An Amusement & Diversion for The Genteel Cyclist. Daily.

Monday, March 17, 2008

Get shorty: The extreme wheelbase fad of the 70s

Today, Dave Moulton has some neat reflections on a certain mid-70s trend in bike frame design: the foreshortened wheelbase of time-trial bikes. Dave says the extreme shortening of the chainstays maybe shaved some weight from the frame, but otherwise served no useful purpose other than cultivating an industry-wide fad. But I think there is another reason, and that's the same reason people start smoking cigarettes: Because it looks cool.



Dave says that some framebuilders at the time actually tightened up the headtube angle too, thereby bringing the front wheel a bit further under the rider. Needless to say, an extremely short wheelbase like this is going to be a bit of a problematic ride -- not least because the natural flex in a fork when you're breaking hard will put rubber on your frame -- but if such a fad must sweep the peloton, then better to have it hit time trialers, who are afterall only a danger to themselves.

On the other hand, I have seen a bike with the most extreme wheelbase ever, and that would be Ines Brunn's trick fixie, where she needs to be able to turn on a pfennig.

3 comments:

Matt said...

There were Paramounts made with a curved seat tube to tighten up the rear triangle. They also did a 1974 Sprint with a bent seat tube as a production bike. See a photo at this page.

Pinchie said...

Yeah, I remember that Schwinn Sport, my pal Brion had one of those that was the envy of the 9th grade.

You see the same sort of deal on today's TT and Tri bikes -- in part to close up the airdrag between seat tube and wheel, but I have to think there's a reason why TT physiology would prefer a very small rear triangle with your butt almost directly over the axle -- and yet, you so often see those guys perched on the very rivet of the seat. Go figure.

Old Nevermore said...

Simple, really. Tight bikes look hot.

..."and style is fundamental in this category."