Powabyke retrofit?

[averhamdave]

My old Powabyke Euro - about 8 years old (not sure, secondhand when I bought it about 5 years ago) is still a good strong bike. The 36v of SLA batteries are very good.

Of late it has developed a steady "misfire", ie an apparent intermittent in power supply. It has the hallmark of a loose connection but I can't find one although I have yet to split the battery case and check the connections within. I'm wondering if the brushes are shot?

Anyway my question is - has anyone ditched the heavy, limited speed brushed front wheel and motor and fitted a modern hub motor, ie GoldenMotor or similar? I know I would have to replace the associated electrics etc, but has anyone done it? I was hoping to fit a 500 or 750w, 36v hub. I wish to do a steady 20+ mph on the flat (off road).

Anyone a view on how the units would compare, ie old Powabyke hub against new proposed hub?

Thanks

 

[monster]

actually i think brushed motors are pretty good. they have a lot going for them. if you sell it, let me know.

 

[monster]

if you want to go faster double the voltage of your batteries this will double your power (you may have to buy another crontroler from ebay, £20). if you find the motor starts to over-heat, which is quite likely, then take the side plates off and drill holes in the side covers. this aproach will easilly get you to 20mph with minimum cost and you can still keep your (ahem, cough, cough ) "200w" motor .

 

[flecc]

You could be very disappointed with another motor, the Powabyke one being one of the most powerful on the market. Faced with your bike's weight, most other motor types would be worse performers and the direct drive Goldenmotor in it would be a complete wimp on hills unless fed with loads of volts. Their reliability record is poor too, unlike the Powabyke motor which is very reliable.
.

 

[averhamdave]

Oh, OK thanks for the help so far.

Carrying 3 SLA batteries on a heavy bike is already a strain. Could I just add a 4th in series, say mounted on the carrier and experience some increase in power without resorting to another controller?

Is it practical - either physically or economically to pack the existing battery carrier with A123 cells to give say 48v or more, and at the same time save weight? Anyone done anything like this?

How would I remove the "governer" mechanism from my bike? It seems to cut the power supply off at about 15mph, certainly well below 18mph. If I can't solve that prob, I'll probably not stick with the Powabyke motor, otherwise I'm happy to.

Thanks, Dave

 

[monster]

there is no "govenor" or nottle neck holding back your ebike. all its components are rated for around the same power output ~200W. although the motor might have potential for much more power, maybe double.

you should buy a watts-up meter for your bike now, so that you can quantify what kind of power you have/want, other wise its just a guessing game. you can check if the controller is limiting your power buy wiring the battery straight to the motor via a handle bar switch and comparing theis power to that when using the controller normally (it will probably be the same tho). if ther is a difference then great! -just buy a £20 controller on ebay and you will increase your power by whatever the difference was. with the watts-up meter see how much power you are putting through the hub motor. see if you notice the voltage saging a lot when you accelerate. if you notice the voltage sag down lots then there is lots of potential for power increase by buying more powerfull batteries. doubling the voltage of the batteries will roughly double the power, if the rated current output is the same. so you can increase the power in two ways, by increaseing either or both of voltage and rated current output. say the voltage sags by 20% when accelerating hard. this means if you buy a high power 48V battery you could increase the power to 320w. a high power 60V battery would increase power to 400W. if you find the motor gets hot then giving it more ventilation will increase its power some more by reducing resistance in the windings and allowing more current to flow.

200w x48/36 = 267W (from voltage increase)
267 x 1.2 = 320W (from current increase)

you should dump those bricks and get some real batteries. no-one uses SLA on bikes anymore! get some ping from pingbattery.com. his batteries include charger and BMS so they are easy for the novice ebiker.

if you still want more power after all this, then you will have too buy another motor.

 

[averhamdave]

Thanks Monster for your help so far. I'll be trying these ideas in he coming weeks.

For now though, given that you have explained that there is no "governor" fitted, why does the power cut out at 15mph?

Accelerates steadily up to 15mph with a mix of power and pedalling then at about 15mph, the motor cuts out and then cuts back in when speed drops. Can I bypass this function to keep the motor working?

Thanks again

 

[flecc]

I don't think there is any governing on any Powabyke Dave, as far as I know the motor runs to maximum revs on the supply voltage and doesn't cut out as such, just that the freewheel allows the bike to run beyond that speed without the motor assisting. As the speed drops, the freewheel re-engages the drive. Powabykes certainly aren't speed machines, their strength is more in hill climbing power.

Most hub motor e-bikes are similar, only a very few have any restriction allowing slightly higher speeds like 18 or 20 mph once derestricted. Amongst best known brands, only Wisper on the 905se model and eZee at times on a couple of models have a derestrict facility.
.

 

[mygrumpy]

Powerbyke

Hi.Averhamdave.Have Powertryke. 200 motor. changed the controler for a 4qd controller.still does 13 mph flatout.it might the weight i carry.9 battries plus 13 stone.Try a bigger motor.John(Mygrumpy)