Pocket bike powered bicycle

[newfiecart]

Hey guys, I've posted pics of this bike quite a while back with a whipper snipper motor mocked up, but I've finally moved forward ever so slightly with this project.
I made up a motor mount which still needs to be welded in, and a cardboard gas tank mock-up. I will probably use aluminum for the tank, if I end up doing it. Otherwise I might try to find some other pre made tank, which I don't think would look as good..
I am also trying to figure out the jackshaft. One end is going to be a 60 tooth pocket bike sprocket, and the other end will be a 17 tooth bicycle sprocket going to a 45 tooth on the wheel, which (I think) will give me around 40-45km/h.
Any Ideas of what I can do for foot pegs?

 

[Bando]

I think that it is a very small engine for your bike but should move. Regarding the gas tank, the size of it makes the engine look rather small. This gas tank would look better with a bigger engine besides being very large in capacity (about 3 gallons) for a 49CC engine. I would use a motorized bicycle fuel gas tank.

 

[newfiecart]

Now that I look at the pics, the tank does seem pretty big.. Maybe i'll make one that fits between the upper tube and the Middle ones just above the engine.
I'm not expecting a bunch of power from that engine, but it should be OK.. I can always change the gearing if need be, or get a higher performance pocket bike engine later on..

 

[Bando]

I build a 12" bike with the same engine about one month ago. A little slow but runs well. You can see it here as "mini bike".

 

[OzFab]

OH WOW! I had a bike very similar to that many years ago that had 5' forks on it...

IMHO, 40kmh is a bit of a stretch. Ask yourself "how fast does the original bike go?" The more you gear towards high speed, the more you gear away from low end torque/ acceleration

 

[newfiecart]

Wow! that's quite the front forks! And you're right.. 40km/h is a bit of a stretch.. I think the engine should be suffecient for this bike, it is a pretty small bike to begin with, and I am only 170 lbs. I just want to get it all together and do some tweaking as I go. Thanks for the advice so far!

 

[newfiecart]

I am away at work right now, but I think when I get home, I might attempt a smaller tank mock up, something similar to this:

to fit here: (see pic on bottom)

That was originally my plan from the beginning, but It seemed too small. I guess it is only a small engine that dosen't use that much gas..

 

[robbie]

If you need pocket bike sprockets, I have a couple of them. #25 chain, I think they're 60 tooth.

 

[newfiecart]

Well I just got home and thought I'd redo the gas tank.. I think this looks much better, and will be a lot easier to make..