New member here in Northern California

[PeterJayPriest]

Hi everyone...

I've been reading posts from your site for a few months, and have now begun a project and thought it time to join.

I've thought about motorized bicycles for many years. My father took me to an automotive museum (back in the late 1960's I guess) where he pointed out a motorized wheel that was designed to be bolted to a bicycle. I thought that was a nifty idea. And I've always loved most things motorized.

But what got me going on my project, was a ride around the block on a new tandem bike I bought for my wife and I. We're getting out of shape, and I thought a tandem might get us moving...together. But the bike just sits in the garage.

I've noticed these 4 cycle string trimmers coming down in price- I have owned one for a while, and converted it to use propane almost immediately after getting it home. So....

My plan is to add a small 4 cycle trimmer engine, powered by propane, to the back of the tandem.

I'll post some pictures as progress is made.

Peter

 

[PeterJayPriest]

4 cycle tandem bike - finished! Propane powered.

I thought this would be a weekend project. It took a bit longer....

In any case, I took a few rides on my motorized tandem, and am reasonably happy with the results.

The bike is a Tandemania, now powered by either legs, or engine, or both. The engine is a Subaru Robin 35cc. I converted the engine to run on propane, and refill the small propane canisters as necessary. I've not put on enough miles to determine what kind of MPG I'm getting, but I think it's pretty good.

The gearing is reasonable, with surprisingly brisk acceleration and a fair top end of about 23 mph. The engine was fitted with a 3:1 reduction drive (off eBay for around $40.) The final ratio would still be too high, so I put in a jack shaft (made from a mountain rear bike hub) and affixed a couple of sprockets- a small drive sprocket on the Shimano freehub, 12 tooth, and a larger (55? tooth) sprocket on the driven side. The small sprocket then powers the large sprocket mounted to the disk brake flange of the rear wheel.

I'll get some pictures posted if there's any interest...

Peter