50cc bicycle motor kits

[trikeman]

Has anyone here ever built one of these little (50cc) gas powered bikes? The appear to have a sprocket mounted on the opposite of the freewheel on the regular bike rear wheel, but I can't figure out how it attaches. Is it flimsy?

http://i288.photobucket.com/albums/ll198/raneyd_photos/MotorBicycle1041.jpg

From this picture, it looks like they mount to the spokes:

http://motoredbikes.com/attachment.php?attachmentid=5622&d=1207002506

[AtomicZombie]

Yes, there is a backing plate and some rubber between the sprocket. It does seem like a bad system, but I have seen these things going down the street, so I guess it holds up.

Cops do not like these bike around here, and they are very noisy. They do move quite fast, but are bad on huge hills.

Brad

[n9viw]

I'd been considering a similar mounting system for a disk brake on non-disk-brake-ready wheels. If I used sufficient bolts and a spacer, do you think the hub and spokes could take the torque that a disk on full-brake would deliver?

[trikeman]

I'd been considering a similar mounting system for a disk brake on non-disk-brake-ready wheels. If I used sufficient bolts and a spacer, do you think the hub and spokes could take the torque that a disk on full-brake would deliver?


Well lots of people seem to be running those 49-80cc gas motors with that setup holding the sprocket, so it should hold a brake too if you can space it out enough to get your caliper on it. I am not sure how they center the whole thing, but that is the way many of the kit motors come.

[trikeman]

I'd been considering a similar mounting system for a disk brake on non-disk-brake-ready wheels. If I used sufficient bolts and a spacer, do you think the hub and spokes could take the torque that a disk on full-brake would deliver?


Well lots of people seem to be running those 49-80cc gas motors with that holding the sprocket, so it should hold a brake too. I am not sure how they center the whole thing, but that is the way many of the kit motors come.

Many are mounting them on this $99 Walmart Moon Dog. I looked at one today in the Walmart (without the engine mod). Cool doner bike if you need big tires and a beefy frame without suspension. The Walmart cruiser type Schwinn is made better, but its about $50 more.

http://farm3.static.flickr.com/2232/2508572461_848e4ef017_o.jpg

http://www.motoredbikes.com/attachment.php?attachmentid=7214&d=1211686836

The Moon Dog frame just needs about a foot of tubing welding in to make it longer and maybe a better front end - I gotta quit looking at these things, or I may end up building a retro motorbike.

[AtomicZombie]

I don't think that will be safe.

Braking forces are WAY higher then the forces that could be applied by your legs or by an assist motor.

Think of it this way....

If it takes you or your motor 10 seconds to get up to 30 miles per hour, it will probably only take your brakes 2 seconds to stop you.

This means that your wheels must endure 5 times the force during braking. A disc brake makes things even worse as it transmits all the energy through the hub flange and spokes. A pad brake only effects the rim and tire.

Brad




I'd been considering a similar mounting system for a disk brake on non-disk-brake-ready wheels. If I used sufficient bolts and a spacer, do you think the hub and spokes could take the torque that a disk on full-brake would deliver?

[rkattufts]

Yeah, that looks bad.

Not as bad as these though...

http://www.instructables.com/id/Go-llerblades:-Motorized-Skates---Part-1/
http://www.tricrides.com/motosks_buy.htm
www.theishoes.com (http://www.theishoes.com)

Brakes? Brakes are for the weak!

[Sparky]

i was interested in those engine kits, but convinced myself i didnt want one.

first off, here in N.C., legal limit is 50 cc. alot of those are 80. also, searching on youtube ive found lots of vids of em- they are loud, they sound like motorcycles. which, i guess, they are. and they are fast. dont know about yall, but i really dont want an engine on my bike pushing me to 50mph.

my next project will be to mount up a little weedeater motor over the back tire, with a friction drive. also noisy, but not like the 80cc ones.

theres another type that uses a belt drive on a BIG pulley that is somehow attached to the back wheel, maybe also by the spokes.

[trikeman]

Unfortunately (or fortunately depending on your viewpoint), it looks like I won't be adding any motors to my bikes anytime soon. I was getting sort of psyched up on building a bike either powered by electric or gasoline. Apparently though, Georgia isn't friendly to motor assisted bicycles. At least that is the way the Forsyth County Sheriff's Office (suburb of Atlanta) interprets the law

http://www.forsythsheriff.org/news/news_040105_scooters.shtml

I guess I will keep driving the gas guzzler for now on trips too far away to pedal. I have ready access to at least 50 miles of bicycle path, but they prohibit motorized vehicles. Still, I figured I could pedal until I wanted to get off the path, then motor to nearby destinations. Looks like I won't be doing that until Georgia decides motorized bicycles are better than SUVs.

You can ride a motorized bicycle on Georgia roads, but you have to make it fully street legal (turn signals, stop lights, DOT approved tires, etc).

[gbbwolf]

I am glad I live in indiana
Mopeds under 50cc or 20 mph have been legal here for quite some time.
I had one 25 years or so ago, an old PUCH moped.
Or should I say PUSH moped.
Pushed it more than I ever rode it I beleive.

Nelson

[trikeman]

mopeds are legal here, but they have to be street legal and registered. I suppose you could make a motorized bicycle street legal, but sounds like a big hassle when I can just buy a motorcycle if I want one. Too bad too - I just picked up a nice old schwinn cruiser similar to my grocer getter. It would have made a nice motor bike.

[trikeman]

Just a little update/correction for those in Georgia considering electric assist bicycles. Apparently an electrically assisted bicycle (Georgia Code 40-1-1) has been granted an exception in the laws on motor vehicles and is considered a bicycle (and not a moped) in Georgia. That means you can ride it on the side of the road without having all the stop lights, turn signals etc that a moped requires. You still have to obey all the traffic laws, just as you do on a bicycle operated on the road.

The laws in some states have been changing in this respect, and I suspect that the Forsythe County Sheriffs interpretation I posted is an old one, or at least wrong. Natually, the web page source contains no date, nor does the underlying code, but hey who needs proper web coding rules? Cops also have guns and a certain "attitude" in many cases, so whatever they believe effectively becomes the law, unless you want to hire a lawyer and/or spend some time in court. An electric assisted bicycle in Georgia can have no more than a 1000W motor and not be capable of speeds that exceed 20 mph.

The law in Georgia also says you can ride an electric assist bicycle on a bike path, but there is some controversy on that. The people (PATH) who administer the path I ride on say no motorized vehicles of any kind. There was a recent court case where a man that needed an electric scooter challenged the rules and won. Still the PATH people contend they don't want motor assists on the trails they fought so hard to get built. I respect the people from PATH immensely, so I would probably respect their wishes.

So the 49cc gasser is probably out, but the Silent Speedster and bicycles like it are probably in. I would not be surprised to find that the local law enforcement is not properly informed, however. The hub motor may still be your best bet for avoiding hassles, in more ways than one.

[gbbwolf]

Just looked into Electric Bikes in Indiana, recent code changes also.
B4 they had to be built just like a moped with turn signals, brake and headlights and a working speedometer.
Also a cutoff switch mounted by the brake lever.

Mopeds under 50 cc do not require registration in Indiana.
But 50 cc and up require not only a title and registration, but a motorcycle license to operate.

Electric assisted bikes have to be under 700 watts, there is a provision in works to allow 1000 watts.
They can do no more than 20 mph and must have a working speedometer.
Guess a bicycle computer that does speed and stuff will work.

Finding The laws in indiana was kinda a chore in itself,
sorting through legislation listed on our .gov website is a pain.

None of it was listed in the bmv handbook or on the bmv website.

Had to read through state legislation papers.

My god those people make laws no one can understand.

Nelson

[AtomicZombie]

When I used to blast arouns on Sparky, I had to hide from "the man", but anything with a hubmotor seems to be no problem. I am thinking about getting a Phoenix Brute hubmotor (1000+ watts) and making a very fast electric recumbent (Meridian style) that also includes pedals. I should be able to outrun city traffic and get an hour run time out of it.

Brad

[Timmy]

These these things are everywhere here in SC.
Hey believe it or not my father had a 50cc Harley Davidson when I was a kid. It was a full sized bike and fast as could be. It wasn't really made by Harley but imported from Italy.
If the engine in that kit is noisy it would be very easy to add a real real muffler to quite it down. I built a 4 into 1 muffler system for an old 350-4 Honda motorcycle I had. I brazed different sized exhaust tubing together and even had a removable baffle so I could replace the fiberglass damping material. Sucker was as quiet as the original.
I'd like to see a v-twin version of the bike motor to mount to a tour easy.

[Sparky]

my dad also has one of those old italian harleys, i used to ride it around the backyard. i sure it was bigger than 50cc, but maybe i am wrong.

anyway, it wouldnt work as a moped/scooter around here- it was a 3 speed and NC state laws are- under 50cc, top speed of 30, and no external shifter

as for a v-twin... well, some creative use of an non-functional extra cylinder and head, run a spark plug wire to it... betcha it would fool most people. :D

[savarin]

our states answer to the gas shortage is the usual dim witted political knee jerk reaction.
They have suddenly banned all types of added engines to bicycles.
Even factory produced legal (or what were legal) machines.
No Warning, no discussion just a blanket ban.

[SirJoey]

our states answer to the gas shortage is the usual dim witted political knee jerk reaction.
They have suddenly banned all types of added engines to bicycles.
Even factory produced legal (or what were legal) machines.
No Warning, no discussion just a blanket ban.

Man, that's so moronic, it's unbelievable! Like trying to douse a fire with gasoline!

http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

[trikeman]

Definitely an over-reaction, but I do have some sympathy for the law makers. Those of use building and repairing bicycles here have often talked about solutions to not having adequate brakes. Imagine what might happen if you strap an engine on a bike with bad (or no) brakes that will propel it on the streets at 35 mph or more. Then, there are things such as working stop lights, headlights, tail lights etc.

When I first learned that if I put a gasoline motor on my old Schwinn in Georgia I would have to have it classified as a moped, register it, and horror-of-horrors, have it inspected by an official to make sure it was road worthy, I was pissed. I am basically a Libertarian in my political leanings, so the thought of the government telling me to do, or not do anything that doesn't harm anyone else is an anathema to me.

But.. the more I thought about it, having to make a vehicle that truly was road worthy is probably for my own good. Last year, two of my sons acquired motor cycles. When one was going for his learners permit to learn to drive the beast, I decided to get one too. I had never ridden a motorcycle before. Driving even a real motorcycle with great brakes, plenty of power to get out of the way, working lights and signals, etc, on the streets with cars was a scary experience for me, and it doesn't take much to convince anyone with sense that it is dangerous, mostly because the cars do really stupid things and if they hit you, you are toast. Being on the road with them on a less than adequate machine is even worse. It doesn't mean they should ban motorcycles (I'd rather ban cars), but minimum safety standards are probably a good thing.

[SirJoey]

...so the thought of the government telling me to do, or not do anything that doesn't harm anyone else is an anathema to me.

I couldn't agree more, TM! Helmet laws immediately come to mind. Sure, it's stupid to ride a motorized vehicle without one, & I personally wouldn't do it, but where do they get off telling me I'm NOT ALLOWED to?

If idiots wanna risk head trauma, they should be allowed to, LOL! Seatbelt laws on children, are a good thing, & should be strictly enforced, however, seatbelt laws on ADULTS, & helmet laws are mainly intended to reap more revenues, than anything else.

Remember folks, you're not allowed risk hurting yourself!

http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

[trikeman]

Speaking of telling us what not to do - my rails to trail trail does not allow riding at night. I am sure it would be more difficult for law enforcement to keep it under control at night. We have had several women raped running or riding by themselves in the daytime even.

I read on one of the trail forums that about 80% of the trail riders are now packing heat, especially the older recumbent riders. I am not sure that is correct, but the concealed weapons laws in Georgia are practically non-existent. My wife and another woman frequently go to dog agility competitions together with their 4 dogs. Both of them got permits to carry a concealed handgun simply by filling out a form. Both are now packing snub nosed 38s and they know how to use them, since they go to the shooting range and practice. I would sure hate to break in on that situation some dark night lol. I see the Supremes decided last week to uphold our right to bear arms.

I carry about $3 a cell phone, and a flimsy bicycle pump as my only weapon.

The trail also runs behind lots of houses, so night time noise could be a problem. Still, it sure would be nice to be able to ride in the cool of the evening on it.