'm sure you would know if it isn't charging from the charger light display.

The position of the controller is questionable as it can easily allow moisture in past the seals when they become aged. Moisture ingress can cause strange behaviour of the kind you report but the guys at Winchester have dealt with all the faults likely to occur on their system and repairs are relatively inexpensive.

Best of luck,
Tom
 
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Rowlandsbond

Just Joined
Jul 16, 2016
2
0
57
London
Hi tom, thanks very much for the advice. The battery seems OK and sensors all look fine. So I guess it's motor or controller! Thought I'd check if anyone recognised the problem before going down Winchester way.

Thanks tho!
 

oldtom

Esteemed Pedelecer
The battery seems OK and sensors all look fine. So I guess it's motor or controller! Thought I'd check if anyone recognised the problem before going down Winchester way.
Your symptoms sound very much like those I experienced after my other half rode her bike through a rather deep ford. It was fine all the 4 miles home and the bike was then unused for about a week but on taking it for another ride, the problem manifested itself.

I managed to work out that it was probably the controller and on opening the box, a fair bit of water ran out. No amount of drying with rice, hairdryer or tissue corrected the fault and I figured it was probably easier to drive to the experts and let them fit a new controller rather than attempt to locate a suitable replacement and get amongst the 'spaghetti' to hardwire it into place. I'd never been to Winchester before and I really enjoyed walking round the place.

The bike was left at their workshop late morning and they called me early afternoon to say it was sorted.

Tom