My clutchless minibike

[Cotmullion]

hi,

just a heads up. how exactly does a clutchless bike work? obviously it has some sort of device to disconnect the power

What do you mean? It has no clutch, just a sprocket welded to the engine shaft, the a chain to the rear axle. If the engine, or the axle rotates, the other will follow, hence it is push start.

 

[jr dragster T]

Why did you EVER weld the sprocket to the crankshaft? It could melt the seal on the side cover, and make it imposible to ever remove the sidecover for maintence.

 

[Russ2251]

...It has no clutch, just a sprocket welded to the engine shaft...

Direct drive need not be welded on. Just hold with set screws. Unhappy with ratio? Just change the sprocket. Click here.
See attached:

 

[Russ2251]

I would think that welding crankshaft might warp or at least remove temper of steel.

 

[Cotmullion]

I would think that welding crankshaft might warp or at least remove temper of steel.

It didn't warp the steel, and the seal seems fine.

 

[Russ2251]

And Rockwell hardness?

 

[jr dragster T]

And what about the temper of the steel? Whoops looks like me and Russ posted at the same time. You obviosly have acces to sprockets so why didnt you just buy a keyed sprocket and use a key?

 

[Cotmullion]

And what about the temper of the steel? Whoops looks like me and Russ posted at the same time. You obviosly have acces to sprockets so why didnt you just buy a keyed sprocket and use a key?

It probably makes little differance if I do now or not, seeing as I've had the welded sprocket on for a couple of months now.

 

[Cotmullion]

Here's some pictures of the minibike. I don't recall using any real motorcycle parts on it whatsoever. Since the last comment, I've replaced the engine, for exactly the same sort, and cut the woodruff key to make a keyway, so it will soon have a clutch. They don't seem to have any 3/4 inch, 41 chain clutches in the U.K, so I bought one from an American site. I've moved the fuel tank to a better height above the carb, and managed to upload pictures! I've also changed the rear wheel and axle setup so that it is more cleanly built and the wheel can be reused. I've improved the frame welds too!

 

[Cotmullion]

http://www.youtube.com/watch?v=8OMKMP0AO4o

 

[SpyGuy]

Man, that's a tall frame. Why did you make it so tall? (Not ragging on you, just asking ....)

I'd take the other engine and make a chopper frame for it .....

 

[BradenM]

Loving the dukes of hazard theme you got going on there, with the orange and the confederate flag

 

[Cotmullion]

A few, more current, minibike pictures:

 

[BradenM]

Very nice!

 

[ColokartDad]

I'm interested too, but the link didn't work for me!

Just watched the video,, gotta love this kid!!!
Hats off to ya!!

 

[TheScreamer]

Good for you... Looks like a heck of a lot of fun!

 

[tykenfitz]

Nice, simple bike! But, since you have so much extra space in there I would suggest a larger engine and a comet clutch. And engine would be really cheap on CL. Oh yea, and BRAKES!

 

[pmat]

He does have a foot brake, just gotta look a bit closer