DIY electric bike

[kieranc]

I want to build myself an electric bike as economically as possible, hub motors are nice but probably a bit expensive... I'm hoping to do this for under £150. I'll be building it onto an existing bike, steel framed so welding on brackets isn't a problem..
my initial thoughts were with the electric scooter motors you can buy on ebay, 200-500w ish, they run at 2500 rpm though. if i were to gear it down 10x, would it be roughly suitable for my needs? are there any other motors which would be more suitable? what happens when i start pedalling when the motor's flat out, is there a chance of running the motor too fast?
I'd probably go with a pair of 12v SLA batteries, maybe initially with a 12/24v switch for the control but more likely a controller from 4qd eventually.
has anyone else done this? seems like it could be fun

 

[Miles]

Hi Kieran,

Have a look here: Technobots Ltd 100W to 450W Motors

Specifically at the MY1018E 1470-036

You'll need a freewheel to isolate the motor and another freewheel to isolate the pedals.

The reduction ratio that you need depends on the speed range over which you want help from the motor and the size of your wheels.

 

[frank9755]

You could build a bike for about that amount of money using SLAs and a motor, controller and other electric parts sourced directly from the manufacturers in China.
You'll find plenty of info on my old posts or those of others. Search on Suzhou Bafang and/or Tongxin.
Good luck!

 

[wgaBloke]

Well the Kit turned up thismorning which was good service indeed.
I had it delivered to my place of work so i could show the chap's and see if i could get more people interested. Not a bad idea as i work for the biggest inland Bus company in NSW. Well there seems alot more interest now they can actually see what and and how the kit actually fits. Management even offered there workshop to fit the bike. I knocked back the offer as i do have all i need at home to complete the job. The Boss then asked if he could have a ride once its completed, and offered me an earlly mark. Well being friday how could i not accept that offer so here i am at home, having a quick cuppa before i go tackle the task.
And to think, it's World Enviroment Day , i couldn't have timed it better.

i will post my expieriences lateron thisevening.

 

[Miles]

wga,

Methinks you've confused this thread with your own:
http://www.pedelecs.co.uk/forum/electric-bicycles/2198-cyclone-diy-kit.html