An effective set up is critical if you want to ride faster for longer
I am a self-confessed lover of the tradition in cycling, as much as it sometimes conflicts with my scientific education and approach to coaching and preparing cyclists to race faster. The ever-evolving field of sports science has challenged many of the conventions in cycling and possibly none more than the current thinking around bikefit.
When I was a lad first starting to race, most of the "fit focus" was on the knee. It was really as simple having the right amount of bend at the bottom of the pedal stroke and ensuring that the knee was directly (or very close to) above the pedal axle when at the "3 O'clock" position. Bingo! That's how you set up both your saddle height and fore / aft position. The simplicity of this model did always trouble my inquisitive mind as did the regularity with which this approach produced "shitty" looking positions for short cyclists.
Fast forward (quite) a few years and more modern thinking around bikefit has shifted to consider the hip and pelvis as the keys to having an effective position on the bike. More specifically, it is critical to have an anterior pelvic rotation in order to achieve an aerodynamic position and a flat or neutral spine. And this brings me back to short people (like me).
Set me up on a bike with traditional knee bend and KOPS (knee over pedal spindle) and it becomes almost impossible to produce an anterior pelvic tilt without causing a near-pathological impingement at the front of my hip joints. The results?
And so to crank length.
Question: Why when there is such a huge range of heights, limb lengths and flexibility ratings amoungst cyclists, are there only three (mainstream) crank lengths that vary by a total of only 5mm???!!! Answer: tradition. "Ah-Ha", I knew it, that is why tall cyclists generally find it easier to look good on a bike. Their crank lengths are a better match for their bodies.
So how short can a crank be before we lose efficiency? Well, the research so far suggests that it may need to be very short indeed. There has been a strong resistance to shorter cranks (there is that tradition thing again) based on the assumption that a shorter crank arm will reduce leverage, but almost all of the studies conducted to date refute this.
Team Sky have set the bar in terms of adoption of sports science and using it to their competitive advantage. They are also leading the way in the field of crank length, conducting extensive off-season testing using shorter than traditional cranks. Watch this space.
Here is my take on it.:
I foresee significant changes in the industry where a far greater range of crank lengths are available for riders. These will be based on science, not tradition and consider elements such as height, limb length, age, functional mobility etc.
For shorter riders (apologies for the bias) using a shorter crank, raising and shifting the saddle slightly forward may just make you look like that tall rider you have always envied.
Bottom line is: Go get a proper bikefit from a qualified, experienced professional. Go there with an open mind, trust the science and try as hard as you can to let go of tradition.
* Photo credit: "Powercrank / Dr Frank Day"