Motorized Bicycle Project

[cracker39]

Is anyone building or riding a motorized bicycle these days? I’ve wanted to build one for a couple of years. I am not doing any camping right now due to my wife’s declining health, but when I can go camping again, I think the motorized bike would be ideal for getting around. I also wanted one just for fun riding around the neighborhood and for trips of a mile or less to the library and couple of small stores in our tiny town of Lake Alfred, Florida. I’ve seen at least one of these on my street as well as an engine powered three-wheeler. Recently, I saw two down town in Winter Haven on the same day.

Seeing those mikes made up my mind to begin my bike project over a couple of weeks ago. I looked for a used single speed coaster brake cruiser as my 12 year old 6-speed already has a twist grip shifter and two brake levers on the handlebars and I need to mount a twist throttle and clutch lever for the engine. I found listings for a couple of used cruiser bikes, but they cost so much that I decided to just buy a new one. I ordered a Schwinn Delmar cruiser form Walmart and a Grubee SkyHawn 48cc engine kit from Gasbike.net. Both arrived Thursday and Friday. This is the bike I bought. I'll replace the photo with one of my bike after the assembly is complete.



I made sure that the bicycle was ready by adding more lubricant to the wheel bearings and hubs before beginning it’s transformation to a motorized bike. The engine mounting and adjustments are supposed to take from 4 to 8 hours according to reviews I’ve read, but I will probably spread it out over several days due to various problems that have to be resolved…problems that I expected from reading reviewer’s comments.

One of those problems is having to make an adapter for the engine mount. Once the engine is connected to the seat post, the front mount is about 2” from the front tube, which is a larger diameter than the mount could handle anyway. I’m in the process of fabricating the mount adapter. It will be a few days before I’ll have a photo of the finished bike to post. Another delay in my putting it together is that I’m waiting for a front hand brake to install so I’ll have more stopping power than just the coaster brake.

Meanwhile, I’d love to hear comments or suggestions from folks who have built one of these and see photos of the results.

[48Rob]

Hi Dale,

I've had a couple.

This Web site is a great resource.
http://www.motoredbikes.com/forum.php

My first was a basic kit and basic bike like you are putting together.

It worked well and was a lot of fun.
The engine was a two cycle 48-49cc with clutch, and the bike was a cheap wal mart cruiser.
Rode it a thousand miles or so.

Decided then that I wanted to try one of the automatics (centrifugal clutch).
The engine and clutch came as a kit, with 4 stroke engine.
http://ezmotorbike.com/
http://ezmotorbike.com/?wpsc-product=ezm-complete-kit
I bought a super heavy duty bike made for mounting an engine.

It has the fuel tank built into the frame, heavy duty wheels, brakes, frame, etc.
I've ridden it at least as far, and hope to have it many more years.

Both would run 30-35 mph.
On my current bike, I tossed the small rear sprocket, designed for speed, and remachined a very large exercise bike sprocket to be better able to climb hills.
Now top speed is 25-28 mph, but it takes off from a dead start, and climbs pretty big hills.

The first one cost about $350, and the second about a $1000

Big difference, but then so is the quality and ride/comfort.
I'm tall, and the wal mart bike was pretty small. The new one is much larger/longer.
The old one vibrated badly, and was noisy, the new one doesn't and isn't.

Lots of fun either way, though with the first, a 5 mile ride would wear you out, with the new one 30+ miles at a time is easy.

Some people ask; why don't I just buy a "real" motorcycle?
The answer is because I already have one. It works great for touring and cross country trips, but I also like to buzz around town, and especially like riding at the state parks when we go camping.


The big bike won't fit on the bike carrier on the back of the camping trailer, and I can go a lot of places where bikes are allowed, but motorcycles are not.

We have an older electric bike too, I like it as much as the gas, but it will only go about 12 mph and a few miles before needing a charge, unless you buy super expensive batteries, and a newer style setup.
To get one, you're in the $1500-$2000 range.

Rob

[lancew]

Illinois is such a stickler on these. you never get in trouble from the police ? ride in state parks, I have seen many of times conservation and state police pull over these motorized bicycles. I never built one due to this. well..and I live in Bloomington, this town HATES 2 wheelers.

[48Rob]

Hi Lance,

I have never had a problem in Illinois, Indiana, or Nebraska.

That said, I try to be VERY respectful of the towns and or parks I'm riding in.
I don't speed, drive crazy, or have a loud exhaust like some of the Harley guys that think everyone within 5 miles should hear them revving their engines , and that must have terrible trouble at stoplights with their engines dying, since they keep twising the throttle up and down while they are waiting...

I do my best to follow all the traffic laws, use hand signals, and don't block traffic.
It may also help that I am 53, not 23...?

Rob

[cracker39]

I was careful to read up on Florida's laws regarding motorized bikes. Gas powered bikes with engines of 48CC or less are still considered a bicycle and follow all laws and rules that pertain to bicycles. No insurance or driving license of any kind is required to operate this type of bike in Florida.

Rob, i saw the 48CC 4-cycle engines on Gasbike.com where I ordered my engine kit. They cost over twice the price of my 2-cycle engine. I know that they are smoother running with less vibration, but also at a price. I'm 74 and not looking to go touring on my bike, just a ride of a couple of miles to stores near home. I sure would like the centrifugal clutch though.

I just finished redesigning and fabricating my forward motor mount adapter. I over engineered the first one, so I scrapped the three pieces and made a single piece mount adapter. After it's painted, I'll mount the engine and go from there.

[48Rob]

Dale,

You'll have such a great time, you'll probably feel like a kid again!

Rob

[Dale M.]

You might consider electric.... There are kits available for those too..... I know, not the throb of power from all the 48cc but still viable for short distances...

http://www.electric-bike-kit.com/
http://www.nycewheels.com/conversionkits.html
http://www.bikeberry.com/gas-engine-kit ... -kits.html

Dale M.

[CarlLaFong]

we also got the cab over tiny jap mine trucks roaming the steets . slow

Please do not use that word. It is the same as the "N" word.

[Woodbutcher]

Not as cool as the kits you guys are talking about , but this one is simple and made in the USA. http://bumblebeebolton.com/

[cracker39]

I just finished redesigning and fabricating my forward motor mount adapter. I over engineered the first one, so I scrapped the three pieces and made a single piece mount adapter. After it's painted, I'll mount the engine and go from there.

Well, that one didn't work out so well. The muffler sits very, very close to the front frame tube. My forward motor mount adapter was too wide and pushed the muffler out where it interfered with the pedal crank. I had to remove the engine and adapter, then cut down the adapter width where it meets the frame tube and scrap the U-bolt in favor of a single bolt through a hole drilled in the frame tube and adapter. Before I can remount the engine, I need to buy a single stainless steel bolt to replace the U-bolt. My progress on this project is going to be very slow. It gets too hot too work in my back porch workshop by mid-day and I have to attend to my wif'e's needs periodically as she's ill and can't do much for herself. But, I'm in no hurry anyway as my front hand brake, rear view mirrors and helmet that I ordered have not arrived yet. I'll be happy to have it running by the end of the week.

[48Rob]

Dale,

Please show us your project!

Rob

[GerryS]

Not as cool as the kits you guys are talking about , but this one is simple and made in the USA. http://bumblebeebolton.com/

The trouble with their design is its friction drive.....that's going to mean slipping and tearing up tires.....

I'm suddenly intrigued though, I can't ride my motorcycle any more because of a neck problem (the weight of the helmet, wind buffeting, and vibration) but this might be an alternative....I ride a bicycle fine, the trouble here is I can't ride it from home anywhere because the roads are FAR too busy and too narrow. A motorized kit might give me the 25-30 MPH need to survive the first 5 miles of the trip.

Once I'm past that 5 mile perimeter of what used to be country roads that have been transformed into thoroughfares for subdivisions there are better side street options...

[cracker39]

Dale,

Please show us your project!

Rob

I'd planned on putting together a build journal at some point. I'll get started on that later today.

Gerry, as I understand friction drive, that means two wheels come in contact with the bike wheel to turn it. These engine kits like I have use a chain drive, so I don't think they will adversely affect tires. it's recommended that you upgrade the spokes on the bike wheel to heavier gauge spokes, and I did not, so eventually, there may be spoke problems requiring a new wheel. But with the low miles I'll put on it, probably not for me. I didn't read any reviews or see any videos where anyone replaced their spokes with heavier ones.

[48Rob]

Gerry,

Good plan, but be careful!

Most drivers, especially coming/going to work don't have the time to be patient with bicycles.
You may be screaming down the road at top speed, but to someone in a hurry, you'll just be a very slow irritation.
25-30mph on a bicycle is pretty fast, If someone crowds you onto the shoulder and you find some gravel....

Rob

[cracker39]

"25-30mph on a bicycle is pretty fast, If someone crowds you onto the shoulder and you find some gravel.... "

OUCH!!! I've thought about possibly riding mine into Winter Haven, about a 4-5 mile trip. About a mile and a half to two miles of it is at 50 mph (so cars drive 55-60) and the rest at 45 mph. There is a paved bike/walking path (more like a narrow street) that goes at least half way down the 50 mph section, about 100 feet off the highway. That still leaves more driving on the shoulder in the fast section that I'd like. So, I think I'll just stick to the local streets here in sleepy little Lake Alfred with 25-35 mph limits...Maybe not at "rush hour" when a lot of the local traffic going to and from Orlando and Tampa drive through.