Gas generator powered ebike with AC motor?
#1
Newbie
Thread Starter
Join Date: Jul 2018
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Gas generator powered ebike with AC motor?
Where I live there is a restriction on Ebikes to 750 watts or 1 hp. I just so happen to have a 1hp 120v AC motor. Heavy duty rated for continuous use. So in theory can I plug that motor in to a small cheap gasoline generator, and use it to power a bike or trike? Im planning to just skip the whole battery thing, and run it direct. Can anyone see any problems i may have with this setup? I intend to use this for longer distance camping/hunting trips. to haul gear and whatnot.
#3
Senior Member
Join Date: Nov 2014
Location: Eugene, Oregon, USA
Posts: 27,547
Mentioned: 217 Post(s)
Tagged: 0 Thread(s)
Quoted: 18395 Post(s)
Liked 4,521 Times
in
3,359 Posts
Hmmm...
It probably would work.
I'd look for a good 3 phase motor and 3 phase variable frequency drive.
But, the whole gas/electric system seems a bit redundant. One option would be to make it like a hybrid, with the generator charging the battery which runs the motor. Thus you can run the generator at a constant rate, and use a bit more or less power as needs require.
Running it at times in full E-Bike mode would get around complaints that it is a gas bike with a electric coupled transmission.
It probably would work.
I'd look for a good 3 phase motor and 3 phase variable frequency drive.
But, the whole gas/electric system seems a bit redundant. One option would be to make it like a hybrid, with the generator charging the battery which runs the motor. Thus you can run the generator at a constant rate, and use a bit more or less power as needs require.
Running it at times in full E-Bike mode would get around complaints that it is a gas bike with a electric coupled transmission.
#4
Senior Member
Join Date: Jul 2014
Location: socal
Posts: 4,275
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 885 Post(s)
Liked 827 Times
in
625 Posts
+1 with CK, but watch out for the "greenies" who might point out that you are using an inefficient gas engine to charge a battery (probably somewhat inefficiently) to power an electric motor relatively efficiently (85% or so if the data are correct). Please note this analysis is from a Chemist, not a smart person.
#5
Cycleway town
I considered this myself and couldn't see a legal issue. There is no law against carrying a generator. There is no law stating how your e-bike get's it's electricity. The law states the bike must be powered by the electric motor, it must be 250watts, pedal assisted, and restricted to 15.5mph in the UK. The generator is not propelling the vehicle itself.
Generators are quite weighty, given the amps you'll need, and i struggled to find one that'd put out the required wattage for that ampage. If you can find one small and light that'd do 20A at 24v then that'd probably be the best route, as finding 36v is likely to prove trickier.
Generators are quite weighty, given the amps you'll need, and i struggled to find one that'd put out the required wattage for that ampage. If you can find one small and light that'd do 20A at 24v then that'd probably be the best route, as finding 36v is likely to prove trickier.
#6
Senior Member
Join Date: Nov 2014
Location: Eugene, Oregon, USA
Posts: 27,547
Mentioned: 217 Post(s)
Tagged: 0 Thread(s)
Quoted: 18395 Post(s)
Liked 4,521 Times
in
3,359 Posts
I considered this myself and couldn't see a legal issue. There is no law against carrying a generator. There is no law stating how your e-bike get's it's electricity. The law states the bike must be powered by the electric motor, it must be 250watts, pedal assisted, and restricted to 15.5mph in the UK. The generator is not propelling the vehicle itself.
Generators are quite weighty, given the amps you'll need, and i struggled to find one that'd put out the required wattage for that ampage. If you can find one small and light that'd do 20A at 24v then that'd probably be the best route, as finding 36v is likely to prove trickier.
Generators are quite weighty, given the amps you'll need, and i struggled to find one that'd put out the required wattage for that ampage. If you can find one small and light that'd do 20A at 24v then that'd probably be the best route, as finding 36v is likely to prove trickier.
I think there are some small 350 to 500W generators. 2 cycle? 4 cycle? They are light and compact.
Of course, 1 HP continuous will require somewhere between 1KW and 1.5 KW. But, intermittent with battery, it should be able to use a bit less.
One issue I ran into with small generators is that their DC output was generally very limited. Maybe 8A, 12V. One had to use 110V (or 220V) to get their full output power. And, thus more power conversion to whatever the battery bank requires.
#7
Nigel
Join Date: Mar 2011
Location: San Jose, CA
Posts: 2,991
Bikes: 1980s and 1990s steel: CyclePro, Nishiki, Schwinn, SR, Trek........
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 384 Post(s)
Likes: 0
Liked 6 Times
in
6 Posts
Where I live there is a restriction on Ebikes to 750 watts or 1 hp. I just so happen to have a 1hp 120v AC motor. Heavy duty rated for continuous use. So in theory can I plug that motor in to a small cheap gasoline generator, and use it to power a bike or trike? Im planning to just skip the whole battery thing, and run it direct. Can anyone see any problems i may have with this setup? I intend to use this for longer distance camping/hunting trips. to haul gear and whatnot.
How do you plan on controlling the output of the motor? What style of AC motor is it? ref: https://en.wikipedia.org/wiki/AC_motor
There are almost as many control types as there are types o AC motor. Some are practical for use in powered vehicles.
Advantages of having batteries:
* you don't need to run the ic engine all the time.
* you can get away with a smaller generator because it is highly unlikely that you will be going flat out all the time (the police would notice you racing along at over 30mph).
* reference: research studies on the optimal size for a hybrid vehicle's battery system.
A BLDC motor (very common for ebike use) is a sort of AC motor, it is fed 3 phase variable frequency AC, usually synchronized by Hall effect sensors. It can just as easily be fed 50/60 Hz three phase and would spin at a constant speed.
#8
Newbie
Thread Starter
Join Date: Jul 2018
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
How do you plan on controlling the output of the motor? What style of AC motor is it?
There are almost as many control types as there are types o AC motor. Some are practical for use in powered vehicles.
Advantages of having batteries:
* you don't need to run the ic engine all the time.
* you can get away with a smaller generator because it is highly unlikely that you will be going flat out all the time (the police would notice you racing along at over 30mph).
* reference: research studies on the optimal size for a hybrid vehicle's battery system.
A BLDC motor (very common for ebike use) is a sort of AC motor, it is fed 3 phase variable frequency AC, usually synchronized by Hall effect sensors. It can just as easily be fed 50/60 Hz three phase and would spin at a constant speed.
There are almost as many control types as there are types o AC motor. Some are practical for use in powered vehicles.
Advantages of having batteries:
* you don't need to run the ic engine all the time.
* you can get away with a smaller generator because it is highly unlikely that you will be going flat out all the time (the police would notice you racing along at over 30mph).
* reference: research studies on the optimal size for a hybrid vehicle's battery system.
A BLDC motor (very common for ebike use) is a sort of AC motor, it is fed 3 phase variable frequency AC, usually synchronized by Hall effect sensors. It can just as easily be fed 50/60 Hz three phase and would spin at a constant speed.
#9
Nigel
Join Date: Mar 2011
Location: San Jose, CA
Posts: 2,991
Bikes: 1980s and 1990s steel: CyclePro, Nishiki, Schwinn, SR, Trek........
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 384 Post(s)
Likes: 0
Liked 6 Times
in
6 Posts
Until you determine this, and then learn how control that type of motor, the project is not going anywhere.
How fast does the motor spin? Is the speed frequency dependent? Many AC motors are rated for just under 3600 rpm (like 3450) at 60 Hz and just under 3000 rpm at 50 Hz. The just under is because they slip to produce torque, the output speed is dependent on the torque taken from the motor, it will try to get to its sync speed (for example 3600 rpm at 60 Hz, but it produces no torque at that speed).
To go ~10 mph, you need to spin the wheel at about 120 rpm; 30:1 gearing is non-trivial. It would be less expensive to purchase a hub motor wheel kit than a 30:1 reduction system that will survive the torque required for meaningful assist on a bike.
How fast does the motor spin? Is the speed frequency dependent? Many AC motors are rated for just under 3600 rpm (like 3450) at 60 Hz and just under 3000 rpm at 50 Hz. The just under is because they slip to produce torque, the output speed is dependent on the torque taken from the motor, it will try to get to its sync speed (for example 3600 rpm at 60 Hz, but it produces no torque at that speed).
To go ~10 mph, you need to spin the wheel at about 120 rpm; 30:1 gearing is non-trivial. It would be less expensive to purchase a hub motor wheel kit than a 30:1 reduction system that will survive the torque required for meaningful assist on a bike.
#10
Randomhead
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,406
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,705 Times
in
2,524 Posts
that's really not a suitable motor for speed control. It can be done, but it's not going to be light or cheap. Far better to get a retrofit kit that is made for purpose. I have worked in motor control and have a collection of small brushless motors and I have considered trying to use one of them. But it's just not worth it with the systems I can buy that already have all the engineering done.
I also don't think the power source is the important part of the legal power limit. So just because it's coming from a generator doesn't mean you can cheat on the limit. If I were really worried about it, I would just take the name plate off of it. You probably aren't going to get 1hp out of that motor anyway.
I also don't think the power source is the important part of the legal power limit. So just because it's coming from a generator doesn't mean you can cheat on the limit. If I were really worried about it, I would just take the name plate off of it. You probably aren't going to get 1hp out of that motor anyway.
#11
Member
Join Date: Jun 2016
Posts: 48
Bikes: Montague Swissbike X50
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Not quite the same, but this was recently posted to a popular site which bills itself as "the front page of the internet" (original at: https://www.jankyshack.com/wp-content...801_151622.jpg ):
#12
Senior Member
Join Date: Nov 2014
Location: Eugene, Oregon, USA
Posts: 27,547
Mentioned: 217 Post(s)
Tagged: 0 Thread(s)
Quoted: 18395 Post(s)
Liked 4,521 Times
in
3,359 Posts
You might get away with a pure E-Bike.
If someone hears your gas powered bike motoring down the trail, you will get reported to the local forest rangers or local law enforcement.
I'd also be annoyed if I had hiked 10 miles in, and some showed up with a noisy generator (and E-Bike).
Last edited by CliffordK; 08-02-18 at 07:34 PM.
#13
Senior Member
Join Date: Nov 2014
Location: Eugene, Oregon, USA
Posts: 27,547
Mentioned: 217 Post(s)
Tagged: 0 Thread(s)
Quoted: 18395 Post(s)
Liked 4,521 Times
in
3,359 Posts
When I was driving an electric vehicle for a while, I did start thinking about a gas generator as a range extender.
My idea was to just fix up a small trailer with a small gas or diesel generator that generated, say half the power my pickup consumed.
So, say I had a range of about 50 miles. By using the 50% generator, I could likely push that 50 miles to 100 or so pretty easily. There would be less of a chance of getting stuck with a dead battery, and overnight, I could do a full recharge.
If you had a camping E-Bike. Then around town, just use the E-Bike. When you're ready for an overnight trip, grab the trailer and take off. Camp at the trailhead and fully charge. Then head out into the mountains, battery only. On your way out, camp at the trailhead again, recharge, then head home.
A small solar panel may also help.
Might as well also add an auxiliary battery and fuel tank to your range extender trailer.
My idea was to just fix up a small trailer with a small gas or diesel generator that generated, say half the power my pickup consumed.
So, say I had a range of about 50 miles. By using the 50% generator, I could likely push that 50 miles to 100 or so pretty easily. There would be less of a chance of getting stuck with a dead battery, and overnight, I could do a full recharge.
If you had a camping E-Bike. Then around town, just use the E-Bike. When you're ready for an overnight trip, grab the trailer and take off. Camp at the trailhead and fully charge. Then head out into the mountains, battery only. On your way out, camp at the trailhead again, recharge, then head home.
A small solar panel may also help.
Might as well also add an auxiliary battery and fuel tank to your range extender trailer.
Last edited by CliffordK; 08-02-18 at 07:32 PM.
#14
Senior Member
Not quite the same, but this was recently posted to a popular site which bills itself as "the front page of the internet" (original at: https://www.jankyshack.com/wp-content...801_151622.jpg ):
#15
Nigel
Join Date: Mar 2011
Location: San Jose, CA
Posts: 2,991
Bikes: 1980s and 1990s steel: CyclePro, Nishiki, Schwinn, SR, Trek........
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 384 Post(s)
Likes: 0
Liked 6 Times
in
6 Posts
#16
Senior Member
Join Date: Nov 2014
Location: Eugene, Oregon, USA
Posts: 27,547
Mentioned: 217 Post(s)
Tagged: 0 Thread(s)
Quoted: 18395 Post(s)
Liked 4,521 Times
in
3,359 Posts
Like this: Mr.Sharkey's Pusher Trailer ?
I think a pusher trailer pushes.
A generator trailer supplies power to the battery/electric motor.
I think pushers are not uncommon for heavy cargo bikes, but I'm not sure I'd want to use one on a lightweight bike.
#17
Senior Member
Join Date: Jul 2005
Posts: 6,002
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 2501 Post(s)
Liked 745 Times
in
526 Posts
It would not. A very large solar panel. Like an entire roof top worth of surface area, now you are talking. If the o.p. wants a range extender, the most practical idea is to use the trailer to carry extra battery capacity. Most generators are not built with mobility in mind so they are unnecessarily heavy. A motor designed for 110V AC is also not going to be a willing participant in the project. It will not have the proper hardpoints to be mounted on the bicycle, or on the trailer for that matter, and it will be twice as heavy as it needs to be. Overweight generator+ overweight motor+ kludgy drive system = failure.
#18
Full Member
Join Date: Jan 2014
Location: Whitestone,Queens/Bayonne N.J.
Posts: 344
Bikes: Aurelia*Bianchi*Cannondale*Colnago*Dahon*Giant*Haro*Lynsky*Monkey Faction*Origin8*Panasonic*Paramont*Peugeot*Ross*Schwinn*SE*Specialized*Trek
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Liked 26 Times
in
18 Posts
There is a legally blind gentleman on YouTube with a trike similar to what you would like to do.It is custom built so he can go long distance without the need of a license since it only does the federally allowed speed limit.
#19
Senior Member
Join Date: Jun 2015
Location: Down Under
Posts: 1,936
Bikes: A steel framed 26" off road tourer from a manufacturer who thinks they are cool. Giant Anthem. Trek 720 Multiroad pub bike. 10 kids bikes all under 20". Assorted waifs and unfinished projects.
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 1188 Post(s)
Liked 1,154 Times
in
640 Posts
Good chance that is a squirrel cage motor, in which case the start up current will be higher than the running current, so your generator would need to be twice as big as the motor rating would suggest...
#21
41 calories/30 min typing
Join Date: May 2018
Posts: 97
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Not quite the same, but this was recently posted to a popular site which bills itself as "the front page of the internet" (original at: https://www.jankyshack.com/wp-content...801_151622.jpg ):
I've got a small coal burning oven. Where can we fit this in?
#22
Randomhead
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,406
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,705 Times
in
2,524 Posts
Number one rule of bicycle design is that every possible bicycle-related invention already exists, regardless of merit. Colin Furze made a jet powered bicycle, and you can find youtubes of a steam powered bicycle made in the last few years.
#23
41 calories/30 min typing
Join Date: May 2018
Posts: 97
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Yeah, but clean coal is the future! The FUTURE! I tells ya!
#24
Randomhead
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,406
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,705 Times
in
2,524 Posts
I'm reasonably sure the steam bike is powered by coal. Jet is powered by propane, but coal slurry has been used as a jet fuel in the past.
#25
Banned
On the river shore we have an old electric trolley ,
but without the overhead electric power lines,
it has a motor-generator, car , pulled in one direction ,
pushed in the opposite direction..
but without the overhead electric power lines,
it has a motor-generator, car , pulled in one direction ,
pushed in the opposite direction..