mini chopper

well......i cant help it, the lifted one needs parts, and i aint got the money for them at the moment so ima start fab work on this, im getting a chopper bike frame from my girlfriends lil brother and im mounting either a 7 hp briggs or a 16 hp briggs twin on it, i need help figuring the gearing cause i want it to be able to cruise at about 50-55, doc sprockett, you deal with carts right, can you help me lol

Right up my alley! 55 is f'ing suicide on a minibike, though.

Meanwhile- for calc purposes, I will need the overall diameter of the rear tire. Now- does that 7hp have a 3/4" shaft, or 1"? Clutches and CVT's for a 1" shaft tend to be quite a bit more expensive than 3/4". Or, you could do a mower-type belt-tensioner clutch...

the motor has a centerfugal sprocket clutch on it already, im taking it off and rung a belt back to a jack shaft, going to run a 3"- 7" pulley, then i need help with the sprockets, im prety sure the tire is either 20 or 21"

going to pick up the bike today, will get some pics for yu guys

Excellent, can't wait to see them! Then, we can get tooth counts, pulley sizes, and everything else we'll need to figure out your gearing.

Why take the centrifugal clutch off? I would leave it unless you are going with a torque converter like Fearlesses go-kart.

Is it one of the newer Schwinn Stingrays? Those things are sweet dude, I saw a video of one on YouTube and they fit a Harbor Freight engine almost perfectly and look just like a mini chopper.

yea, i got her had to modify the frame to fit in the 7 hp, so i just went a head and stretched it a foot she is strong, no flex, and the rear tire is a 22"

Pics!

You should candy gloss the frame a bright color and re-chrome the fenders if they are all screwed.

doug, i wish it had the fenders, but im thinking bout either mattalic blue, candy apple red, or burnt orange

that is a 5HP motor not 7 he riped you off Richie. Reason I know is becasue our family has a tiller that that same motor and it says 5HP

oh, thats fine with me, i got it for free lol, but thanks for letting me know, i have to get a new carb for it

Have a look 'round the engine, there's bound to be some numbers on there somewhere- and we can put the mystery to bed. Why are you looking for a new carb? The video was a bit dark- is the carb missing? If it's there, surely you can repair it.

i didnt see a sproket on the rear tire

Look for a can of Rust Oleum (I think0 Metallic Blue. Its expensive as poopie, but my friend is using that on the inside of his 1963 F100 with some aluminum (basically silver) paint and it looks classy. If I see his truck ill try and snag a picture.

i was thinking of the orange duplicolor metalcast, and there isnt nothing wrong with the carb, its just i wantone that aint attatched to the gas tank,

this is it stretched 1 foot and lowered 2 inches

richie thomas wrote:

this is it stretched 1 foot and lowered 2 inches

Looks good.
I might built myself one

well guys, im picking up some metal tomorrow, going to start designing a custom seat pan, and gas tank, but m not sure what design i want to go with, any ideas?

one option
heres another

The second 1 would be easer to fab

true lol and i dont have the tools to do the first one

I like the angular one. Make sure its sealed good too.

yea, ill do that one, it will be easier, the whole build is like a prototype for me, im building this one for experience, then im going to build a custom frame and do a full size one powered by the 16 hp oppy, ill get the tools and do that one round , but im picking up some parts tomorrow, and i mught have a carb i can use on this motor

If the tank thats on the carb doesnt get in the way of anything, you could make your tank, and using a barb fitting tap the tank/carb and have more fuel capacity.

i had thought of doing that, however, the carb that is on it doesn't have seperate controls for the choke and throttle, so i want one that does, and i just dont want the ugly tank there lol