Mid-Life Cycling

Mid-Life Cycling

23 February 2016

The Gear Maker

During the 1970's Bike Boom, millions of Americans bought ten-speed bikes.  Many people rode them only a few times, or once.  Some didn't like the dropped handlebars or small "hard" seats; others couldn't quite get the hang of shifting derailleurs.  Given the fragile nature of most derailleurs of the time, the results weren't pretty, especially when the derailleurs were out of adjustment or the rider tried to shift while standing still or under pressure.

Then there were the engineering types and tinkerers who look at any mechanical device and think "There must be a better way."  And, finally, there were lots of newly-minted lawyers with too much time on their hands who saw all sorts of potential lawsuits lurking. (Some of them helped to found the CPSC.)

One of the best-remembered attempts to correct the "deficiencies" of derailleur gearing was Shimano's Front Freewheeling system.  Basically, it incorporated a freewheel-like mechanism between the chainrings and crank so that the chainrings spun as long as the wheels were spinning. This allowed riders to shift without pedaling. 

Some people who were accustomed to internally-geared hubs (like Sturmey-Archer three-speeds) liked this new innovation, which is probably the reason why it developed something of a following in Germany, where many people still cycled for transportation but few were accustomed to derailleurs.  However, the FF system was heavy and complicated, and was equipped only on entry-level bikes.

Another attempt to bypass the idiosyncrasies of derailleurs and multiple rear sprockets is all but forgotten today.  But it was interesting in its own way.

Before its foray into the bicycle business, Tokheim had about seven decades' worth of experience in manufacturing fuel dispensers and pumps, and equipment for payment terminals and retail automation systems.  So, if you've ever owned or managed a gas station, you've seen or used Tokheim equipment.

Like a few other American companies, Tokheim thought the Bike Boom was an opening for a new profitable market.  And, like those other companies (including, of all companies, Beatrice Foods!), they thought they could make bike parts and accessories even though they had absolutely no experience with them--or, it could seem, cycling. 

Then again, Tokheim's experience with pumps and other kinds of machinery had, it would seem, at least some applicability to designing and manufacturing a bicycle gearing system.  It was at least somewhat in evidence in their "Gear Maker" system.

The Tokheim Gear Maker


When drivetrains with derailleurs are shifted to their extreme positions (small chainring with the smallest rear cog or largest chainring with largest rear cog), severe chainline angles can result.  This usually results in noisier running; in worse cases, it leads to premature chain and cog wear.  In the worst cases (especially with an inexperienced and unskilled rider), the chain can be thrown off the cogs and into the wheels or get stuck between the chainrings and chainstay.

Most cyclists learned, in time, not to shift into the extreme gear positions--or to do so carefully.  However, some could never get past that first experience of a missed shift.  Or, if they had no previous experience with multi-cog systems, they were intimidated.




That is the "need" the Tokheim system was intended to meet.  Imagine an old-fashioned Ferris wheel:  the kind with a "spider" that rotates around an axle at its center and "cars" or "gondolas" at the end of each arm.  Those cars and arms are in fixed positions and will always reach the same height at the peak of their rotation. 


Now imagine that between those arms, there are other arms, except that these arms are expandable and retractable.  Thus, the Ferris wheel operator could expand the diameter (and height) of the wheel for more adventurous customers.  But the cars of those expanded and contracted cars would rotate in the same plane as the cars on arms with fixed lengths.


 




The gear in the "gear maker" was like that Ferris wheel.  It was operated with a twist-grip shifter.  When the shifter was in its "high" position (slackened cable), the chain ran on the smallest gear, which was fixed to the axle.  Shifting down made an interposer arm push a series of bars out successively.  At the end of each bar were teeth like those of a typical rear sprocket.  The chain ran on a larger sprocket something like the "skip tooth" cogs found on some 1970s freewheels.  A tensioner--basically a derailleur cage and pulleys--took up chain slack.

For a time, the Tokheim system came as standard equipment on a few Huffy and Murray bikes.  I never saw a bicycle sold in a bike shop that was equipped with the Tokheim system, and I don't know whether anyone ever retrofitted it to a bike.  For that matter, I didn't know anyone who rode it, and only got to work on a couple of them, so I don't know how they performed in the "real world".  However, as the gears were made of plastic, I suspect they wore fairly quickly.  And, as Tokheim stopped making it around 1980 and, to my knowledge, never offered replacement parts (and because most of the bikes that came with them have long since ended up in landfills), I don't suspect that very many Tokheim Gear Makers are in use today.  But, I think, they are interesting nonetheless.

8 comments:

  1. I took up cycling in the 70s but never saw such an odd contraption. You're correct, some derailleurs of that era were pretty poor. I remember my brother's Schwinn Varsity was especially hard to shift, and I just assumed all bikes were like that. But I was amazed at the shifting performance of my first 10-speed, a Motobecane Mirage, despite the Simplex derailleurs which broke after the bike was a year or two old.

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    1. MT--The Varsity at that time came with a rebadged Huret Allvit derailleur, which had a very high operating tension. I saw more than a few Varsities and other Allvit-equipped bikes on which the cables snapped when the rider shifted.

      After the Allvit, a plastic Simplex seemed like the bee's knees--until, of course, you tried a SunTour or even a Shimano.

      Ahh..the memories! ;-)

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  2. Thanks for the post. Im a big fan of the blog, i've even put a little bookmark right on the tool bar of my Firefox you'll be happy to find out!
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  3. It's a shame there was so much junk slapped on low to middle end bikes during the boom. I remember trying to make things work as a young lad during the tail end of this period. Other than big box bikes, the quality of parts today is amazing- even at the entry level.
    Never came across this derailleur. Interesting...but hideous looking!

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    1. Chris--You're right. There was a lot of junk on those bikes. In fact, some of the bikes themselves were junk. I think one reason why we saw all of that subpar stuff is that when the Bike Boom hit, manufacturers weren't ready to keep up with the demand. So they cranked out a lot of shoddy stuff, and importers and distributors bought bikes and parts from manufacturers they wouldn't have gone anywhere near otherwise.

      The Tokheim is indeed hideous looking.

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  4. I almost included the Tokheim device when I wrote about expanding chainring cranks - being that the basic concept is a similar one. I ended up leaving it off the list though, figuring it might be worthy of an article by itself (which clearly, it is!). I didn't realize the background on Tokheim, though. I knew I'd seen the name before -- probably a bunch of times -- but could not for the life of me think where. But you're right - it was gas pumps - and scales, too, I believe.

    I've never seen the gear maker up close - but with all its stamped steel and plastic, I cannot imagine it was very reliable long term

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  5. Brooks--Isn't it funny that I was thinking of your article about expanding chainring cranks as I wrote about the Tokheim Gear Maker?

    The Tokheim is interesting in its own way. The idea of a variable-diameter chainring or sprocket is one that seems to be revived in some form or another every generation or so. There may well be some validity to it, but until it can be made reliable and (at least relatively) lightweight and simple, I don't think it will displace multiple chainrings and sprockets with derailleurs.

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