# bicycle motors



## justsayno

Has anyone ever seen someone riding a mountainbike down the street that has a motor attached ? It looks like they can go pretty fast with them. I am looking for information on building this myself somehow, anyone done it? This could be pretty efficient and have a higher ability for me to pick it up over downed logs or go between cars that are blocking things in a survival situation


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## CHUM

justsayno said:


> Has anyone ever seen someone riding a mountainbike down the street that has a motor attached ? It looks like they can go pretty fast with them. I am looking for information on building this myself somehow, anyone done it? This could be pretty efficient and have a higher ability for me to pick it up over downed logs or go between cars that are blocking things in a survival situation


it's called a moped......or, you can actually just pedal a bike yourself......


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## justsayno

this is much cheaper than purchasing a moped.


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## pantser

Where could I get a cheap electric motor if I wanted to make my bicycle run on electricity?


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## spittinfire

I thought this was a nickname for kids....


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## TechAdmin

I've riden an gas powered bike before. Fun stuff. Can't recall the details of it but I wouldn't mind finding one.


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## guyfour

They sold electric mopeds along the side of the road for a long time, it would be a fun project to strip one and hook the go-parts to a bike... while leaving the heavy frame / plastic covering off to reduce energy consumption


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## Smithy

These are they guys you want to talk to, then...

http://www.motoredbikes.com/

Good luck. I plan on doing one next year.


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## TechAdmin

Do they make bikes that charge the battery with pedal power and then you can switch on the electric motor when you want?


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## Smithy

They used to sell dynamo-powered headlights for bicycles, I don't see why you couldn't hook one up as a trickle charger to the battery pack... but the voltage sure wouldn't be consistant, and I'm not an electrician. If you know some Radio Shack Dork, they might be able to help you. 

I'll call it "Possible".


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## dragonfly

Are all of the "motorize your bicycle" kits really expensive? I was looking at them the other day and it was typically like $550 just for a motor / gas tank / throttle / fuel line and some clamps plus the sprocket adapter. Are there any free DIY plans on the internet where you can just take apart a weed eater and use those parts for cheaper?


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## Smithy

Not really. The 50cc kit goes for $200 or less, shipped. If they're asking more, they're ripping you off or offering the cycle as well, usually an upscale "pretty" model. The engine stuff, bought separately for a bike you already own, is cheap, especially when you consider the mileage and utility of such a vehicle.

Here's one on ebay: http://cgi.ebay.com/80CC-MOTOR-bicy...39:1|66:2|65:12|240:1308&_trksid=p3286.c0.m14


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## Prince

Could that go on a bmx sized bike also or a mountainbike? It looks like it only goes on roadster style bikes or whatever you call them. Also that kit might come with instructions in hard to read engrish.


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## billythekid

Whats the best way to find out if riding a bicycle with a motor on it is legal in my area?


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## TheBlackRabbit

billythekid said:


> Whats the best way to find out if riding a bicycle with a motor on it is legal in my area?


Why worry? you can ride a regular bike on the streets anyway. Going a little faster would be safer IMO. And cars would hate you less.


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## digapony

LOL You could get a ticket around here


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## TechAdmin

There is some law that anything under 50cc doesn't require much. I remember selling a 49CC moped to guy who couldn't drive because he had a DWI and had to have a motorcycle under 50cc.


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## Smithy

The law can vary by state, but largely it is true that under 50cc, no license or registration is required, and the moped (motorized bicycle) may be ridden on streets other than highway or Interstate. This is a rule of thumb, but just google your "state" and "motorized bicycle laws" and you'll come up with better guidance than this catch-all.

@ Prince, I don't know about a BMX... mountain bikes, probably yes. Just look at the space the engine requires, and have round tube frame... I think 1 inch or so.


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## ke4sky

*Virginia DMV - Facts About Mopeds and Scooters*

First, make sure your scooter or moped fits the following criteria:

Has not more than three wheels that are in contact with the road.
Has a seat that is no less than 24 inches in height.

Has a gasoline, electric, or hybrid motor that is less than 50 cubic centimeters (cc) and a maximum speed of less than 30 mph.

If your moped or scooter meets the above definitions you do not need to register it.

*Restrictions for Mopeds and Scooters*

No moped/scooter may be driven on any highway where the speed limit is faster than 35 mph.

Riders must be at least 16 years of age and obey all rules of the road.
Every driver must carry a form of identification that includes his/her name, address, and date of birth.

It is against the law to operate a moped while using earphones.

*Other Laws*

*If your moped or scooter has an engine displacement of 51 cc or more and the maximum speed is over 35 mph, you are required to obtain a motorcycle endorsement on your driver's license to ride on Virginia highways. You will also be required to title and register it as a motorcycle.*

Register it by bringing the following to any DMV customer service center:

A completed Application for Certificate of Title and Registration.
Proof of ownership in the form of a title, a manufacturer's certificate or origin, or a Bill of Sale.
Proof of address.
Check, cash or credit card to pay the $10 titling fee.
Remember, laws can vary by locality. Be sure to check other requirements that may be in effect in various cities, towns, counties or states.


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## carnut1100

MOTORISED BICYCLE ENGINE KIT ZBOX BIKE MOTOR AUSTRALIA 48cc MOPED - AUD$235
These guys have a reasonable website with tips and tricks etc, even though you would probably get the kits cheaper directly in the US. 
Worth a read.


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## The_Blob

spend a little more money and get a 4-stroke engine, they're worth it 

First some explanation on how both the 4-stroke & 2-stroke engines work: 

In a 4-stroke engine, when the piston moves down fresh air and gas is sucked inside the cylinder from the carburetor. When the piston moves up again the valves are closed and the air is being compressed. When the piston reaches it's highest position the sparkplug produces a spark that ignites the fumes and causes an explosion. Because of the power of the explosion the piston is pushed back. When the piston moves back up again the exhaust valve is open and the fumes are pushed out the cylinder. Now the whole process restarts (exactly after 4 strokes. That's why we call it a 4-stroke engine...   ). 

The 2-stroke engine works a little different. It performs 2 strokes at the same time (twice) so after only 2 strokes the whole process restarts. A two stroke engine uses the space above and below the piston. Below the piston are fresh gases, above the piston these gases are ignited. Assume the piston is in the lowest position with fresh gases in the cylinder above it. When the piston moves up, these gases are compressed, but at the same time the air pressure below the piston drops and fresh air is sucked inside. When the piston is in it's highest position the sparkplug ignites the gases and the piston is pushed down. About halfway down a channel from the fresh gases to the exhaust gases opens and a channel to the exhaust. Because of air pressure differences the fresh gases flow inside the cylinder pushing the exhaust fumes out. Now the process starts again. As you can see this only took 2 strokes. 


- Two-stroke engines don't live as long as four-stroke engines. The lack of a dedicated lubrication system means that the parts of a two-stroke engine wear-out faster. Two-stroke engines require a mix of oil in with the gas to lubricate the crankshaft, connecting rod and cylinder walls.
- Two-stroke oil can be expensive. Mixing ratio is about 4 ounces per gallon of gas: burning about a gallon of oil every 1,000 miles.
- Two-stroke engines only produce significant power at 9k-12k rpm which is why most are set at "1,000,000 angry bees level" 
- Two-stroke engines do not use fuel efficiently, yielding fewer miles per gallon*.
- Two-stroke engines produce more pollution**.

*a stock 2-stroke bike uses bbout 1 liter fuel per 35km. Whereas a stock 4-stroke bike uses about 1 liter fuel per 60km!

**The combustion of the oil in the gas. The oil makes all two-stroke engines smoky to some extent, and a badly worn two-stroke engine can emit more oily smoke. Each time a new mix of air/fuel is loaded into the combustion chamber, part of it leaks out through the exhaust port.


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## carnut1100

But 2 strokes go harder for the same size engine, due to twice the number of power strokes...
4 stroke is more efficient, less vibration, quieter, longer lived, less fuss with no oil mixing, but they are also heavier and bulkier for the same output, and if you are limited in capacity, say 50cc, then the 2 stroke will go harder.


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## The_Blob

carnut1100 said:


> But 2 strokes go harder for the same size engine, due to twice the number of power strokes...
> 4 stroke is more efficient, less vibration, quieter, longer lived, less fuss with no oil mixing, but they are also heavier and bulkier for the same output, and if you are limited in capacity, say 50cc, then the 2 stroke will go harder.


they do have more power, but _*only*_ at a _*much*_ higher RPM, that's why whenever you see a 2-stroker it is almost always _*screaming*_  
hence the "1,000,000 screaming bees" comment


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## MSGarden

*Husband put a few togethter*

My husband put a few bikes with gas motors together a few summers ago.

We went over 200 miles on them around the country side (boy was my butt sore). But I loved it- up hills, peddle through town, easy to manage. and 80 or more MPG. They were quiet, easy to handle.

My issues with them were- I would want a 3 or 4 wheeler for more stability on back gravel roads and more comfortable seating; They can go pretty fast and a whip-out could be pretty bad.

We have some links to pictures on MyBackAchers.com He likes to recycle old bikes and put motors on them for sale.


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## kettleMan

Dean said:


> There is some law that anything under 50cc doesn't require much. I remember selling a 49CC moped to guy who couldn't drive because he had a DWI and had to have a motorcycle under 50cc.


Interesting....


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## vja4Him

There are specific laws regarding bicycles with motors. You need to look up the laws for your area. I believe where I live (California) that you can only go up to 20mph with a motorized bicycle without a special license.

I did a lot of research on motorized bicycles and was seriously considering motorizing my Electra Townie. I'm glad that I didn't!

I would prefer an electric motor for my bicycle, and I want the extra heavy-duty long-lasting batteries, which would cost around $2000 (that's two thousand!) dollars ... !!!

Plus I would need a heavy-duty controller. There are people who have rigged their bicycles to go very fast! One guy in England, I think his name is Cedric, built his own motor, which has been produced for sale to the public. Can't remember the name .... Do a search and You will find the motor that he designed.

Cedric's specially built electric bicycle will attain speeds of 50-60 mph!!! And he gets between 150-200 miles on each charge!!! That is one awesome bicycle!!!


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## vja4Him

*Cedric Lynch Electric Bicycle*

Here is the video I was looking for:

Cedric Lynch and Agni Motors - The Legend (w/Video) | Electric Vehicle News

Cedric gives more details about his electric bicycle.


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