Tri bikes aren’t constrained by UCI rules otherwise tt bikes would have steeper seat tube angles. Tri and tt are all about aerodynamics. Flat back is optimal but that also has to be looked at with what that does to power output of the rider. There’s a story about Cancellara being stuck in the wind tunnel and it was determined that a flat back for him cost more watts than saved by raising his bar height a couple cm. In other words he made more watts than he lost by being less aero but more powerful. UCI goals are laudable. They want the best rider to win not the best bike. But the rules make fitting a tt bike to really tall and really short riders difficult.
March 30, 2021, 9:38 p.m. - Andy Eunson
Tri bikes aren’t constrained by UCI rules otherwise tt bikes would have steeper seat tube angles. Tri and tt are all about aerodynamics. Flat back is optimal but that also has to be looked at with what that does to power output of the rider. There’s a story about Cancellara being stuck in the wind tunnel and it was determined that a flat back for him cost more watts than saved by raising his bar height a couple cm. In other words he made more watts than he lost by being less aero but more powerful. UCI goals are laudable. They want the best rider to win not the best bike. But the rules make fitting a tt bike to really tall and really short riders difficult.