Converting petrol pit/scramble bike to electric using same principle of e-bike

[Jimmy1234567]

Hello ,
I am wanting to convert the pit bike shown or similar to electric so that my 10 -11 year old son son can ride it without disturbing the neighbourhood. There are kids motorbikes out there for sale ready made but they are all too small for him.
The pit bike is not very large and weighs about 120 lbs without the petrol engine and my son is not heavy, about 30-35 kg and I have a few questions about the conversion that I hope will correspond to the workings of an e-bike.

1.) What sized motor wattage and voltage would be an ideal size to give it a good but safe turn of speed and make it perform well over cross country.I am thinking 36v 800w?

2.) Can I use a twist throttle and speed controller etc kit (i.e 36v 800w) suitable for an electric bicycle.

3.) If I keep the rear wheel exactly as it is would an ideal sprocket on the motor be 14 tooth or should it be less or more?
Any advice appreciated
Thanks

 

[Deleted member 4366]

Go to Endless-sphere,com, join there and ask on their forum. They have a special section for electric motorcycles.

 

[Jimmy1234567]

Go to Endless-sphere,com, join there and ask on their forum. They have a special section for electric motorcycles.

Thanks for your reply and advice. I have posted this question on this site and two electric motorbike forums but had no advice yet. I thought it would be quite a basic scenario/project.
Cheers James

 

[Deleted member 4366]

Post it on Endless-sphere!

 

[anotherkiwi]

What d8veh is trying to say is: "we don't do motorbikes here, only pedelecs"

OK we stray into the odd s-pedelec or other high speed thang, but never ever motorbikes.

 

[rich_r]

As above, this site is focused on pedelecs (or electrically assisted pedal cycle, EAPC) - ie bicycles that gain electrical assistance only when the pedals are being turned. It exists as the pure electrical powered vehicle community already has sites such as Endless Sphere.

I suspect you could theoretically use a motor intended for a pedelec, but there are likely to be better suited motors and controllers out there.
Most modern pedelec motors either drive the pedal crank through meshed gears, or use a motor in the centre of the front or rear wheel. Hub motors will probably be physically too large for your pit bike wheels though, and as they're designed for wheels of around 26" in diameter, likely to have poor torque and speed characteristics anyway. You might be able to adapt a crank drive one by welding on a sprocket, but again you may have the issue of the speed/torque not being optimal.

I wish you luck though, it sounds like a fun project.

 

[craiggor]

There is plenty of motorbikes/mopeds on here they're just not registered .

Sent from my D101 using Tapatalk

 

[Deleted member 4366]

I'm not trying to say anything about this site. They convert bikes like that on Endless-Sphere every day, so that's the place to go for info.

It really annoys me when you tell people the answer to their problem, but they always know better than to try your suggestion.

It would have taken less time to check out what I suggested than to come back here and moan about my suggestion!