2,000watt dual motor conversion

[HoopersEbike]

Hello everyone I just joined this forum and thought id show my bike and see if anyone has any ideas for the problem I’m having, my bike is a 80s Ross that I put two 1000 watt motors on being powered by a 52 volt battery in a backpack with quick disconnects it runs great and quickly get up to 36mph, I have another 48vokt battery that I wanted to power the front and have the 52v to the rear, I tied the two throttle cables together to run both motors at the same time, with one battery it worked fine but adding the 2nd battery I believe the power is being shared between them from the throttle harness and over volts it to the point of it goin into a limp mode, I’m working on modifying another twist throttle to be used next to the other one, I was wondering if anyone had any ideas to still use one single twist throttle

 

[Clyde]

Not an electrical engineer, but you'd need to find a way to isolate the two circuits while using the action of the throttle to control both motors. No clue here, but nice bike!

 

[HoopersEbike]

Not an electrical engineer, but you'd need to find a way to isolate the two circuits while using the action of the throttle to control both motors. No clue here, but nice bike!

Thanks! I’ll post what I come up with, it’s going to be two separate twists on the same grip that I’m going to try to use together or attach together somehow

 

[zzRider]

Hello everyone I just joined this forum and thought id show my bike and see if anyone has any ideas for the problem I’m having, my bike is a 80s Ross that I put two 1000 watt motors on being powered by a 52 volt battery in a backpack with quick disconnects it runs great and quickly get up to 36mph, I have another 48vokt battery that I wanted to power the front and have the 52v to the rear, I tied the two throttle cables together to run both motors at the same time, with one battery it worked fine but adding the 2nd battery I believe the power is being shared between them from the throttle harness and over volts it to the point of it goin into a limp mode, I’m working on modifying another twist throttle to be used next to the other one, I was wondering if anyone had any ideas to still use one single twist throttle

How did you "tie the two throttle cables together"? Are you using a single controller for both motors?

Be careful! 36MPH is a lot on a bicycle. Hope you are using hydraulic disc brakes (with BIG discs!).

 

[HoopersEbike]

How did you "tie the two throttle cables together"? Are you using a single controller for both motors?

Be careful! 36MPH is a lot on a bicycle. Hope you are using hydraulic disc brakes (with BIG discs!).

Each motor has its own controller, I attached the other connector from the other kits throttle to one, so pretty much one throttle cable splits and connects to both controllers, right now I have the original pads from 1987 on there haha I’ve learned to be very careful riding but I agree 36 is fast , hoping to go faster though!

 

[GypsyTreker]

So on YouTube Micha @ eBike School does a video that deals with using one controller for front and rear motors. That might help

 

[JES2020]

Hello everyone I just joined this forum and thought id show my bike and see if anyone has any ideas for the problem I’m having, my bike is a 80s Ross that I put two 1000 watt motors on being powered by a 52 volt battery in a backpack with quick disconnects it runs great and quickly get up to 36mph, I have another 48vokt battery that I wanted to power the front and have the 52v to the rear, I tied the two throttle cables together to run both motors at the same time, with one battery it worked fine but adding the 2nd battery I believe the power is being shared between them from the throttle harness and over volts it to the point of it goin into a limp mode, I’m working on modifying another twist throttle to be used next to the other one, I was wondering if anyone had any ideas to still use one single twist throttle

That's way above anything I would know at this point....maybe just strap a small jet engine on ?

 

[rich c]

I thought the controller fed a voltage to the throttle and measured what came back. It's likely not a clean signal to the two controllers. But I'm not electrical engineer. I'm always baffled why people what 2 motors when you can put one big one with a big controller and have less weight and easier control systems. I've seen single motor bikes going 50mph, so speed can't be the primary reason to use 2 motors. Or is it?

 

[HoopersEbike]

I thought the controller fed a voltage to the throttle and measured what came back. It's likely not a clean signal to the two controllers. But I'm not electrical engineer. I'm always baffled why people what 2 motors when you can put one big one with a big controller and have less weight and easier control systems. I've seen single motor bikes going 50mph, so speed can't be the primary reason to use 2 motors. Or is it?

Yea looking at the wiring for the throttle it looks like it gets power for lights showing battery life and going to the twist sensor, I started off with just a rear motor but wanted more power so went to a 52v but wanted more power and thought all wheel drive would be cool so got another motor, now I’m at the point where I want more power again and have another battery so I figured why not try to hook it up , it’s been an experiment figuring everything out being my first ebike, single big motor in the rear is my plan for next year on a better bike , thinking 12,000watts !

 

[Clyde]

Your problem is obvious: not enough wheels!

Try this for your next build.

 

[GypsyTreker]

I think innovation and doing builds or mods outside the box is a draw to forum life. Lots of innovation on this forum, lots of knowledge. Keep it coming boys and girls!

 

[HoopersEbike]

Your problem is obvious: not enough wheels!

Try this for your next build.

View attachment 58863

Man that things got disc brakes all around and some suspension! I’d put two 3,000 watt hubs in the rear and do donuts haha

 

[Clyde]

4

4 3k watt hub motors.

That is all.

 

[HoopersEbike]

So here is my plan so far, I had an identical throttle from the other kit so I trimmed the housing and am going to attach a smooth piece of stainless to it , the idea is when I have next to each other on the same bar I can use both with one hand, at least that’s the plan , not sure if it will be practical or useable or safe really but I’m going to find out, I’m gonnna have the throttle closest to me powering the rear 1000hub at 52v which will do around 30 on its own and the other powering the front 1000hub at 48v to really get moving, I’m going to start shaping the throttle now and hopefully get wiring done this weekend

 

[Clyde]

That seems like an elegant solution, and gives you individual control over either motor in a pinch.

 

[HoopersEbike]

Well got the throttles working by completely separating both kits, I kinda figured it would be uncomfortable to ride and I was right , between having both battery’s on my back and using 2 throttles it took alota fun out of riding it, oh well it was worth a try only took a couple hours of wiring , I’ll be switching back to one 52v battery to power both wheels and leave well enough alone

 

[HoopersEbike]

After ditching a dual battery set up I went back to my single backpack battery , I added battery quick disconnects that can handle plenty of power, they make it very easy to sit down and plug in and with my battery having no off switch the disconnects coming from the battery are still always live but very unlikely to arc out on anything when not plugged in and have dust covers to cover the leads further, new continental tires are next my front tire is bald from spinning when I take off