New controller and motor needed

[mxer]

Hi all,

I need a new front motor and controller as it seams the motor has gone on my wife's abike.

It's a 36v 8fun 3 pin motor (cuts out under pressure).

The bike has no display with Pas and traffic light throttle.

I'm thinking of replacing the front wheel and controller to match the new motor.

Any ideas if where to buy one? Or links to my needs.

Many thanks in advance..

 

[Nealh]

Hi all,

I need a new front motor and controller as it seams the motor has gone on my wife's abike.

It's a 36v 8fun 3 pin motor (cuts out under pressure.

How old is the battery ? As your description of cutting out sounds like voltage possibly collapsing.
Hubs don't usually work or not there is no in between.

 

[Kwozzymodo]

I think I have a Q100H and a Q85 available - depending on axle width requirements.

 

[Benjahmin]

I would agree with Nealh. If the motor works at all then it's probably OK.
If the battery is near end of life (or has some damged cells inside) then it would behave exactly as you say. It would provide voltage until it comes under load when it can't deliver the current needed, so the voltage goes down and the low voltage cutout (lvc) in the battery management system cuts in, which stops everything from working until voltage recovers.
Save yourself some uneccesary expenditure and measure the battery voltage hot off the charger. Then measure it again after cutoff.
Cheapy digi volt meters can be had for a fiver.

 

[Nealh]

Mxer you need to temporary wire up a cheap volt meter to see what happens to the voltage, as all been said when a load is asked of the battery and it can't cope with the load demand the voltage collapses or sags very badly.

 

[Deleted member 25121]

I agree with the suggestions above, measure the battery voltage when the motor stops. Also measure the voltages on the motor's pins, it could be the controller that's faulty.

 

[Andy-Mat]

Mxer you need to temporary wire up a cheap volt meter to see what happens to the voltage, as all been said when a load is asked of the battery and it can't cope with the load demand the voltage collapses or sags very badly.

The drop in voltage will probably ONLY be seen when riding, which makes for the owner, a bit of a problem to wire up, but still exceedingly important to do.
May I suggest making up a Red/Black pair of wires to the battery, with meter plugs (cheap on ebay) on the other end.
Then mount the meter on the handlebars using sticky tape, as a clamp may damage the meter...
If the front light is supplied by the battery directly, as many are nowadays, that could possibly be an easier place to monitor the voltage from....
Andy

 

[Nealh]

Voltage drop can be done statically if a throttle is used or by using the PAS system, the load can be applied by gentle brake pressure applied. Using the PAS may be esier with someone else to help.

 

[mxer]

Thanks all, I think I may have sorted it.

Had a poor battery connection, would disconnected under load by the looks of it, I have reworked the connections tight with no movement.

Time will tell if it's cured the intermittent cut out. Fantastic community can't thank you all enough

 

[mxer]

Oooo may still be interested (price dependant) on a new front motor if laced into a 26" wheel?, mine is 3 pin 100mm drop outs Pm me a price.