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An 11.4 centimetre sit bone width and choosing the right bike saddle

19/5/2023

Translation: Megan Cornish

11.4 centimetres. That’s the exact distance between my sit bones. Do you know your measurement? You should if you’re a regular cyclist.

I’ve wanted to find out mine for ages. And I want it to be as accurate as possible. Exactly how big is the gap between my sit bones, and what effect does that measurement have on choosing the right bike saddle? I have three points of contact with my bike: the pedals, the handlebars and the saddle. As far as the former goes, I found the best type for my riding style after a few attempts: Magped magnetic pedals. Next, I wanted to find my perfect saddle.

Too narrow, too wide, too soft

If a saddle’s too narrow, it pinches – right where you don’t want it to! That’s why it’s important that your sit bones lie evenly on the saddle. If a saddle’s too wide, you get chafe marks from your thighs rubbing on the sides of it. This also reduces pedalling efficiency, as the saddle impedes pedal movement. The saddle shouldn’t be too soft either. If it is, your sit bones sink to the extent that it aggravates sensitive deep tissue such as muscle and tendon insertions. After around 30 minutes, you’ll develop a dull pain that feels like pushing and pulling.

The sit bones sinking deep also puts more strain on the perineum in men and the low pubic arch in women. That’s why a soft saddle is only really suitable for short rides.

I was pretty happy with the Selle Italia Flite Boost that I’ve used for two years. But I felt the same about the old tyres on my Giant Revolt 0 until recently. Then I fitted new Schwalbe ones and now I seem to be flying over the road on my gravel bike. Not over the handlebars. And, two years ago, I was recommended SQlab products in the comments on one of my posts.

SQlab at Cycle Week

Zurich recently played host to Cycle Week, Switzerland’s largest cycling festival. My first stop was the SQlab stand, which was offering to measure my sit bones and other body parts for free via a special app. That’s where I met Beat Spörndli, who measured me from top to bottom.

Beat Spörndli from SQlab.
Source: Patrick Bardelli

To measure the gap between your sit bones, place a piece of corrugated cardboard on a chair at home, sit on it and press your buttocks down, leaving two imprints. Mark a dot in the middle of the imprints, then measure the distance between them. Job done.

Bike shops often offer this service as part of a professional bike fitting, where, like the SQlab stand at Cycle Week, everything is done with an electronic chair which measures your bottom imprint exactly. In my case, the result remains the same: 11.4 centimetres.

Measured with the special sensor chair at SQlab: 11.4 centimetres.
Source: SQlab

Measured by hand: 11.4 centimetres.
Source: Patrick Bardelli

Now for the saddle: Flite Boost or Ergowave?

So, what does that equate to in terms of saddle width? Aside from sit bone width, riding style also comes into play here. Simply put, the more athletic your stance, the closer your saddle will be to your actual sit bone width. The image above is a great illustration of this. Since I like an athletic stance, my saddle should be 1 centimetre wider. According to Beat Spörndli, a saddle between 12.5 and a maximum of 13 centimetres wide would be ideal for me. The Selle Italia Flite Boost is a lot wider at 14.5 centimetres.

As I was at the SQlab stand and I know my buttocks, I paid a bit more attention to the saddle width on every ride and noticed the extra two centimetres. Suddenly, I could feel the Flite Boost on my inner thighs with every pedal stroke. Boy could I feel it. And of course Beat Spörndli’s app churned out various product suggestions for me during my visit to his stand after the test. For example, this saddle here, which of course I absolutely have to test now. Does a few centimetres less mean a more enjoyable ride? I’ll try the Ergowave active and let you know.

Bike saddles

Sqlab 614 Ergowave Active 2.1

Header image: Patrick Bardelli

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Patrick Bardelli

Senior Editor

Patrick.Bardelli@digitecgalaxus.ch

From radio journalist to product tester and storyteller, jogger to gravel bike novice and fitness enthusiast with barbells and dumbbells. I'm excited to see where the journey'll take me next.

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