# Electric motorcycle compared to ICE motorcycle.



## major (Apr 4, 2008)

hh3130 said:


> So I'm very interested in building an electric motorcycle. But I'm concerned that the performance will be less than what I'm used to on my ICE powered motorcycles and after spending in the neighbourhood of $6000+ to convert one that would be very disappointing.
> I was considering an ac-20 650amp @ 120V with CALB cells which should provide around 80 ft/lbs of torque from 0-5000rpm which should be awesome torque. My biggest concern is the lack of a transmission in most conversions, which would have less mechanical advantage than compared to my vmax with above 60 ftlbs of torque at the rear wheel between 3000-7500rpm. But has the advantage of gears for mechanical advantage.
> 
> So my question is, are their anyone in the forum that have had high performance ICE powered motorcycles and have converted a motorcycle to electric and how did they find the performance?
> ...


Here's a comparison:









This graph was lifted from the elmoto.net forum, a guy called Noah. As you can see the AC20 compares favorably to this particular engine/transmission. The D&D is a series wound motor and suffers from a wimpy controller. There are a lot of discussions (arguments) about the value of multi ratio gearboxes in eMCs. I don't think they are particularly useful. The 2 US production eMCs have taken different approaches; see Brammo and Zero.


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## Arlo (Dec 27, 2009)

I have a prototype BLDC motor and I have not hooked up the cooling and not been able to push it to the limits even with out the liquid cooling.

You will find more trouble making sure you have good batteries then the motor/controller combo but if I was you I would maybe consider the bigger AC motors?

BLDC is hard to do and only few controllers work with fet motors but the power density is generally better but you loose a little in cruising efficiency.
This video is after I Dyno'd 9.4hp at the wheel since with the same controller I managed to get 15hp and 90ft/lbs with that version of my DIY controller. More to come


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## hh3130 (Feb 14, 2012)

Thanks for the information guys. Still not sure what motor to use, but I think I might go with a 9 inch DC motor. That way if it does perform the way I want I can put it in a car instead. Pretty heavy motor, but if its in a large motorcycle frame and mounted low it should be very smooth power. 

Sorry I didn't respond sooner, works been a little busy.

Take Care.


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## toddshotrods (Feb 10, 2009)

I can give you some initial observations now, and weigh in later with more data. I have two bikes going now, on DC (so far), neither up to full speed yet.

With a tiny (240Wh) 48v AGM pack, and my tiny (4.5 x 7.5") brushed-PM, test motor, and 4.7:1 gearing, Scrape had decent acceleration, but severely crippled "top" speed because of voltage sag, and lack of capacity (to keep going and let speed build). It still gave the impression that it had a lot of potential, and the key was low weight.

With a 6.6 x 9.5", series-DC, motor and that same pack, it now is beginning to feel like a performance bike. I haven't really even cracked the throttle because at this point, I can do harm to the pack. I only have a 48v/300amp Alltrax controller (to be replaced with an Open Revolt), right now but that little pack can only deliver 60 amps, and at that point is is sagging really badly. So with the series motor, I have just barely cracked the throttle, but the bike is accelerating too fast inside the shop already. I have a better (AGM) pack in the works, and will be able to explore its potential soon.

Meanwhile, I put that little test motor in the other bike (Squat), and with just a single 12v/5ah/60amp AGM battery, a starter button 
"on/off _controller_", and steeper 5.8:1 gearing, people here can't believe how fast it is in the aisles of the shop. That bike is getting a tiny, 24v, Curtis controller this week, and the AGMs from Scrape. It is a blast to ride.

My point is, I think weight is the key. With the 9" motor, you are picking up ~100lbs over what I have in Scrape now, just in the motor. Then, depending on what you do with batteries, the weight can get exponentially out of control, and the temptation is to keeping adding more weight (bigger motor, more batteries, etc) to solve the problem. That is the approach cars are forced to take, but I think EV motorcycles present the opportunity to explore the real advantages of electric propulsion, when weight is minimized. With less weight, a smaller motor can provide incredible performance, and result in a bike that is much more enjoyable to be on (better handling, etc, due to lighter weight).


The two hurdles are how much range you need and how much you are prepared to spend, because keeping the battery weight reasonable is the challenge. My bikes are a blast because they're so light but, obviously, I have next to nothing for range at this point. I'm doing it this way to explore my assumptions on building better EVs, and will try to progress slowly into more functional bikes, without loosing the benefits I am enjoying so much now.


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