11 January 2017

Shorter And Shorter, A Century Apart

The other day, and in a few previous posts, I mentioned the Rigi frame.  It had twin vertical seat stays, like the twin laterals found on the "top tubes" of many classic mixte bikes (and Vera, my green Mercian mixte).  The rear wheel actually ran between those tubes.

The reason for it was to shorten the bike's chainstays and, therefore, wheelbase.  Shorter wheelbases make for quicker acceleration and response, all other things being equal.  Rigi was probably one of the more extreme results of a race, which ran its course during the late 1970s and early 1980s, to create bikes with the shortest possible wheelbases.

That trend resulted in other permutations of bike design, like curved seat tubes.  It seemed to run again, if briefly and less widespread, just before the turn of this century, when KHS and other companies made bikes (mainly track and fixed-gear) with curved seat tubes.

Like other fads, it's not new.  Within a few years of the invention of the "safety" bicycles, designers and builders had essentially figured out what we now know about bicycle geometry.  For the most part, bikes had longer wheelbases and shallower angles than the ones on current bikes because road conditions were worse (when, indeed, there were roads!). Also, few cyclists owned (or even had access) to more than one bike, so their steeds had to be more versatile.  And, I would imagine, the materials available then weren't as strong as what we have now (most bikes were still made of iron or mild steel) and could not withstand the pounding a shorter wheelbase and shallower angles--which absorb less shock than longer wheelbases and shallower angles--would deliver.

Still, there were apparent attempts to make bikes with shorter wheelbases at the turn from the 19th to the 20th Century. (I can still remember when "the turn of the century" meant the period from about 1890 until World War I!)  This one looks particularly interesting:




If you sneeze on this 1890s "Bronco" bike, you just might go backwards!  All right, I'm exaggerating, just a little.  What I find intriguing--almost astounding, really--is that the auction house selling the bike listed it as a "cross" bike.  Did they mean "cyclo-cross"?  If they did, I wonder whether the bike was intended as such when it was made--and, presumably ridden.

The auction house also says the bike has an "axle driven crank".  Today, we call that "fixed gear":  The wheel and pedals cannot turn independently of each other.  High-wheel or "penny farthing" bikes had such a system--on the front wheel.  

That is the reason why those bikes had such large front wheels:  To get what most of us, today, would consider to be a normal riding gear--let alone anything high enough to allow for any speed--a front wheel of at least 1.5 meters (60 inches) in diameter was necessary.

Hmm...That means the gear on the Bronco must be pretty low!

Low gear and short wheelbase:  Could this be a bike intended for uphill time trials?

4 comments:

  1. Crank driven axle? Lot of tin at that rear end as if hiding some devious gearing...

    Frame makers love to make clearances too small, should have know that was what the twin tubes were for. Dreaming of something more relaxed and with longer rear stays, I am a generation out of step as usual.

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  2. i wonder how exactly one was supposed to pedal that bike whilst sitting in the saddle since the pedals line up well behind the seat.

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  3. The Bronco looks like a unicycle with an unnecessary front wheel grafted on. Since a unicycle steers with body english you could hacksaw off everything on the forward end and still do quite well on the beastie. A lot of machines from that ere were literally made from plumbing pipe so cutting off the front end would probably save 30 pounds and then you would also have a spare tire. Win Win!

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  4. Coline--Can you imagine riding that thing in snow?

    Mike--Hmm...Maybe they had some different ideas about fitting the rider to the bike in those days. ;-)

    Phillip--Maybe the front wheel was a "training wheel", if you will, for aspiring unicyclists. ;-)

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