Duel wheel e-bike build

[rockypro1]

Hi,

I am going convert my Specialized Mountain bike to an 2wd e-bike. I was going to convert my BSA Tandem to duel e-wheels but it was to heavy and unsafe. So I'll put a middrive on it some time. Any way I got the two e-wheels and started the build. Have a look at my videos to see where I'm at.

Part .9 of my build. https://youtu.be/ceiI3O_NyrU?list=PLUoG2xMUCelqZIePssUpDk4ncQyTpg45g

 

[minde28383]

Looks nice. Lightweight, Battery goes into the triangle? Those controllers are not small.

 

[rockypro1]

Thanks,
The weight is not too bad tbh. I'm going to get a rack type battery for the back. I'm not sure yet maybe move one of the controllers to somewhere else and a bottle battery. I've seen the controllers put under the front of the frame so I have to do a bit of moving around to where suits best.

 

[flat tire]

My opinion is as follows: unless this is a concept project all about regenerative braking with the front, you will lose more than you will gain with a front motor. There are motors that will easy take 6kw, or whatever you want really. Or a mid drive if you're worried about weight distribution (in the case of a 2wd hub motor bike, at the cost of even more unsprung weight and increased moment of inertia.

 

[motomech]

It's unclear to me what you are trying to accomplish. How do you keep 2 direct drive motors from working against each other? How are you going to do the throttle(s)?
It's well known that a 9C motors need some serious Volts to have decent performance, for the money to do what you are trying to do, you could take a single motor, put it on 72 Volts with a serious controller and have better performance at half the weight and a lot less money.
Having been riding a 2WD since 2011, a lot of other questions come to mind, like, with space at such a premium, why use 2 huge genaric controllers? To get a measly 26 Amps, you could use 2 6-FET Infineons, which are the size of a pack of cig.s. Then they could go under the rear rack and place at least some of the batteries in the frame triangle. And you are going to have to have a lot of batteries. I seriously doubt a "bottle battery" will run one of those motor/controller when I think the highest discharge rate one of those can do is 20 Amps.
I could go on and on about what I see as potential problems, but I don't want to seem to negative. But I really think you want to rethink this project.

 

[motomech]

Oh, one more thing I should mention. In the limited text at You Tube, you mention you are waiting "for a torque arm". You do understand, w/ those motors fighting each other, you are going to need 4 torque arms.

 

[Tom L]

Was this what you meant in the title? Seems appropriate but I’m not sure you did it on purpose.

“Dual” means having two parts. “Duel” refers to a conflict between two entities.

 

[motomech]

Very clever

 

[Chalo]

I don't think a direct drive hub motor in a suspension fork is a good idea. For the bike you have, feeding the rear motor more juice is probably better all the way around. Less weight, less cost, better suspension action, less opportunity to slide out the front wheel.

 

[rockypro1]

This is the setup I'll have to power the e-wheels.


This is the power from the throttle to the controllers. I will be putting a switch between the green wire to have either front or rear or both wheels running.

 

[rockypro1]

Or this one same as above.