5cm Saddle Setback Rule

The UCI has a lot of vague rules, and a lot of rules that don’t make sense. This one is quite possibly my least favorite. The rule (1.3.013) states that the tip of the saddle shall sit 5 cm or more behind the bracket unless there is a morphological exemption. In the case of the exemption the saddle shall remain behind the bottom bracket. A morphological exemption is given if the commisaire determines that during the normal pedal stroke the knee does not pass in front of the pedal spindle.

Morphological Exemption Test

This rule affect most riders in only 1 way: TT positions. It keeps riders from riding ‘too far’ forward. However for short people it is a bit more problematic. Reasons it is dumb:

Short people need to sit farther forward than tall people on average. Short people have shorter body limbs and therefore need to sit farther forward. This rule is in NO way proportional to height. If your saddle height is 80cm, 5 cm of setback puts your effective seat tube angle at ~77 degrees. If you are short like me and run a saddle height of 65cm, your effective seat tube angle is ~73 degrees. No 73 degrees isn’t unreasonable but every person is different and every saddle is different…. which brings me to point numero 2.

Different saddles are designed for you to sit in different spots. I used to ride a specialized toupe saddle. It was pretty short and I sat pretty far forward on it. I was at just about exactly 5 cm of setback on that saddle. I’m now on a Selle SMP. The spot where I sit on this saddle is a lot further back, and it is 2cm longer. This means my saddle setback is now about 1.5cm. Same exact position on the bike, different saddle setback. In fact If I were to chop off the front 3 cm of my saddle (which I never sit on), my bike would be very close to being UCI compliant, no affect on my bike fit AT ALL. Before my saddle change I didn’t have to care at all about where my knee sat in relation to the BB. But now I do! Awesome, which brings us to point #3.

Who decided that the knee sitting behind the pedal spindle was a good fit? I’ve never heard this as advice ever, EVER. In fact conventional wisdom typically puts the knee  OVER the pedal spindle. Meaning if you followed normal wisdom and were me your bike would not be UCI compliant. That isn’t necessarily the best advice either, in fact there is absolutely no physiological relationship or requirement for knee placement with respect to the pedal spindle. None, AT ALL.

This rule blows, make a new one please UCI.