At 2/6/2008 11:05 AM -0500, John Betmanis wrote:
>I have here a 1993 Gardin poster showing four bikes with that reverse
>orientation of the s-shaped seat tube. They all look like tri bikes with
>"funny" handlebars. (Other bikes shown, including a track bike, have
>straight seat tubes.) Looks like weirdness for its own sake. Most tri folk
>were runners and swimmers and new to cycling, so they were easily sold on
>unconventional stuff they though would give them an edge. Using this
>reverse s-shaped seat tube and conventional angle lugs would be like having
>an extremely steep seat tube angle, putting the rider in an aerodynamic
>position with forearms on the aero bars.
We're getting a little OT here, but the frame is lugged steel.
I think the steep seat angles on triathlon bikes are because the running and swimming condition the glutes and hamstrings to be efficient in a different area of the range of motion of hip flexion. I've read of angles as steep as 88 degrees.
"When your only tool is a hammer, all your problems start looking like nails." The reverse curve is a simple way for someone who is only comfortable with lugged construction to accomplish the same position. There are framebuilders who have never learned to do fillets and some very experienced ones who have never done any sort of welding.
Mark Stonich;
BikeSmith Design & Fabrication
5349 Elliot Ave S. - Minneapolis. MN 55417
Ph. (612) 824-2372 http://bikesmithdesign.com
http://mnhpva.org