bike

Hello,
The main difference between "road" and "tri" geometry is the SEAT TUBE ANGLE. If you step back and look at a bike, this anlge is the one made between the SEAT TUBE and the ground. A typical tri bike has a STEEPER seat tube angle, meaning the seat tube is closer to vertical (90degrees) than a road geometry. Typical "road" angle is about 72-73, while tri bikes range from 76-80.

What the steep angle does is push your position farther FORWARD towards your handlbars. This does two things :
1) helps ditribute your weight more evenly on the bike, so you can rest comfortably on the handlebars
2) allows you to use your QUADRICEP muscles more, which for many triathletes coming from a running background makes for an easier transition later on when you hop off the bike and start running.

As to your question about commuting miles....Even for a sprint tri I think you should be getting your continuous rides up to a longest one of well over an hour. There IS indeed a big benefit to doing a lot of FREQUENCY in your riding, running, and swimming, BUT athletes get a large benefit from adding a LONGER ride, run, and swim in each week. These help our bodies get better at performing when fatigued, which is a more realistic situation compared to what racing a sprint tri wuill be like.

Take Care,
Jay

Check out this post as it deals with your question somewhat:
http://www.beginnertriathlete.com/discussion/thread-view.asp?thread...

Still Tri'n
Michael