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Day: December 26, 2009

Measuring My Sit Bone Spacing

 

 

 

 

Using a spare aluminum plate, some leftover cheap cardboard, a chair, and a ruler I was able to measure my sit bone spacing. This was done by sitting on the assembly with my legs bike pedal spacing apart, then grabbing the metal plate and pulling it against myself to ensure good dent formation in the cardboard. I then looked and felt for the dents in the cardboard, marked the centers with dots, and measured. I then rotated the cardboard and repeated the process to get a second measurement. Both measurements were ~122mm, so I’m happy with the result.

Some research into how sit bone measurement should translate to saddle size uncovered the Specailized Body Geometry recommendations for saddle widths, which are supposedly as follows:

· 130mm saddle for sitbone center to center width of 100mm or less.
· 143mm saddle for sitbone center to center width of 100mm to 130mm.
· 155mm saddle for sitbone center to center width of 130mm or more.

The WTB Rocket V saddle which came with my new bike (post forthcoming once it is complete) felt a bit narrow in the few test rides I’ve taken, and at ~130mm measured width these measurements confirm that it likely is the wrong size for me. The Specialized OEM saddle that came on my old bike is ~140mm and matches the aforementioned recommendations. As it has been comfortable for two years now, I think I’ll be looking at a new saddle somewhat along these lines.

Now to figure out which one to try…

† Former Power Mac G5 and Mac Pro stand.
Twelve South BackPack box.

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