Hi
Ok if you keep the motors to the rated power 350 or 500W then you wont have any problems at all, the problem comes when you move towards 1KW or above and of course how you use the motor.
At just 48V 35A it is possible to quickly wear the planetary gears with hard acceleration, this of course inst unacceptable as the motors are not rated for this power use, that said they can be made to take the increase in power.
Another thing that can happen is the free-wheel body slips on the main inner drive gear, this can be fixed simply by dropping 4 blobs of weld on to the rotor and drive gear, I did this on mine only to have the gears wear about a month later.
On my old school Puma (BMC Really) the gears have worn some and are slipping, from a dead stop if you open the throttle you go nowhere, if you go easy its fine and doesn't slip, I haven't had this motor apart nor am I too worried as I just peddle from the start and go gentle on the throttle (none of my other Pumas have done this).
The free-wheel can easily be removed, you need to use a long armed crank puller, like this one
Once off you can flip the thing over, undo all 3 x circlips and remove the Nylon gears, these are pressed in to bearings, it would be easy to find the same gears in metal and get new bearings pressed in to them, this would of course make the drive more noisy but it would never break, whilst you have this removed it would be a good idea to weld the crank at the same time.
For sure the new Puma controller is better on the Pumas and is designed to run with motor, the xlyte can be used but it seems a little hit and miss on certain controllers and at certain voltages, I have never heard of any problems at 48V but 72V can be a problem as we know.
Another thing people don't need to worry about gear failure jamming the motor, if all gears fail and jam, the free-wheel allows the lot to turn together, the motor could of course not turn.
I have been a bit to busy to mess around but my next job will be replacing the gears for steel ones, I can put up with the higher level of noise for the durability factor, HPC a company in the UK stock the gears and the bearing, I just need to double check the pitch and get them ordered.
The new Puma has a much better internal gear, the ones pressed in to the inside of the motor housing don't sit that great and manufacturing tolerances in the hub casing seem rather wide at times that I feel the basket gear approach is much better, I have never seen any failures with the basket gear.
Don't be tempted to split the motor further (i.e.) removing the flywheel, this can be a nightmare to re-assemble, I had to use a lathe and a lot of swearing to get it back on and spinning true, id advise only ever removing the free-wheel.
Knoxie
Ok if you keep the motors to the rated power 350 or 500W then you wont have any problems at all, the problem comes when you move towards 1KW or above and of course how you use the motor.
At just 48V 35A it is possible to quickly wear the planetary gears with hard acceleration, this of course inst unacceptable as the motors are not rated for this power use, that said they can be made to take the increase in power.
Another thing that can happen is the free-wheel body slips on the main inner drive gear, this can be fixed simply by dropping 4 blobs of weld on to the rotor and drive gear, I did this on mine only to have the gears wear about a month later.
On my old school Puma (BMC Really) the gears have worn some and are slipping, from a dead stop if you open the throttle you go nowhere, if you go easy its fine and doesn't slip, I haven't had this motor apart nor am I too worried as I just peddle from the start and go gentle on the throttle (none of my other Pumas have done this).
The free-wheel can easily be removed, you need to use a long armed crank puller, like this one
Once off you can flip the thing over, undo all 3 x circlips and remove the Nylon gears, these are pressed in to bearings, it would be easy to find the same gears in metal and get new bearings pressed in to them, this would of course make the drive more noisy but it would never break, whilst you have this removed it would be a good idea to weld the crank at the same time.
For sure the new Puma controller is better on the Pumas and is designed to run with motor, the xlyte can be used but it seems a little hit and miss on certain controllers and at certain voltages, I have never heard of any problems at 48V but 72V can be a problem as we know.
Another thing people don't need to worry about gear failure jamming the motor, if all gears fail and jam, the free-wheel allows the lot to turn together, the motor could of course not turn.
I have been a bit to busy to mess around but my next job will be replacing the gears for steel ones, I can put up with the higher level of noise for the durability factor, HPC a company in the UK stock the gears and the bearing, I just need to double check the pitch and get them ordered.
The new Puma has a much better internal gear, the ones pressed in to the inside of the motor housing don't sit that great and manufacturing tolerances in the hub casing seem rather wide at times that I feel the basket gear approach is much better, I have never seen any failures with the basket gear.
Don't be tempted to split the motor further (i.e.) removing the flywheel, this can be a nightmare to re-assemble, I had to use a lathe and a lot of swearing to get it back on and spinning true, id advise only ever removing the free-wheel.
Knoxie
