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[lojan]

Hi there guys glad to be a part of this forum
 
I want to start by saying I'am not very experienced with electronics. I'am designing a bike a project at university, but i keep hitting dead ends and my head feels like its going to explode. I'am designing a powertrain for a commuter bike which should travel around the city fairly easily so it doesnt need to be racey but have good mileage and durable. and also need to design a stabilisation feature( I have decided control moment gyroscopes but thats neither here nor there) I have done alot of research into batteries and have gone with lithium ion or lithium maganese and have made a table showing specs for each type. However I'am getting very confused when it comes to choosing a motor I have been looking up equations and it doesnt seem to make sense to me. I'am trying to work out the horsepower that my motor can provide for me at different speeds. The bike including myself will weigh around 300kg just to mention the bike will have a enclosed shell around the chassis, the general specifications when looking at a motor is quite confusing, I have an example here f a motor I would like to use, http://www.electricmotorsport.com/ev-parts/motors/brushless-motors/motenergy-me0201013601-sealed-pmac-motor-12-96-vdc-13-kw-pk.html, im not sure how I would work out horsepower at different speeds from these specs
also I was told that the motor would only have to pair with the battery in terms of voltage is this true?
Dont want to be a nuisance just hoped somebody could give me some constructive info. Any help is appreciated

[firepower]

Think you may need to decide your max speed and weight and what gear ratio you are using and compare what your max RPM and torque of your motor.
you also need to think about motor controller

Range is basically just increasing battery size to available space in your frame.

here is an archive of 2012 Zero power train brochure, it may be useful for spec to do some calculations.

http://web.archive.org/web/20130513040519/http://www.zeromotorcycles.com/powertrains/powertrains-sales-sheets.pdf

and current motorcycle sales brochure to compare how much spec have improved.

http://media.zeromotorcycles.com/press-2015/press-kits/2015-zero-press-kit-us-e.pdf

MOTOR
Max torque 106 ft-lb (144 Nm) 106 ft-lb (144 Nm)
Max power 67 hp (50 kW) @ 4,000 rpm 67 hp (50 kW) @ 4,000 rpm
Top speed (max) 102 mph (164 km/h) 102 mph (164 km/h)
Top speed (sustained) 85 mph (137 km/h) 85 mph (137 km/h)
Type Z-Force® 75-7 passively air-cooled, high efficiency, radial flux, permanent high-temp magnet, brushless motor
Controller High efficiency, 660 amp, 3-phase brushless controller with regenerative deceleration
Final drive 132T / 30T, Poly Chain® GT® Carbon™ belt 132T / 30T, Poly Chain® GT® Carbon™ belt

[lojan]

Thanks for the reply, I was just wonder what you mean by gear ratio, i was under the impression that if i connected a belt drive to the motor I choose that i can directly feed that power to my wheels? and that the motor controller would control the amount of power transmitted.

[firepower]

Gear ratio is size of motor front pulley to size of rear wheel pulley
example zero uses front 30T to rear 132T = Gear Ratio of 4.4

this will reduce motor max RPM by 4.4 but increase Torque by 4.4

Usually you need to slow motors down and increase torque to be useful.

I think this is correct, I sure other will correct me if i am wrong
google and forums should be able to help you.

[lojan]

Thank you so much for the info, does that mean if i keep the gear ratio as small as possible i can retain the max rpm? would it be easier to incorporate a hub motor instead?? also dont know if you could enlighten me on some of the equations i would need to work out total mileage ? and horsepower at different velocities. I have been trying to equate it with no luck.

[Conanichi]

The Web is great for easy posting good.

[firepower]

Konichiwa, Welcome to the forums Conanichi. this forum is great for info about Zero and Electric motorcycles.
here are some links you might like.

http://brammoforum.com/

http://elmoto.net/

http://evmc2.wordpress.com/