About four years ago, I bought a dozen broken pocketbikes for between $40-$45 each...
I wanted the wheelsets to make custom minibikes...
You've probably seen these types of wheels...cast alloy, 8" or 9" diameter with a street-type tire and a somewhat functional mechanical disc brake...
These wheels were designed to be used with 49cc engines, so they have bicycle chain pitch sprockets held on with three wimpy little screws roughly 1/4" dia...
An engine in the 5-6.5hp range has no trouble shearing off these screws if you get a little wild with them...
I've made some 35 pitch sprockets that mount with the three little screws and they're fine if they're not over-stressed...
But, I'm still going to make a few sprocket flange/drive hub assemblies that fit over the wheel hub and use it's triangular shape to drive the wheel...
A flange with multiple sprocket bolt patterns drilled through would allow mounting of any size/pitch sprocket...
The three little screws would only have to hold the drive hub onto the wheel and wouldn't be subject to any driving torque...
I'll post some pics after I make the piece...I'd like to put my Tecumseh HM100 Star engine into a smallish frame and smoke a few of those pocketbike tires.
...and I've started final assembly on the 'Bumble Bee'...
