Bike Fit Baloney

Having been a multisport coach for almost 10 years I have extensively studied the issue of bike fit. I went so far as to travel to Slowtwitch to complete a FIST-certification, the leading certification in triathlon bike fit. Dozens of bike fits later I still hear the same thing.

Me: "How did the person who sold you this bike set you up on it?"

Athlete: "He dropped a plumb line from my knee down the the pedal and moved the seat back."

I then know the bike fitter is a road racer, not a triathlete. My work is cut out for me. In nearly every single tri bike fit I have ever done, I have adjusted the saddle fore-aft, and never once have I moved the seat aft. In triathlon, the name of the game is to get forward so you can get low on the aerobars, without excessively crimping yourself at the hips. That would lose you power.

It is simply unneccessary to use knee over pedal spindle. The reason for this is because in a proper triathlon set-up, you are actually applying pressure to the pedals in a rearward vector. You are not pushing the pedals down, you are pushing back.


Photo: Road bike, body upright, knee over pedal spindle intact.

There are a lot of bike shops and a lot of bike fitters who attempt tri bike fittings using their paradigm of road bike fitting. Hello, Serotta? What works for road bikes, or even mountain bikes, is a different scenario when you are setting up a tri bike.

Okay, I will confess, the picture above is of some poor dumpy guy who I found with a a google image search. But it illustrates the point well...imagine that bike with a pair of clip on aerobars, trying to fold his belly against his thighs and race a triathlon. Ouch.


Photo: Craig Alexander, riding off the tip the saddle on his Orbea Orca. Note the knee out over the toe.

Okay it's an unfair fight, but I thought, "Who could demonstrate the knee past the pedal spindle? Last years Kona champion." One more google image search, and I my prediction was correct.

With all the bike fits I have done, all the changes I have made to my own bike, all the info I have read, all point to one thing...move that saddle forward. Move it to the end of the rails, and ride on the nose. See how far Craig Alexander is on the nose of his saddle?

As Dan Empfield, the inventor of the tri bike geometry, the triathlon wetsuit, Quintana Roo, and Slowtwitch put it, "Knee over pedal spindle has nothing to do with tri bike fitting."

Take Home Messages:
1) Conventional triathlon thinking is that a forward seat angle (78-80+%) is proper. This will most likely put your knee past the pedal spindle and out over your toes.

2) Buy a tri bike that actually has tri bike geometry: QR, Felt, Cervelo.

3) If your bike fitter pulls out a plumb line to test knee-over-pedal-spindle, don't buy the bike. If your bike fitter is trying to do a triathlon fitting using road bike concepts, it will not be optimal. Triathlon specific saddles are beneficial, as are steep-angled triathlon geometry. Don't let a bike person convince you otherwise. The main symptom is that your hip angle will be too closed, and your shoulders will be too stretched out.

4) If you add clip-ons to your road bike, move the saddle 1-2cm forward. You may need to buy a "forward" seatpost. Be aware that this will affect the handling of your road bike. A tri bike incorporates the steeper geometry with better handling.


When bad things happen to a good tri bike.