History of split seat tube?

To the group historians,

Who's the first to record a split seat tube that allows the rider to
nudge the rear wheel in between to reduce the wheelbase?

Scott Gordo wrote:

To the group historians,

Who's the first to record a split seat tube that allows the rider to
nudge the rear wheel in between to reduce the wheelbase?

Why do that in the first place. What is believed to be the advantage
of putting the rear axle nearly under the saddle.

Jobst Brandt

wrote: Why do that in the first place.
What is believed to be the advantage
of putting the rear axle nearly under the saddle.
^^^^^^^^^^^^^^^^^^
There might be an advantage on a trials bike, where a short wheel base would
contribute to maneuverability. The strong rearward weight bias would make
it easy to loft the front wheel for climbing obstacles. Hill climbing would
be tricky, though.

On 16 Jan 2009 17:38:01 GMT, wrote:

Scott Gordo wrote:

To the group historians,

Who's the first to record a split seat tube that allows the rider to
nudge the rear wheel in between to reduce the wheelbase?

Why do that in the first place. What is believed to be the advantage
of putting the rear axle nearly under the saddle.

Jobst Brandt

Dear Scott & Jobst,

The British went wild over short-wheelbase designs in the 1930s.

Short-wheelbase fanatics had several theories, mostly to do with
imaginary power increases.

This site has lots of examples of weird frames intended to tuck the
rear wheel as close to the crank as possible:
http://www.classicrendezvous.com/Bri...es/British.htm

Some freakish examples of short-wheelbase:

http://www.classicrendezvous.com/Bri...t_cat_page.htm
http://www.classicrendezvous.com/Bri...ard_Cygnus.htm
http://www.classicrendezvous.com/Bri...es/Grandex.htm
http://www.classicrendezvous.com/Bri..._green_pic.htm

Some split seat-tubes:

http://www.classicrendezvous.com/Bri...roberts_TT.htm
http://www.classicrendezvous.com/Bri...xon_twin_t.htm

The "Curved Tube" section makes a passing reference to the alleged
hill-climbing advantages of the short-wheelbase:

http://www.classicrendezvous.com/Bri...ylor_62Art.htm

The "Curved Tube" frame itself:

http://www.classicrendezvous.com/Bri...Taylor_JGs.htm

A desperate attempt to find something besides wishful thinking and
marketing in the short-wheelbase fad:

http://www.classicrendezvous.com/Eve...lbase_1939.pdf

An example of how British frame-building became hopelessly confused:
http://www.classicrendezvous.com/Bri...et_SL_1951.htm

Pay particular attention to the bottom bracket in that gallery:

http://www.classicrendezvous.com/ima...et_SL_51_5.jpg

The frame members projecting below the bottom bracket may have been
useful as a plough--note how the chainstays are used to form a
convenient attachment point for ropes leading to an ox-team in front
of the bicycle.

However, weird frames were commonplace in early dwarf safeties in the
1890s.

Here's a nicely curved seat-tube:

http://www.auctionflex.com/showlot.a...ction=&lang=En
or http://tinyurl.com/58wqk2

An 1887 example of _no_ seat-tube and the original floating-crank
design taken from the tricycles, in which the crank (not the rear
axle) was moved back and forth to tighten the chain:

http://www.auctionflex.com/showlot.a...ction=&lang=En
or http://tinyurl.com/6o773e

Another early no-seat-tube design that lets the crank cuddle the rear
ti

http://www.auctionflex.com/showlot.a...ction=&lang=En
or http://tinyurl.com/6l5jdn

Curved seat-tube:
http://www.copakeauction.com/bicycles/1999-post/57.jpg

A really nice split seat-tube 1889 Sparkbrook:

http://www.auctionflex.com/showlot.a...ction=&lang=En
or http://tinyurl.com/66s4gy

Best view of that split seat-tube:

http://www.auctionflex.com/auctionim..._2BX0U1NOW.jpg

As that photo shows, the early split seat-tubes were really intended
to brace the primitive cranks. Our great grandfathers used longer
wheelbases (not shorter) to smooth out the terrible roads.

Cheers,

Carl Fogel

On Jan 16, 9:38*am, wrote:
Scott Gordo wrote:
To the group historians,
Who's the first to record a split seat tube that allows the rider to
nudge the rear wheel in between to reduce the wheelbase?

Why do that in the first place. *What is believed to be the advantage
of putting the rear axle nearly under the saddle.

Should be an advantage for team time trials by allowing for more
efficient drafting. But in road racing it would seem to give a slight
drafting advantage to your opponents since they could get closer
behind you than vice versa.

On Fri, 16 Jan 2009 11:20:25 -0800 (PST), Peter Rathmann wrote:

On Jan 16, 9:38*am, wrote:
Scott Gordo wrote:
To the group historians,
Who's the first to record a split seat tube that allows the rider to
nudge the rear wheel in between to reduce the wheelbase?

Why do that in the first place. *What is believed to be the advantage
of putting the rear axle nearly under the saddle.

Should be an advantage for team time trials by allowing for more
efficient drafting. But in road racing it would seem to give a slight
drafting advantage to your opponents since they could get closer
behind you than vice versa.

Better to have a small flanged roller on a frame extension rearward from
the seatstays - to let the following rider get *really* close without the
risk of touching the leading rider's wheel.

You missed this one
http://www.mrdoo.co.uk/bigminibike.jpg

--
Michael Press