Insanity On Wheels
How to exploit a gas shortage and bike boom: sell an outboard motor for bicycles. The crazy story of the Tanaka Bike Bug.
In the late 1960s, cycling began to make a come back in the U.S. The adult market for bicycles had died so completely after WWII that most companies didn't even bother offering full-sized, adult models. Even Columbia, America's oldest bicycle company finally gave up in the mid 1950s after years of advertising the hell out of bicycles. But growing traffic, pollution, and awareness about the importance of exercise began to revive the market in the late 1960s. Suddenly, health nuts, tree huggers, and disgruntled downtown penny pinchers who'd not be caught dead paying for street parking found the bicycle and brought it back from the very brink of oblivion. But the real explosion in bike sales would be triggered by what was coming right around the corner: the 1973 oil crisis.
When the oil crisis hit the U.S., not only did sales of compacts and imports soar - the bike boom reached peak bicycle. Factories couldn't keep up with demand. They began to slop them out as fast as possible, people didn't care. Bikes were big. Bikes were bigger than ever. Everybody wanted a bike. But not everybody wanted to pedal a bike. The concept of putting effort into moving your own ass around was foreign to many Americans by this point in history, long forgotten by many baby-boomers. If only there were something that could move the bicycle along, without one having to pedal... a Japanese company that specialized in outboard motors had just the answer for lazy Americans.
Enter the Tanaka Kogyo Company’s Tas Spitz bicycle motor (also sold as the Tanaka Bike Bug). Available in 1.2 or 0.8 horsepower variants. This tiny 23cc 2-stroke motor bolted to the front fork of a standard bicycle and drove the front wheel by means of a rubber roller. If everything was perfectly in tune, the planets aligned, and God himself was smiling upon you - you could get as much as 300mpg out of this thing! Understandably, OPEC was very concerned about this technological development. Or not. Because a bicycle with a 23cc motor mounted on the front wheel is not very practical, or comfortable, or safe. But it is a lot of fun.
I bought this motor with the intent of mounting it on an old tandem bicycle, but I wanted to fit it to another bike just to see what was working and what was broken. Good compression, good spark, - stuck throttle. I’ll have to pull the carb apart and see if I can locate a replacement throttle cable. On the bike, the engine doesn’t inspire confidence. It weighs 11 pounds and its right out in front of you. It feels shaky and the extra mass on the forks gives the steering a rubbery, dull feeling. Plus if the throttle worked, the coaster brake on this bike would be powerless to stop the thing. I have to wonder how many people met their ends on motor equipped bicycles in the 1970s.
Rudimentary controls: a drive engagement lever, a kill switch, and an outboard motor style throttle lever.
Here’s the cockpit view. On the right handlebar, a throttle lever and a kill button. Below them, jutting out from the motor is the “raising lever” which is used to engage or disengage the drive roller from the wheel. There is no clutch besides this thing, and it’s at about knee level when you’re sitting on the bike; Engaging the drive while the bike is in motion (and it has to be in motion) makes dealing with an old motorcycle “suicide shifter” seem like child’s play by comparison. When you come to a stop you must either disengage the drive with the raising lever, or you use the kill button.
The oddest thing about it is despite how crude it is in operation, the mechanism itself is needlessly complicated. Tanaka developed these bike motors out of a miniature trolling motor. The prop shaft and housing was cut down and the propeller was replaced with a rubber roller. Additionally the engine uses a diaphragm fuel pump operated by crankcase pressure. All this makes for a fairly heavy unit, about 11 to 13 pounds hanging onto the front fork. The advertising claim was that one could choose to pedal or use the motor, but with an extra 13lbs. tagging around for every ride, the obvious choice was to motor everywhere.
What happened to the Tas Spitz bike motors? By the late 1970s the moped boom had started. You could buy a moped for barely more than the cost of a bicycle and motor, and you got an assembled machine that was faster, quieter, more comfortable and safer. Tanaka is still around, but the bike motors have long since ceased production.
The Bike Bug's outboard motor ancestry is most clearly evident from this angle.