Bike Fit, the P3

To get the most out of your bike, you need to be comfortable and in the correct position for efficient peddling

You don’t want to waste those valuable watts do you!

A bike fit is needed

I set my P3 to roughly same setup as my Boardman, but these are very different frame geometries, so it just wasn’t right.

The steering felt twitchy! I wasn’t comfortable at all and the whole thing just didn’t seem to work.

So off to Dynamic Rides who use the Rutul system, to get the bike set up properly.

It was really interesting. My bike was set up on a turbo trainer with a power meter and I was covered in little sensors.

We did a few runs to find out what was wrong, then started to tweak my bike to fix those issues.

All of those sensors on my body produce a 3D stick man that can be analysed and compared against a theoretically perfect position, all the time, checking the output on the power meter.

The first thing noted was that I was sitting too far back, this was arching my back too much and bringing my elbows too far back on the aero bars. This is the reason why the steering felt so twitchy! My shoulders were too far back from the centreline of the rotation axis of my steer tube, so I was twisting my whole body to steer from the hips, not rotating my spine thus keeping my torso in the same position.

The saddle was moved forward a tiny amount and wham! sorted! its amazing that tiny changes make such a difference.

But, there was still something wrong, it was comfortable now, but my foot position was not optimal and I was over stretching and pointing my toes down too much, so I was loosing power on the bottom of the stoke.

The saddle was changed again, this time lowering it to bring my foot angle back in line. It still wasn’t quite right though. To compensate for having the saddle too high, I had wrongly moved my cleats too far forward on my shoes. These were positioned correctly and job done!

Next up was to take some accurate measurements of all of the key features (see reports below) This was done with a hand held CMM (coordinate measuring machine) to give an accurate 3D measurement of the bike.

The bike feels much much better to ride, its comfortable, controllable and it feels great putting the power down.

If you buy a new bike, get it set up properly, don’t assume you can transfer the setup from another bike, especially if going from a road bike to a TT bike. The frame geometry is so different that the setup doesn’t translate between bikes.

I’m pleased with the results and I understand a little bit more about my bike now and the importance of the design (well done cervelo)

The results: -

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Anthony TowersComment