Duel motor... Would ya?

[Low]

hiya, just finished my big battery build came out better than my predicted 15ah, nearer 18, its a 13s 11p laptop salvage job, charged and all good, i built the battery initially so as to get more range, the 11Ah bottle battery thing sucks on range with the 1000wat motor, D8v has been of massive help throughout, im going to simple Y conectors pre controller, anyways i then saw the below picture and dangerously got to thinking...

Wouldn't it be nice to have a front wheel motor on my cyclotrocity stealth as well, could get the kit, use my newly built battery to power it, could use the back motor until the bottle battery died then just swap onto using the front motor, coukd have a nice thumb throttle on each side of the handle bars and if i did need some extra boost could just hit both motors at the same time.

Im interested in knowing if life really is that simple or if im drasically over looking anything?

Also... Do you think a bike as iv described wouod go past its usual 30mph with both motors going?

 

[D8ve]

It will stand out. Seriously illegal, 1,000 watts in the front is not a good idea anyway, your range will also drop further.
The speed is limited by how fast the motor will run as well so at 36 volts it could be near limit bumping to 48 might get you to nearer 40 mph.
You are also getting into seriously dangerous speed on a bike with limited brakes etc.
As a member of the fun police it's a bad idea for general use.

 

[Deleted member 4366]

It's very simple to make a 2WD bike; however, it's better with two smaller motors because of the weight. Most forks can manage a normal 250w geared hub-motor, but for any more power than that, you need steel forks.

You need a battery capable of giving enough current for both controllers at maximum. Then you need two controllers and two motors. You can run both from one throttle, one pedal sensor and one set of brake switches as long as you only connect the signal wires to the second controller (no 5v wire). Ground is common, so optional on the second controller.

I've made several electric bikes with two motors. Four had two hub-motors. One had a CD plus a front hub-motor. One had three motors - front, middle and rear. Of the four double hub-motor ones. I've had one with two low-speed motors, one with two medium-speed, one with two high-speed and one with one high and one low-speed. The one with one high and one low was best for all-round riding. All of them would blitz any Bosch/Yamaha/Brose bike in a climbing contest, except maybe the one with two high-speed Q100s because it was happier at 25 mph.

 

[Low]

All valid... The actal bike it self is full of cheap componants, my old specialised hardtail has spoilt be with hydrailic brakes etc

Certainly wouldnt be doing it for flat out use, just like thd thought of having two completly seperate systems esp from a reliability perspective, should one breakdown on the way to work would be nice to just switch over and continue on a backup

Also 40 mph on this bike would be lethal, some times tho on a safe stretch would be nice to just tricke up over 30 but that would be rare

Il stick with what iv got and double the batteries up on the rear hub motor.

Thanks all