Size matters. In fact it can make all the difference in the world.
And, believe it or not, in the case of bikes, too big is way worse than too small, and here’s why.
A bike that’s too big for you, is a bike you’ll struggle to get comfortable on.
Your speed will also be compromised.
It’s extremely difficult to get aero on a bike that’s too big for you, and when we’re talking time trial bikes, where the desired outcome is to get from point A to point B in as little time as possible, aerodynamics are of significant importance.
In 2013 at the Ironman Triathlon World Championships in Kona, Luke McKenzie and Faris Al-Sultan’s average power over the 180km cycle leg varied by just 1 watt (Luke 281 watts vs Faris 280 watts) yet Luke rode 8 mins quicker.
Both were on what I regard to be the right size bike, the time variance (in my opinion) can be attributed to their fit, their clothing, the position of their hands and they manner in which they carried their nutrition and hydration. In other words AERODYNAMICS.