Motorized Bicycle Forum | MotoredBikes.com
Motorized Bicycle Engine Kit Forum

Great story. Stuff like that should be part of every kid's experience. It would put a huge dent in the drug dealers' and psychiatrists' incomes.

Of course it's possible to motorize a bicycle. That's pretty much how motorcycles were born.
Trouble is, once you have something that's reliable to use at motorcycle speeds, well, then it'll look and weigh like a motorcycle.
Motorcycles and scooters aren't overbuilt for the fun of it, they're built the way they are pretty much because that's how they need to look.
Proven both through experience and analysis.
The reason why the speed/power limited electric bikes gets away with still looking like bikes is that they still stay in the same speed range as a non motorized bike.
Meaning the energy the brakes have to soak up doesn't change, impact from potholes etc also stays the same.
Average speed might go up, but top speed doesn't change.

Now, if you slap a gas engine on, you are likely to see a higher top speed too, and this is where physics bares its teeth and prepares to bite you.
Energy increase isn't the same as speed increase.
Roughly, going 20% faster gives you 50% more kinetic energy.
Double the speed quadruples the kinetic energy. Bad news for brakes, and the whole structure.

Doable, sure. But not the way to build a safe, reliable vehicle for everyday use by any one.

If you're going to do a cross country tour, the great majority of your trip will be on flat or rolling roads. The weight of the motor etc will really make you suffer as you are trying to pedal on those roads for several hours a day. The benefit of the motor when going up hills won't be worth the disadvantages the rest of the time.

Yup. That's why e-bikes are a niche market. If OP needs a motor, he's better off buying a real motorcycle and getting licensed and insured for it. He'll be a lot happier than trying to kludge a bike into something it isn't meant to be.

Mopeds, motorized bikes and add-on kits have been around for a long long time. So yes lots of people have done it.

It's not a big deal if you don't mind riding an illegal motorized bike. The size and speed limits serve the purpose of keeping the bike at a safe speed so that you do not endanger others.

Probably a 2 stroke engine which requires either filling separate tank with oil or mixing oil and gas. For trips be sure to take an extra plug. Doubt that you will find a twin in this size.

It probably has a short exhaust which will be loud. Buy a real motorcycle and solve many of your complaints. Or get in shape and ride a bike up and down the hills.

Yes, they pollute like crazy. It would concern me. How about you?

I don't know if those tire drive setups are designed to run on knobby tires. I would think the smoother the better.



A motorized bike is a poor compromise. Realize that if you plan on doing long distance riding around the country, over mountains and across the desert that your vehicle will have several limitations. 1. It will be very slow and dangerous on an open highway. 2. It has a small fuel tank and off-road use will use fuel like crazy. 3. It will wear out tires so you should carry a spare.

Order one of these .. Dutchman Motorbikes they will do it all for you.

that is completely wrong as there is no emission control at all on a dirty 2 cycle engine. This puts out more pollution than a standard car.

I will personally admit to hating these set ups. they are noisy, smelly and in my area typically ridden by idiots in terms of driving behavior.

The braking, etc that you will have would be sub par for the needs of the power you are adding.

This would not be a good setup for any sort of long distance in terms of comfort and reliability

And as noted in your own post legally (over 80 cc) would require registration, license, insurance etc. This is the type of thing that catches cops eyes.

So many whiners! How sad.

Anyways:
First you need to clarify if this thing will be legal to use wherever you are. You don't have your actual location in your profile, so I couldn't help any with that.

You need to go to your local car-registering-license place and ask them "if I put a motor on a bicycle, can I still use it on public roads?". Don't ask about a 'moped' because [a bicycle with an engine you put on it] may not automatically legally be considered the same as [a moped] (that was manufactured with an engine on it).

A lot of whatever follows hinges on if this would be legal or at least practical to try to use or not....
Even if it's not legal you can still do it anyway. There's lots of horrible things in the world today, but constructing illegal motorized bicycles isn't one of them.

This forum has a motorized bikes sub-forum, but it isn't much good for gas engines.
Motorbicycling.com and motoredbikes.com would have more info.

^ A common bicycle is designed to ride at 15-20kph, 25-30 for short periods. If you ride it at 40kph all day, tires, brake pads, bearings, etc. wear very fast. Bumps are amplified and the frame can break in a short time (I've seen that).

In Michigan your motorized bike would be considered a moped. If it could go over 30 MPH on level ground, or if it required shifting gears, it would be considered a motorcycle (with stricter requirements). A moped has to have headlight, tail light, brakes on both wheels, brake light, and rear view mirror. Every state will likely be different, but I don't think Michigan is too off the norm on these requirements.

A moped is essentially a souped-up bicycle with a motor. They were all the rage in the 1970s when I was growing up.

What sets them apart from motorcycles is they're limited to low speeds and they provide a more nimble ride than a motorcycle.

If you want to ride an engined bike as other posters have already said, buy and ride the real thing.

I know someone who motorized a mountain bike with a small 2-stroke gasoline engine. Some of her experiences: The bike with the motor on it is too heavy to ride only on pedal power. If you're riding her bike, you'll be using the motor. In other words, you won't go any farther than the amount of gasoline you are carrying. Speaking of gasoline, she needs to mix her own two-stroke fuel to get the right amount of oil added. A few other issues - she had to move spacers around on the rear axle and redish the wheel in order to get the drive sprocket on the back wheel lined up perfectly with the sprocket on the motor. Also, on her bike the sprocket on the rear wheel attaches to the spokes! Gentle riding on pavement works but, at least on her bike's setup, off road riding would put way too much torque on the (relatively loose) non-drive side rear wheel spokes. She'd destroy the wheel and have to carry to whole thing out of the woods if she tried riding it off road. BTW - her bike easily exceeds 30 mph. And yes, her's is loud,and the exhaust is really stinky for anyone riding behind her.

This tire-drive motor is only 40cc: Gas Motorized Bicycle 2 Cycle 40cc Tire Roller Drive Rear Mount Bicycle Motor Kit - Live Fast Motors

Do you really need 80cc? The idea behind these bikes is that you supply some of the power. The engine is really just an assist. Is that such a bad thing? Any vehicle that is intended to pull you plus its own weight is (or should be) an actual motorcycle, with much greater HP, structural strength, and weight than a motorized bicycle.

I don't know about the reliability of this motor, though. If you want bullet-proof reliability, get something like a Stihl chainsaw motor and adapt it yourself. https://www.stihlusa.com/WebContent/C...ison-Chart.pdf

I'd be OK with kids just riding bikes.

IBut friction drive is a seriously sucky design. It creates a lot of tire wear, and needs a lot of pressure between roller and tire. Plenty of losses, and unless properly designed, the bearings don't last long.
The trouble with small combustion engines is economy of scale. A small one takes the same number of parts. And surface area vs volume etc makes it harder to get a good burn out of them.
So plenty of reasons to go big(ger). More power, better burn at very close to the same engineering cost.
But sure, a good combustion-assist engine for bikes could have its uses. Maybe a fuel cell?

AGREED! The regulars are usually supportive of people seeking advice. I'm ashamed of many of you for your insults towards the OP.

2 years ago there was a group of motorized bike guys that rode with us o a critical mass ride. They were having fun and they all stayed in the back so nobody could spoil the fun they were having with us.

Yes there may be some set-ups that may be "illegal" but unless you're acting stupid there isnt a cop that would know it was 80cc. Some extra silencing can be done without having to do carburetor changes. ANY kit with tire drive is to be avoided. None of them have ever worked well a all.

Cross country on a machine like this would probably not be fun.

Banggood has a kit for $120. I've thought about getting one just for giggles.

Get one and have some fun with it. Just dont post your smiles in this forum. Post it where others will appreciate it.

Good luck.

-SP

Motorcycles evolved from motorized bikes. Maybe this should have been put in the 'vintage' forum... ;)

The 2-strokes do pollute a lot. Not any more than they ever did, but relatively speaking, it's still a lot for the power they produce. The 4-stroke engines are much better in that regard.

I had a bicycle with a 4-stroke motor kit a few years back, and tried to get a catalytic converter for the engine... and couldn't. The manufacturer was losing money on the catalytic converters, so they would only ship them to dealers in California and I was in Illinois.
(California started requiring lots of small lawn + utility engines to have catalytic converters a few years back)

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The China 2-stroke kits are the cheapest variety and they tend to have a lot of mechanical issues in use. The kits that cost more money will work a lot better/longer.

The 2-stroke bicycle kits were banned in China some years back, for urban smog reasons. (-keep in mind that back then, ZILLIONS of people there were using them-)
The China kits were still legal to export (from China) but many enthusiasts in the US felt that the engine kits decreased in quality in the couple years afterward.

In the early 1960's I had two Whizzer motorbikes (goggle it) which were based on a purpose-built 4-stroke engine designed to bolt (clamp) onto a paperboy bike. They were designed to provide cheap general street/road transportation. Still they had their mechanical weaknesses, resulting in thrown connecting rods despite several factory redesign efforts. That kit you are looking at is a Chinese sorta-copy of the Whizzer theme, but very scaled back. My bet it will be ready for the junk bin after a few hours of use. But try it and report back. BTW, the displacement (cc) is usually marked on the base of the cylinder on moped-type engines, and you should believe the cops would love to catch guys not complying with the very specific (and punitive) moped rules. Google your state's current moped laws - most states have tightened up the moped restrictions in the last year or two. Most do now allow 50cc "motor scooters" capable of less than 35 mph as mopeds even though they don't have pedals. A Chinese 50cc scooter might be a better investment than MTB plus a motor kit.

I've seen a few of those Chinese bike motor conversions in use and they were slow, noisy (think leaf blower) and one spontaneously threw its drive chain, apparently for my simple amusement.

I currently have a Columbia/Sachs moped built in 1978 and it has a German-built 50cc Sachs engine and has wheels, hubs, suspension, brakes, lights and horn like you would see on a small motorcycle. It is street-legal and licensed under our current state moped laws. It's still a little iffy to drive on the street because when cars approach from behind, they usually treat it as a bicycle, and force their way past it anytime and anywhere.

@spectastic, check out this thread in the "Alt Bike Culture" forum: https://www.bikeforums.net/alt-bike-c...34-bringa.html
It looks like the guy started with a "Dutch" bike and ended up with something like and early Harley or Henderson motorcycle. Or more likely the frame was purpose-built - I can't tell.

For Sale 1948 Schwinn Whiizzer- Solvang Vintage Motorcycle Museum, Solvang, CA

We're not under any obligation to cheer ideas we don't like. If the OP wants hugs for strapping a crappy stinky engine onto his bike, he can get them here or on another forum.