Powabyke - mechanical



Weight

The powabyke is quite heavy, due mainly to the three 12v 12a/h lead acid batteries that make up the battery pack. These weigh a total of 12.5 Kg.

Brakes

Although the powabyke that I have was not new when purchased, I'm pretty sure that nothing had worn enough to need replacing. The brakes (caliper type, front and back) seemed remarkably ineffective at anything other than low speed. No amount of adjustment seem to improve this, and this has always been a concern. When, after for years, that needed replacement, I went to 'electric byke sales' in Hope street yard, Cambridge (see link below), and they ordered a set of better-than-usual pads. They cost about twice the price of the standard item, but are much better, and I no longer feel compromised.

Tyres

Puntures seem more frequent with this bike than with the usual touring bike (despite the chunky looking tread of the factory fitted tyre). With the bike being so heavy, inner tube replacement is not very pleasant. There are at least two useful things that can be done. Firstly, you can consider kevlar tyres. Or you can partially fill the inner tube with 'Dr Sludge'. This is a non-setting rubber solution that rolls around the tube, sealing any puncture that may occur.

Gearing

From my touring/racing days, I recall that cyclists are either 'tweakers' or 'pushers'. This 5 speed bike suits the tweaker - but I am a pusher!, so always have the bike in top gear, and have never used the remaining four gears. At some point, a larger pedal ring will/ought to be fitted.

Motor/gearbox

The motor is rated at 250W, according to the Powabyke blurb, but on my bike the unit does not have a manufactures name on it, so I have no more data than this. It always runs cool, no matter how harshly it is treated. It is possible to strip the unit down, and this reveals a motor on one side of a central plate, with the gear box on the other. The spindle on the motor side is drilled out to enable the connecting wires to exit. There is no sleeving fitted to the drill-out, and a friend has the unpleasant experience of these shorting out when the spindle turned in the folks because it had been delivered not tightened up enough. A short here will blow will blow-up the control transistor in the controller.

Following the gearbox, there is a ratchet drive to the wheel, so it is impossible for the wheel to be powered backwards (unless you will fit the wheel in the forks the opposite way, I suppose...).

After four years use, the gearbox was becomming quite noisy, so it was decided to see if access was possible. It is:


motor

With the wheel removed from the bike, both the outer six pozi drive screws and the inner six need removing. On my bike, non of these difficult to turn.

The outer face (shown in picture) then has to be prised away from the main body. Again, this was easy enough on my particular bike.

Remove the four (I think) screws securing the gearbox lid and lift away.





Interestingly, although the gear box is completely filled with lubricant, this is very waxy and quite solid (at the usual UK temperatures, at least). With being solid, I found that the lubicant was simply no longer in contact with the gearing. I suppose all that was required was to use a heat-gun to melt the lubricant back into the gears, but I actually added grease around the gear teeth instead. Replacement should be incident free, and the result is certainly a much quieter machine.


Where to have the motor/gearbox serviced in Cambridge

As far as I am aware, there is only one bike shop that will do major repairs on electric bikes, and that is:

http://www.electricbikesales.co.uk/

They are just off Mill Road, at:


Hope Street Yard
Hope Street
Cambridge CB1 3NA

01223 247410


Battery housing

Two sets of replacement batteries have now had to be installed. In doing this, you soon realise how flimsy the battery housing is. It doesn't help that a very brittle plastic is used, so be very careful if you decide to do this. The screw bosses are particularly poorly designed, and will break away very easily.