# Auto Hub Motors? for Motorcycle



## storx (Nov 24, 2013)

I am in the process of building a Motorcycle similar to the Scorpion P6 design, but after test driving another builders motorcycle setup using an Harley engine in the rear to drive the bike, i found that under 35mph you cant use more than 30% throttle or its just a spin fest and even when you have traction if you hit a small dip or bump in the road, the rear jumps due to low weight and causes it to become a scary situation... 

My question is does anyone have any better ideas to powering the front wheels with electric motors? I got the idea from some friends and ive come up dry trying to figure it out except for these 13 inch kelly units.. but they are limited to 77mph....









Example of what i am aim for and what i am building...


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## Woodsmith (Jun 5, 2008)

My first thought was to use a Citroen 2CV transmission and a single motor but that would impact on your leg room unless you made the chassis longer.

I have one and would be tempted to use it in this format at some point.
Gotta finish the current project first though.


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## esoneson (Sep 1, 2008)

Storx

A couple of these up front might meet your needs.

http://www.enertrac.net/

Two doubles (4 motors) might be a little too much. But you sound like you want some fun.

Eric


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## storx (Nov 24, 2013)

esoneson said:


> Storx
> 
> A couple of these up front might meet your needs.
> 
> ...


I seen those, but they are limited to 60mph... even worse than the Kelly units.. i asked Kelly about using their hub design motor on a larger maybe 18 inch wheel and they responded back that it wasn't powerful enough.. little confused.


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## Duncan (Dec 8, 2008)

I know it's not the answer you want but you should hunt down the miscreant who stole your other rear wheel,
Then you can have a decent front/rear weight balance

I have 55% of my weight on the rear (driven) wheels


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## storx (Nov 24, 2013)

The reason i am wanting to keep to 3 wheels is due to being able to tag it under Motorcycle and not a assembled from parts car.. both of the recent custom cars built over on Locostusa.com in the state of florida couldnt get it registered under anything other than Assembled from parts kit car, so no insurance company will touch them outside of kit car companies and both had quotes WAY up there in cost....


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## Duncan (Dec 8, 2008)

Hi storx

If you can't find the other wheel you need to look carefully at weight distribution,

With an IC engine you probably don't have much weight at all on the rear wheel,
With electric I would be trying to get some more weight there.

It's a trade-off too much rear weight will probably affect the handling,

A 1/3 -on each tire would be my starting point - and I would try a bit more on the rear and see what happens

Start with 40% rear - 60% front - then increase the rear weight until it starts washing out on corners

With an electric you can probably do that by mounting some batteries low down behind your bodywork
When it works you can extend the bodywork - the rear wheel doesn't steer so you can use the space either side


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## Karter2 (Nov 17, 2011)

did you read Rippertons exploits with Hub motors ?
http://www.diyelectriccar.com/forums/showthread.php/mira-inboard-hub-motors-82349.html
I would avoid them like the plague and do something similar to his final solution..single motor/controller and compact transaxle unit if you still want FWD.
but really you should work on weight distribution, and wheel/tyre choice, ( wide & sticky) for a simpler single RWD set up.


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## storx (Nov 24, 2013)

Thank you for the posting of that destruction...

Another idea i thought i would ask among yall...

The EV motors that have DOUBLE shafts are these shafts a single unit?? i ask because i have no experience with these and thought of something last night that MAY work... 

IF, these shafts are not a solid single unit... then i could mount a SINGLE electric motor in the very front of the frame where the radiator for the Bike engine was originally destined and use a sprocket and chain combo to achieve the speed range i am wanting.. 










OR...

Use a pair of smaller thinner motors mounted in the front and power each wheel separately... 

OR....

Idea my friend mentioned...

use 3 even smaller units that have a combination power output desirable and use 2 in the front and 1 on the rear wheel to have distributed power and better traction, as i expect FWD driven wheels will still want to spin occasionally with the instant torque.. 

I have 24 inches roughly between the rails of the frame in the front... and this would give the motors optimal airflow for cooling up there also..


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## Duncan (Dec 8, 2008)

Hi Storx

How much performance do you need?
With appropriate weight balance you can get stonking performance just driving the rear wheel
(See Morgan three wheeler)

You should get it running with a simple set-up (but more weight on the rear) 
Then worry about extra motors and front wheel drive
Remember weight is NOT your friend - keeping the whole thing light and simple is the best way


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## storx (Nov 24, 2013)

Duncan said:


> Hi Storx
> 
> How much performance do you need?
> With appropriate weight balance you can get stonking performance just driving the rear wheel
> ...


I was actually thinking of ditching the motorcycle engine rear powerplant and go with EV FWD, i just dont want something that i cant drive around an AutoX track and push the limits without it just spinning on me or going squirrelly..


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## Duncan (Dec 8, 2008)

Hi storx
_i just dont want something that i cant drive around an AutoX track and push the limits without it just spinning on me or going squirrelly.. 
_
Rear wheel drive is much more fun on the track - and things like the Morgan are not slow!

Front wheel drive can be fun as well but with a trike - RWD is so easy - whereas FWD is going to be a bit more tricky


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