Thread: Bicycle Engine
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Old 07-22-2013, 02:31 AM
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silverbear silverbear is offline
The Boy Who Never Grew Up
Join Date: Jul 2009
Location: northeastern Minnesota
Posts: 8,131
Default Re: Bicycle Engine

Some years back I started this madness with a series of Tanaka Bikebug motors, friction drive with a whopping 26CC's of raw power. Ha!

Moved up to several China girls with better power and bigger problems. Then a 79cc Harbor Freight which was a step up in power and reliability.

Had an early version of the Golden Motor pancake motor (front wheel) and tried it both by itself and in combination with a China girl. Liked aspects of it, but the lead acid battery weight was a deal breaker and the electric has been sitting on a shelf. It is now off the shelf and will be part of a 63 Schwinn American Deluxe hybrid mated to a pull start china girl converted to tricycle. Battery weight will be less an issue with a trike and the batteries can be lowered to just above the rear axle. If I like it then someday it will get the newer, more efficient batteries. This will be my geezer ride when I am truly an old fart. This is a back burner build.

Three bikes are a return to 2 strokes, but not China girls. One is a vintage British made Villiars midget of 98CC's which reportedly run forever. This build is a 1934 Elgin. The slower revving engine was made for Atkins rotary mowers and I'm running it through an SBP shift kit to a three speed Sturmey Archer rear hub. Had hoped to finish it this summer, but won't. No hurry. Should be a classy, fun ride.
Another quality 2 stroke is a model 1932 Fitchell & Sachs German light motorcycle engine of 98 CC's with a built in 2 speed transmission. What can I say? German engineering and the engine was made in 1934. It's a long ways from China. The engine powers my Indian Hiawatha build which is ongoing for over three years now. The bike converts from a two wheeled light motorcycle to an early Indian inspired tri-car. Work is scheduled to resume on it in August. Don't know when it will be done, but should be on the road a year from now. Its a handsome bike.
The other 2 stroke is an American made 147CC Jacobsen with reed valve Walbro carburetor. It is to replace a 99CC Harbour Freight Predator engine on a 51 Panther build "American Flyer", the one with the modified Grumman canoe sidecar. The Predator is a fine little engine but I need more power for this heavy bike. Circus bear, dog, heavy duty bike with Suzuki fork, sidecar adds up and needs more power for hills and such. The Jacobsen is compact and appears to be very well made. We'll find out in a few weeks. It is small enough to possibly pass for 50 CC's. This is one reason for my shift back to 2 strokes... more power in a small package than a four stroke. I could never pass off a big Preddy engine or a 5 horse Briggs around here pretending it was 50CC's. I'm trying to stay under the radar, so far successfully. I want the motors to look and sound pretty innocent. If stopped with the Jacobsen and asked what displacement I will mumble the hundred and be clear in saying 47CC's. Also have another 2 stroke project which uses a 50CC Tomos moped engine in an AMF Roadmaster frame. Still need to figure out the wiring on it and lace up new wheels. This one has a two speed transmission. Back burner build.

A second 147CC Jacobsen is being readied for an upcoming build over the winter, a Whizzer inspired belt drive 51 cantilever Schwinn with in frame copper gas tank made by Tinsmith, Hercules light motorcycle fork, fatty tires and will be referred to as "kindalikeawhizzer". It should be a smooth and fast ride. I may give it to my youngest son for his 34th birthday next spring. Wanted to do something with a rear sheave and suspect this will be my last build. After that it is finishing up the other ones and doing make-overs of what I have when I get the urge to tinker.

That's enough motorbikes. This is crazy. But its been fun!
Someday when I grow up I will probably lose interest in toys with wheels, but until then...
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