# Hybrid motorcycle - has it been tried?



## kasi124 (Jun 30, 2008)

Just wondering if anybody has tried building a hybrid motorcycle - I am thinking of putting a hub motor on the rear wheel that would power the bike, say up to 15mph, when you reach speeds over that the ICE would fire up. 
Has such a project been attempted?


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## Little Rhody (Jun 17, 2008)

I have seen some bikes with an Etek motor mounted on the swing arm. But I believe the engine bay was filled with batts and controler etc. 

I don't know if I have seen a true hybrid yet. 

LR


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## Phyber Optik (Jun 4, 2008)

*Here's a production Hybrid scooter I ran across:*
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200354817_200354817


_The energy-efficient Expresso PI plug-in scooter utilizes state-of-the-art hybrid technology to save fuel and reduce emissions. In Auto Drive mode, the Expresso uses an electric motor at low speeds. After reaching 20 MPH, its gasoline engine starts up and propels scooter up to 45 MPH. Rider can also choose All Electric for maximum economy, or All Gas for quick acceleration and higher speeds._

*Speed (MPH)*20-45*Watts*500*Volts*36*Miles per Charge*25 










Powered by 500 Watt 36V electric motor at low speeds
49.9cc gasoline 4-stroke engine starts up after reaching 20 MPH
 Scooter has 3 modes: All Electric, All Gas and Auto Drive
Electric motor goes up to 25 miles on one battery charge
Electric motor can handle a 6° incline
Gas engine gets up to 80 MPG
$2500 dolla.


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## hattichya (Oct 27, 2011)

Trying of doin it on my 100cc bike. It is already fuel efficient but still I am keen to built one. Anybody with idea about the calculations?!






Phyber Optik said:


> *Here's a production Hybrid scooter I ran across:*
> http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200354817_200354817
> 
> 
> ...


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## SamM (Oct 27, 2008)

For quite a longtime, I have been thinking about building a diesel/electric drive motorcycle. I suppose that it would be a series hybrid much like a modern diesel/electric railway locamotive. The diesel engine (456cc) would drive a generator that would power an electric motor that would then drive the rear wheel. My search has led me to Generac Generators. An 8000 or 10,000 kW generator unit should do the trick. A VFD (Variable Frequency Drive) may be the best way to power the electric motor. I'm still looking into this and may actually start to put a bike together in order to accomplish my goals. I have already purchased the diesel engine and have it in my storage unit. The motorcycle would be based on a newer model Kawasaki KLR650. It will be stripped down and lightened in order to make the most of the electric motors power. My goal would be a 70 to 80mph topspeed. 

SamM


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## hattichya (Oct 27, 2011)

You dont face any vehicle registration problem at your place. The chassis no. & engine are registered I guess!!!!
Apart from that, Is it possible for a petrol engine??!!. There might be weight issue i fear!!

HatIchYYA


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## frodus (Apr 12, 2008)

There was a guy a while back that stuffed a motor and single cylinder into a cb-style frame, but I can't find it. Had about 1kwh on board. I think it was a parallel hybrid. Looking for it.

Here's one based on a zero:
http://news.byu.edu/archive11-may-hybridmotorcycle.aspx


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## gor (Nov 25, 2009)

there been a lot of discussions on the topic, like:
http://www.diyelectriccar.com/forums/showthread.php?p=253726#post253726
http://www.diyelectriccar.com/forums/showthread.php?p=261015#post261015
easiest - hubmotor and fill room on the mid of scooter with batts 4 long range and highway speeds 
occ choppers hybr bike: 









: ))) found some cool pict on my comp (no idea what it is):


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## Salty9 (Jul 13, 2009)

Gor,

Your pictures could have come from page 2 of http://www.rcgroups.com/forums/showthread.php?t=905411&highlight=alternator&page=2.

I found a few useful bits thinly scattered in a large stew of acrimony.


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## anand.ssukhi (Jul 23, 2009)

I have been planning a similar build , my idea is to use an alternator(~1.5 KW) as a motor /alternator, just for 10-15 secs pulses for accelration during gear changes.
probably i willbe using a 125~150 cc, 130 kg bike
would this work??


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## anand.ssukhi (Jul 23, 2009)

also Iam planning of using .5kwh Lion battries (48v, 12amps), my main purpose here is to increase the mielage, so would this work??


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## Rational (Nov 26, 2011)

anand.ssukhi said:


> use an alternator(~1.5 KW) as a motor /alternator
> 130 kg bike


Neglecting air drag, 
1500 W = ~ 2 hp can lift 130 kg + 70 kg [operator] = 200 kg = 440# 1' in 0.4 seconds.

A 6 degree incline = rise:run = 0.1
so on this hill you could go about 10' in 0.4 seconds, so 17 mph.

You can measure your own hp output in the same way, by running upstairs.
Depending on your age you can put out 1 hp for at least 20 seconds whereas a world class cyclist can do 400W for 20 minutes or so.


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## anand.ssukhi (Jul 23, 2009)

Rational said:


> Neglecting air drag,
> 1500 W = ~ 2 hp can lift 130 kg + 70 kg [operator] = 200 kg = 440# 1' in 0.4 seconds.
> 
> A 6 degree incline = rise:run = 0.1
> ...


thanx Rational, 
By 17 MPH u mean that a 1.5 KW motor can take 200 KG load upto 17MPH ??
and if so what acceleration should one expect, 
and please elaborate " = 440# 1' in 0.4 seconds.",

Regards Anand.


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## Rational (Nov 26, 2011)

anand.ssukhi said:


> thanx Rational,
> By 17 MPH u mean that a 1.5 KW motor can take 200 KG load upto 17MPH ??
> and if so what acceleration should one expect,
> and please elaborate " = 440# 1' in 0.4 seconds.",
> ...


No acceleration or decel; you hit the ramp going 17 mph and it maintains this speed up the ramp. The hp is used to lift the vehicle's weight rather than to accelerate the vehicle.

1 hp can lift 550 lbs 1' in 1 sec. Solving the generic formula for seconds, sec = ft-lbs/(hp-550) so it's (1' x 440 lbs)/(2 x 550) = 0.4 second.
With a slope like this you go about 10' horizontally in 0.4 second so it's 17 mph.

On level ground with 2 hp and 440 lbs you can expect an acceleration of TBD, meaning I have to work this one out. 
I need the drive wheel radius, at least, and the formula relating torque to hp and rpm, T = 5252hp/rpm.


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## anand.ssukhi (Jul 23, 2009)

thanx, again
Seems I'll need to brushup up some primary physics.


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## anand.ssukhi (Jul 23, 2009)

anoopkumawat said:


> There are no hybrid motorcycles, but there are electric motorcycles. As such, they don't have "gas mileage". I saw a "Zero" electric motorcycle on the sales floor at a local dealer recently.


can u please share the details of where in india u found this stuff


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## Rational (Nov 26, 2011)

anand.ssukhi said:


> thanx, again
> Seems I'll need to brushup up some primary physics.


I took a close look at the speed vs. time [t] curve for an electric bike and it shows that the acceleration [a] starts out at about 1 ft per second squared and decreases as the bike top speed is reached.

An easy but approximate way to handle this type of problem is to use Excel and have it clunk through each second of time and print out the speed [v] and current distance [x] from the starting line, using v=at and x=0.5a(t^2) repeatedly.

It turns out that you also need the RPM/torque curve for the motor and for a DC motor this is a straight line, with max torque with a locked rotor and zero torque at top speed and max power at half the top speed. Using this with the wheel radius let's you calc. force [f] which you need for f=ma, where m is the vehicle mass in appropriate units.

When I get this thing debugged I'll post it. It should work for any RPM/torque curve. If you use a transmission, accelerate on an incline or take air resistance into account it'll be a few more lines in the spreadsheet.


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## Rational (Nov 26, 2011)

It seems to work. With a wheel radius of 1', 322 pounds vehicle + driver, torque curve that goes from 40 lb-ft to zero in 10 seconds, it gives me a max speed of 15 mph reached at 143' from the starting line and max hp is 0.59 at a torque of 24 lb-ft.

What I need now is real world data that confirms/disproves this algorithm.


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## anand.ssukhi (Jul 23, 2009)

Wow, these are good stats for a motor on any hybrid bike, coz it always has an engine to assist.

now i would like to know how to convert an alternator to motor,
would a bldc controller be able to control the alternator as a motor ( armature winding shall be separately controlled)


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## Salty9 (Jul 13, 2009)

Check http://endless-sphere.com/forums/viewtopic.php?f=30&t=16328

and http://www.diyelectriccar.com/forums/showthread.php?t=23799&highlight=alternator+controller


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## anand.ssukhi (Jul 23, 2009)

Thanx salty, the thread on endless sphere is really helpful, i think i will go for a sensorless esc with field control, as i dont need to drive alternator for long as an motor, it is still going to be the alternator part which will be used more..


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## Salty9 (Jul 13, 2009)

Check the posts by IneptOne in http://www.rcgroups.com/forums/showthread.php?t=1123956&highlight=reem. He does a detailed analysis of an alternator used as a motor and reaches an interesting estimate of the possible power. Note that he determined that the rotor saturates at about 2 amps current.


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## anand.ssukhi (Jul 23, 2009)

I was thinking of controlling stator frequency in the cheapest way and i had an idea:

cpu cooling fans are bldc fans with pwm control, operating in 5-12 volts range and with max 1 amp current, what if i use the supply going to motor coil to fire the power transistors????
I dont need very accurate speed control, i just need a rotating magnetic field in the stator and somewhat control over the speed of rotation of the field..

would this work??


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## Salty9 (Jul 13, 2009)

anand.ssukhi said:


> I was thinking of controlling stator frequency in the cheapest way and i had an idea:
> 
> cpu cooling fans are bldc fans with pwm control, operating in 5-12 volts range and with max 1 amp current, what if i use the supply going to motor coil to fire the power transistors????
> I dont need very accurate speed control, i just need a rotating magnetic field in the stator and somewhat control over the speed of rotation of the field..
> ...


I don't know. You could try it. I think you need more precise control of the stator for effective use. Let us know how it turns out.


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## anand.ssukhi (Jul 23, 2009)

I dont think I would be needing much precise control, as the motor would be needed only for accelrating,
suppose u change gear on bike, the time for which u need a higher throttle to bring up engine rpm to normal, so it would just be a few seconds, ( requirments such as an series DC motor).


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## anand.ssukhi (Jul 23, 2009)

Checked the cpu fan motor, it ir 4 pole 2 phase bldc motor, so it wont work,
But i also came to know the cd/dvd drive motors are 9 pole 3phase bldc motors,
guess this would work...


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