Minibike/ "motorized foot scooter"

[foehammer]

Hello,
I am looking for advice regarding a scratch build.
In my state it is illeglal for me to ride a moped so I have to build a "Motorized foot scooter" For urban travel. For some odd reason these scooters are allowed. I am essesinaly going to bend the rules a bit and build a step through mini bike that I can rde to school. The bike wont need to go faster than 25-30 miles an hour. And will need to go up a moderate incline. I am looking for advice on suspension, gear shifting and if my 3 horsepower motor is enough. thanks. (I wont turn away other advice)

---------- Post added at 10:24 PM ---------- Previous post was at 10:22 PM ----------

Edit* The bike does not need to go faster.
The bike needs Nine inch wheels to qualify

---------- Post added at 10:25 PM ---------- Previous post was at 10:24 PM ----------

Edit* The bike does not need to go faster.
The bike needs Nine inch wheels to qualify

 

[landuse]

With only 3HP, I think you are going to struggle to reach the speed you would like.

What is the estimated weight of the bike and rider going to be?

 

[foehammer]

I weigh 80 so 150 in all.

---------- Post added at 08:20 AM ---------- Previous post was at 08:18 AM ----------

maybe 180 since my binder. Also that spped is the speed limit.

---------- Post added at 08:22 AM ---------- Previous post was at 08:20 AM ----------

thanks

 

[itsid]

grain, ounces, lbs, kg, stones, metric tons?

Oh what a dumb question you may ask.. but I weigh 80kgs and that's the units
some of us (well all but americans) measure in.
Since we know nothing about you so far.. we can guess
(kg .. my size...)
or assume you're a ten year old (80 lbs 38kg... normal weight of a 144cm ten yo)

Anyways..
maybe you'd be better off buying a 1600W electric scooter instead..
the "Velocifero MAD" is nice IMHO...
that'd provide a better chance to get you moving I'd say.

'sid

 

[foehammer]

bro I am short also pound sorry.

---------- Post added at 09:11 PM ---------- Previous post was at 08:54 PM ----------

And no I won’t buy anything complete.

 

[Karts of Kaos]

sarcasm. yes absolutely, he definitely ways 80 metric tuns

 

[Functional Artist]

Hello,
I am looking for advice regarding a scratch build.
In my state it is illeglal for me to ride a moped so I have to build a "Motorized foot scooter" For urban travel. For some odd reason these scooters are allowed. I am essesinaly going to bend the rules a bit and build a step through mini bike that I can rde to school. The bike wont need to go faster than 25-30 miles an hour. And will need to go up a moderate incline. I am looking for advice on suspension, gear shifting and if my 3 horsepower motor is enough. thanks. (I wont turn away other advice)

---------- Post added at 10:24 PM ---------- Previous post was at 10:22 PM ----------

Edit* The bike does not need to go faster.
The bike needs Nine inch wheels to qualify

With the type of "basic" questions your asking, I would say you are going to have to do lots of personal research if you want to do a scratch build

Good news is, you came to the right place
...there are lots of minibike builds here on the forum
...but, we cant/aren't gonna do it all for you (or anyone)

You want to "bend the rules" (what rules?)
…& nine inch wheels, on a minibike?

Then, you say that "I won't turn away other advice"
...but when, a suggestion is made, you say "And no I won’t buy anything"

 

[itsid]

a 3hp motor is just not going to work too well..

you'd need a TC at least (but you won't buy one I guess )
and you indeed would have to make the scooter thing super light
(which with a 3horse engine might already be kinda tough)

but if we assume a 150lbs max limit on the weight and 9" wheels and true 3horses industrial style engine (79cc predator or such.. and no; a 39cc weed eater is not a viable alternative)
3.6:1 gear ratio might just work (and even fullfill your speed request.. reaching 29.75mph on flat level road)
the incline is what makes me worry still... 10mph at best uphill I'd say.

 

[foehammer]

Thank You

Thank you for the advice. The motor is not a weed wacker motor. I will buy motors and parts, I just dont want to buy a finished product. One thing I dont understand is gearboxes. Do I need to get one or do I just run a chain in your gear ratio?


---------- Post added at 10:57 AM ---------- Previous post was at 10:55 AM ----------

The speed is the speed limit on all roads to school, and the wheel diameter is required by law. Otherwise I would go bigger.

---------- Post added at 10:57 AM ---------- Previous post was at 10:57 AM ----------

I dont know the motor cc

 

[Functional Artist]

Is something like a Freedom Scooter what you mean by "motorized foot scooter"?

http://www.diygokarts.com/vb/showthread.php?t=41944

This one is electric powered
...but, there is a gas version too

I picked it up on Craig's List ~$50.00
…it just needed fresh batteries

Here is more info
https://www.youtube.com/watch?v=c2UljQuFBXM

 

[mckutzy]

Depending on the motor(post some pics as to what this is, and the scooter), It may or may not have a gear box...
Or typically it needs a centrifugal clutch(It makes it an "automatic transmission") then to the final sprocket(if it doesnt need a jackshaft)...

Also depending on your state laws.. you might need to know the displacement for insurance/licensing purposes....

 

[itsid]

Well there IS NO GEARBOX you could use.. so that's out of the question.

that gear ratio I suggested ONLY works with a TC instead of a centrifugal clutch.
(series 30 TavKit from ebay)
but you'd still have a tough time.. 3hp engines usually have a 5/8" shaft..
the TC needs a 3/4" or 1" shaft to be mounted..

and you will run into numerous tiny problems alike.

So scrap the combustion engine idea and
take a BOMA 2kW electric motor instead.. that will have a much easier time doing the same and since there are plenty of scooters with that exact layount
(small wheels, 1600-2000 Watt BLDC...)
you can pick their spare parts diagram to find the proper matching parts for your build.

'sid

 

[foehammer]

Yes What I am Thinking is like the freedom scooter. The motor is a outboard boat motor. The lake I live by does not allow motorboats so I need a application. My dad told me It was 3hp but I checked, Does not say hp. I called the guy who sold it and he told me it was 5-7 hp.
Thanks itsid for the recommendation.

---------- Post added at 01:13 PM ---------- Previous post was at 01:08 PM ----------

Mcutzy the link to the state law says motorized foot scooters are bicicles so they don't need insurance.
here is the link:https://www.house.leg.state.mn.us/hrd/pubs/ss/ssmotsctr.pdf
there is nothing on the cc. I am thirteen, so I can legally ride it.

---------- Post added at 01:14 PM ---------- Previous post was at 01:13 PM ----------

I will send pictures later.

---------- Post added at 01:15 PM ---------- Previous post was at 01:14 PM ----------

The motor is rusty

 

[landuse]

Yes What I am Thinking is like the freedom scooter. The motor is a outboard boat motor. The lake I live by does not allow motorboats so I need a application. My dad told me It was 3hp but I checked, Does not say hp. I called the guy who sold it and he told me it was 5-7 hp.
Thanks itsid for the recommendation.

---------- Post added at 01:13 PM ---------- Previous post was at 01:08 PM ----------

Mcutzy the link to the state law says motorized foot scooters are bicicles so they don't need insurance.
here is the link:https://www.house.leg.state.mn.us/hrd/pubs/ss/ssmotsctr.pdf
there is nothing on the cc. I am thirteen, so I can legally ride it.

---------- Post added at 01:14 PM ---------- Previous post was at 01:13 PM ----------

I will send pictures later.

---------- Post added at 01:15 PM ---------- Previous post was at 01:14 PM ----------

The motor is rusty

If it is an outboard boat motor, it might be water cooled. That is going to be a problem unless you make it water cooled as well,

Unless you post pics of what you have, everyone is just going to speculate and not give you pointed advice. So my advice to you would be to post some pics if you want real help

 

[foehammer]

We know the motor is air cooled because we could just hook it to something and it would just turn on You could also walk with it running.

 

[Karts of Kaos]

you could make a bike that runs on pro pain or vapors.
quote( Motorized bicycles or “mopeds,” which are bicycles that also have
attached electric or liquid-fuelled motors and have a maximum speed
capability of 30 mph. These must be registered as motorized bicycles and
can be operated on either a driver’s license or a motorized bicycle permit. )quote. it says liquid

 

[foehammer]

Thanks but no license

 

[ol'joe]

LP=liquid propane

They would bust you....Joe