Bike Fitting Advice Needed: How Critical is Having the Kneecap Directly Above the Pedal Axle?
I have long legs and a short torso for my height - 5'11 with a 33/34" inside leg (depending on how you measure it and which brand of jeans you believe).
So for a bike to fit me well, it needs a frame that is proportionally tall when compared with it's cockpit length. Or a big stack for a given reach in bike fitting parlance. Some people would call these sportive bikes.
However, one subtlety is that much of my leg length is in my femurs (the top half). I had a professional bike fit a couple of years ago which positioned my saddle and bars nicely in relation to one another, though the bike fitter was also adamant that despite my long shanks, it was really important to still get my kneecap directly above the front pedal axle with the cranks in a horizontal position - for optimum power transfer.
I get the theory, but the result of that is:
- the saddle is positioned way back on it's rails, on a layback seatpost
- a short (90mm) stem to stop me having to stretch too far
- my centre of gravity is positioned towards the rear of the bike
- meaning I compensate by moving forwards whenever I need the front tyre to bite hard in a tight or fast turn
- meaning I can't remain seated as much as I would like on very steep climbs, and when I do get out of the saddle I occasionally bang my knees on the bar
I also feel like I'm over-using my glutes - I get a lot of muscle tightness in my hamstrings and backside that takes a lot of stretching to get rid of, whereas my quads never really feel too fatigued.
I know that it's theoretically better to use this muscle group (over the quads) primarily, because it's a much bigger/stronger group that can store more energy. But I am tempted to slide the saddle forward slightly to redress the Centre of Gravity issues, and try recruiting my quads a little more and glutes a little less.
Any experienced bike fitters out there? Do you reckon I should give it a go, or is that just a good way to decrease my power? I have a 100mm stem sat in the garage, so could easily shift the whole cockpit forward slightly in equal measure.
I run 175mm cranks, and mostly do 40-60 mile recreational rides once or twice per week, though usually tend to push myself quite hard.
All sensible advice will be greatly appreciated, especially by my aching bum cheeks!