Bike Saddle Fit Case Study : Right saddle/wrong position

The two pressure maps pictured here are for the same rider and the same saddle. He had two bike fits prior to coming to Velocity, and he was still suffering from saddle sores. By moving his saddle down 0.5 cm and forward 1.5 cm, we transformed his pressure map and riding experience.

 

Bike Fitting, Saddle Fitting, Bike Fit, Saddle Fit
Same saddle, New position

  • Firstly, the table at the bottom of the picture shows how the pressure before was extremely high on the Left Rear of the saddle and the right Nose. The changes resulted in 32 – 45% reductions in the peak and mean pressures in these areas. The Right Rear pressure stayed where it was. The result is a balance of pressure that should be comfortable and should eliminate the recurring saddle sore on the right nose of the saddle.
  • The thin black “squiggly” line is the trace of the centre of pressure as the rider pedals.  On the before (top) picture, it is moving wildly. There is no consistency, and it is moving front to back as well as side to side. On group rides, it was pointed out to him that he was rocking, but his previous bike fit put him there, and he believed “a higher saddle means more power in my pedal stroke”.  In the after (bottom) picture, it centre of pressure traces a much, much tighter and more consistent path.
  • The horizontal red line is the regression analysis (best fit line) of the centre of pressure as the rider pedals. On the before picture, the line is very wide, and it is offset to the right. The after picture shows a much shorter line (less rocking), and it’s much more centred (better balanced).

It’s critical to highlight that these improvements were achieved by changing the position of the saddle, not by changing the actual saddle itself. While the “Before” position on the bike resulted in body angles that were within the standard “fit window”, the rider achieved those angles by sitting on the wrong part of the saddle!

The rider’s new position on the bike still matches what is expected, but he now has a stable base for his pedal stroke that eliminated rocking and saddle sores.

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