Compared to a regular road bike, women’s triathlon bikes are designed with a different geometry. The seat tubes of a triathlon bike are inclined more forward with 75 to 78 degrees of inclination and are lower on the front end to provide a time trial position. Due to its steeper seat tube angle, the quadriceps are emphasized more. This spares the running muscles so you can conserve some energy for the run later on.
Ordinary road bikes on the other hand are designed to corner, climb, and sprint. Their seat tube angles range from 72 to 74 degrees and are set up to cater for common riding positions. They are more upright and less aerodynamic so they require more muscle power to move them forward.
However, if you do have a decent road bike, there is no need to panic and go out and get a new bike. You can … Read the rest