Bicycle Conversion Kits

[GasSavers_maximilian]

Anybody know much about those kits that turn your bicycle into a moped? I saw the link in a gmail ad and followed it. I have no idea what the legalities here in VT would be, but figured I'd see if they were even a good idea to begin with. Thanks.

[GasSavers_BEEF]

somebody on here has done that and said there is a limit of the speed for it not to have to be registered.

25?...35?...45?... miles per hour.

I can't remember but I know that the guy that did it ended up having to register it because of the speed...wait, maybe it was the displacement.

man am I getting old. maybe he will see this and respond.

[GasSavers_Erik]

In many states a scooter/moped engine has to be less than 50cc or it has to be registered.

[GasSavers_maximilian]

The kit I was looking at is 50cc, but it exceeds the 2 hp limit in VT. Looks like the kit operates only at one gear ratio as well, which with our hills is a no go.

[GasSavers_Erik]

Hmm- I wonder how they enforce the 2hp limit? I have heard of police with portable scales to check gravel truck weights- but i have never heard of a portable dyno

Seriously- many small 2 cycle engines have the displacement listed on the side/cast into the cylinder but I have seldom seen the hp listed. Maybe a majic marker could make the hp label illegible

[GasSavers_maximilian]

I wrote the company to find out more details. hehe

[GasSavers_GasUser]

My Son built one. He got the "motor" off e-bay somewheres and it is one really small cylinder. It was a complete kit to motorize a bicycle and included a gas tank and kill switch. Just a clutch to "jump start" the little thing. It is very cheeply made but it worked. Kept breaking the part that goes on the bike sprocket (forget what he called it) and went through 3 mufflers. The bolts holding the bracket on and the bracket were real soft metal. He is doing a couple of changes to it. I think it is around 30cc or somewhere around there and it will do an easy 40mph or so. He rode it to work part of the summer last year when it wasn't being repaired. A gallon of gas lasted him a month. I rode it a couple of times and it is fun. He is currently building another carbon fiber frame for it and going to a couple of mods to it and try it again this year.

He had no trouble with the police or anything and it didn't need to be registered in NY due to the small motor size.

[GasSavers_maximilian]

Originally Posted by GasUser

Kept breaking the part that goes on the bike sprocket (forget what he called it)

The overunning clutch? Part that lets you still pedal? I would think that'd see a lot of stress if made cheaply.

I assume it has just the one gear ratio? Big hills make that tough. I guess a go-kart variable v-belt transmission could be added.

[theholycow]

When I was 12, my go-kart had a centrifugal clutch. More expensive models had torque converters. I suspect that a torque converter made for a small go-kart would suffice for the gearing issue on a motorized bicycle. Those may be difficult to find; I bet a torque converter (or maybe even a CVT) for a snowmobile would be easier to find/cheaper but might be too big/heavy/wrong ratios.

[GasSavers_GasUser]

Originally Posted by maximilian

The overunning clutch? Part that lets you still pedal? I would think that'd see a lot of stress if made cheaply.

I assume it has just the one gear ratio? Big hills make that tough. I guess a go-kart variable v-belt transmission could be added.

It's a nylon/plastic looking round part......pardon my ignorance.

Yea, there is only one speed. No big hills on the route he was riding it so I don't know what it would do on a real hill. I would guess it would probably slow down to a crawl or something. On mild hills it slows down a bit unless you are running it at WAT.......it has an itty bitty carb but a lever where you can adjust the air flow to wide open........you can really get it going good on a straightaway.......haha

I was trying to figure the hp and I came up with around 5 with my fuzzy math so I really have no idea. The motor size was just rated at cc.......no hp mentioned.