Just done a conversion and need help with PAS

Hi, I converted my bike to an E-bike. I went with a front wheel, 48v and it certainly goes like the clappers when I use the throttle control. My problem is the Pedal Assist doesn't seem to work properly. When I pedal, the power comes in on each down stroke of the left pedal in short bursts. This doesn't seem to help all that much and I feel it should be constant. Is this a common problem or is this how it is supposed to work? I made sure the magnetic wheel is definately spinning with the pedals by glueing it in place so it's not slipping. Can anybody shed any light on it?

 

Thanks for any help,

 

Albion

Is the gap between the disc and the sensor constant, i.e. is the disc parallel to the sensor? It should be 1 - 3mm away.

Show us a pic of the set up on the BB.

A make sure the sensor is fixed correctly and static.

Hi, thanks for the coments. Yes, I made sure the distance is correct and that the it is not cockled over and is constant. It's new and grabs pretty good as far as I can see, there is no drag. I made a few adjustments today, though and made it a little better. The sensor was at the top and I moved it to the bottom which seems better. Now the burst is on my right foot and seems to work better. I cleaned everything up as well and it seems like the burst of power lasts a little longer. I'm still not sure this is the way it's supposed to work though. What do you think?

A generic PAS should power evenly throughout the crank rotation is doesn't sense left or right pressure (unless it is a TS PAS), what kit have you got and which sensor. It might be that you have an incorrect setting configured.

Check that all the magnets are present and check with another magnet that they're all the right way round. I have found one sensor with a missing magnet and one with an incorrectly orientated one. Both faults gave the symptoms you describe.

A long shot - is the bottom bracket knackered as in when you put pressure on the pedals, the cranks rock a little to left and right as you pedal which in turn might be increasing the distance between magnets/sensor?

Hi, thanks for your further coments on this . I really appreciate the feedback. I remember one of the magnets fell out and I just put it back in anyhow. I am now thinking this is the problem. I guess I need to need to put a magnet against each one in turn and find the one that repels rather that attracts. I've checked the pedals and they are tight and not wobly at all. I've been meaning to get a pic to you but not got round to it yet. I'll get on to it if this does not work.

 

Thanks all

Wow, it works! There were 2 magnets that were the wrong way around. I just tried it and it rotates indefinately at a constant rate now when I pedal. I probably wouldn't have thought about this and was on my way to buying another PAS. Thanks fvr400, and the rest of you for all your suggestions. When it stops raining I'm goint to try it out on a big run.

 

Cheers, Albion.

Another happy ending. Big sigh of relief!