簡單定義: A triathlon bike is specifically designed to be ridden comfortably and efficiently in the aerodynamic position using elbow-rest style aero handlebars. Triathlon geometry bikes facilitate the transition from cycling to running better than road geometry bikes. 配備可以讓手肘依附的休息把,三鐵車的設計可以讓車手在較佳空氣力學的騎姿下更舒適、更有效率地騎乘。另外、相較於公路車、三鐵車的幾何更有利於三鐵從騎車到跑步之間的轉換。
三鐵車及公路車選購參考: - If the primary reason you are buying a bike is to participate in multisport (triathlon or duathlon) events and do solo training rides- Buy a triathlon geometry bike. - If the primary reason you are buying a bike is to participate in group rides or races, buy a standard road bike. - 主要目地是參加三鐵賽或二鐵賽,而且大都是單獨騎乘、訓練---購買三鐵車 - 主要目地是參與團體輪車競速的話--購買一般公路車 (操/制控性相對較佳)
這個順便貼一下: There is a common misconception that the seat on a triathlon bike is "farther forward". It is not. The fact is the bottom bracket is relatively farther back. This puts the rider’s feet farther back, opening up the torso/femur angle. 一般人常誤以為三鐵車的座墊位置"嚴重偏前",其實是BB相對位置更偏後側才對,藉此讓車手的勇腳能向後延伸以伸展軀幹及骨盒角度。
One difference between a time trial bicycle and a road bicycle is the use of triathlon handlebars or aerobars. The main part of the bullhorns curves forward (like a road handlebar), but where the road handle bar curves down, the time trial bar ends. This provides a low tucked position that is aerodynamic while providing good stability.
The time trial bar also uses a "clip on" bar or aerobar which attaches to the main bar near the stem and provides a position where the hands and fore-arms are close together, low and forward, providing a very aerodynamic (though less stable) position.
Time trial races tend to be much shorter than road races, so comfort is less of an issue. Also, control of the bike is less important, since there is little chance of bumping another rider and the courses tend to be less technical with little hill climbing, turns or descents.