Converting an electric bike

[winchman]

I have two of these

One is getting a 212cc 7HP engine conversion in place of the 97cc engine, its almost finished.
So we are wondering do we make the other one bigger and faster??? Or do we make it electric as then we can potter around on it more easily than a petrol one?
Any thoughts on how to do it? Cheaply of course?

 

[GRW]

I have two of these
View attachment 447868

One is getting a 212cc 7HP engine conversion in place of the 97cc engine, its almost finished.
So we are wondering do we make the other one bigger and faster??? Or do we make it electric as then we can potter around on it more easily than a petrol one?
Any thoughts on how to do it? Cheaply of course?

A mate converted a hardball mountain bike to electric. He bought a generic Chinese motor kit (you can get them with a hand throttle so no need to pedal to initiate the motor)...... and his genius move (as the voltage is 36vdc) was to use 2 of 5A 18v nominal Makita Power Tool batteries for the source power.

It works incredibly well. With pedal assistance even on tough, big climb off-road rides he gets around 15km range off the 2 tool batteries (he can easily carry 2 spares in a backpack to double the range.

OK, no pedal assistance on your pit bike, but if you wanted Range you've a lot more space (vacated by the petrol motor & the fuel tank) to fit bigger battery storage.

 

[lazybones51]

My son has a little 250w 24v electric bike, uses one of these motors https://www.ebay.co.uk/itm/174202821244
You can get 500w, and maybe bigger versions of the motor and controller. That should do the job.
Identical to this

 

[winchman]

Thanks
Initial thoughts are use two Milwaukee batteries as we have them, but don't want to cook them?

 

[Greeves246]

Do what Clive Sinclair, sorry Sir, did and fit a washing machine motor and a car battery. Call it the C6.

 

[hotponyshoes]

Thanks
Initial thoughts are use two Milwaukee batteries as we have them, but don't want to cook them?

This has always been my worry with using (expensive) tool batteries for anything other than the original application.
I know they usually have protection against over-discharge etc but I am not sure if thus is in the battries or the tools.

I suppose you could use the controller from an old broken drill or something. You would also get the battery mounting then as well.

Possible you could even use a drill/grinder/saw/whatever to provide the motor etc so everything is designed to work together?

Or just buy some cheaper (lidl etc) batteries and chargers. Could refule the bike at the same time as doing the shop...

 

[lazybones51]

The bike I shared above just uses two 12v lead acid batteries wired in series, cheap and have lasted a good few years without any issues.

 

[GRW]

The bike I shared above just uses two 12v lead acid batteries wired in series, cheap and have lasted a good few years without any issues.

I have exactly the same (in parallel) for my "leisure" batteries in my camper build. Lots insist that you need "proper" deep-cycle (more expensive) batteries for the job - but my last van with a single 019 battery did over 8-years without failing (I think I still have it now, still holding charge etc).

The trick is not to over-discharge - stick to 50% DoD & no more (which equally applies to deep-cycle LA batts anyway if you want them to last).

 

[frank horton]

I just bought some gell motor cycle batteries for my E bike...still worked after 4 years of fairly heavy use.....
wish I had it now.....
Now have a SURON bigger bike/m/bike....bloody hopeless.....should have bought a Honda 50.....

 

[CompoSimmonite]

If you state the batteries are for a mobility scooter then they are vat free

 

[Erie Fred]

I think an older fan cooled 440 sled motor with torque converter would be just the ticket......YeeHah !

 

[winchman]

I think an older fan cooled 440 sled motor with torque converter would be just the ticket......YeeHah !

It would have a Sachs rotary sled motor if we could find one in the uk.

 

[Erie Fred]

It would have a Sachs rotary sled motor if we could find one in the uk.

More Power !
How about a tripple ?

 

[angellonewolf]

I have two of these
View attachment 447868

One is getting a 212cc 7HP engine conversion in place of the 97cc engine, its almost finished.
So we are wondering do we make the other one bigger and faster??? Or do we make it electric as then we can potter around on it more easily than a petrol one?
Any thoughts on how to do it? Cheaply of course?

twin electric motors ?

 

[Erie Fred]

twin electric motors ?

Light hydrocarbons are best here.
"Greta be damned".......