Sit bone width

[Deanna]

My pilates instructor has given me two methods, they work for my body.

Standing method (if you have very long feet or flexible hip sockets, this may not work, most of us are proportional though)
1. Stand with your feet together.
2. Keeping your ankles together, point your toes away from your ankle (so your feet are in a V)
3. Align your ankles with your toes. Your heels should be about sits bone width apart.

Sitting:
Sit down on the ground and kind-of pull your buttock flesh (sorry, cant't think of a more technical term) out from under you. You'll feel your sits bones a lot easier this way.

[batsheva]

dont think i really sit back on my underneath 'sit bones'-- (ischial tuberosities)-- i think i sit with much more weight fwd onto pubic symphysis and kind of form a triangle of weight bearing like that, with less on the 'sit bones'-- it works for me anyway :-)

[GLC1968]

I did the 'butt-o-meter' thing at my LBS but I didn't buy it. It said that my sit bones and my husbands sit bones were the same distance apart.

I came home and tried measuring them myself. I sat on the floor and grabbed a fabric tape measure. I held it between my fore fingers and thumb with about 5 inches between my hands. I rolled onto my back, flipped my legs up over my head (ie. held them up in the air towards my head), and then felt around on my butt until I found the bones on both sides. I positioned the tape measure at the bones and held on to it. I put my legs through my arms still holding on to the tape measure and voila! I had the distance between my sitbones.

(I was not nearly as contorted as this description makes it sound. )

Sure enough, DH and I do have the same width between our sitbones. Who would have thunk it...me with my big butt and him with his 'no butt'!

[emily_in_nc]

Standing method (if you have very long feet or flexible hip sockets, this may not work, most of us are proportional though)
1. Stand with your feet together.
2. Keeping your ankles together, point your toes away from your ankle (so your feet are in a V)
3. Align your ankles with your toes. Your heels should be about sits bone width apart.

Uhhhh, no. My sitbones are not 10" apart!

I have size 7 feet. I can turn my toes out a long way, though. And I never even did ballet!

[Deanna]

Hence the disclaimer about flexibility!!

[Look]

This may be a stupid question, but if you are contorting yourself to measure your sitbones, aren't they moving into a different position? Or is that only in childbirth?

Second, if one knows one's sit bone width, what does one do with that information? Isn't there still some personal preference as to how your newly mapped sit bones contact the seat? It's not like a shoe where the high point of the arch lines up with the high point of the arch support. Or is it?

I found a saddle I really liked on my third try. And the method was all art no science. On the first two I was pretty conscious of what hurt and why and then I just let my head picture what my butt would like to be sitting on. Browsing in the LBS, I just recognized the contours I pictured, bought it and it's been great. A woman's intuition thing: can't argue that!

[Irulan]

This may be a stupid question, but if you are contorting yourself to measure your sitbones, aren't they moving into a different position? Or is that only in childbirth?

Second, if one knows one's sit bone width, what does one do with that information? Isn't there still some personal preference as to how your newly mapped sit bones contact the seat? It's not like a shoe where the high point of the arch lines up with the high point of the arch support. Or is it?

some manufacturers base their saddles on different widths. The idea is that the saddle should support your sit bones. Specialized sells saddles in 130, 140 and 150 MM widths. The width of the sit bones has no relationship to the size of your *ss, it's about your skeleton and getting supported by the skeleton, not the soft bits. So there is some science to it. I LOVE my Specialize AVG Body Geometry saddles that have been sized to fit me, I have the same one on all my bikes.

[KnottedYet]

Second, if one knows one's sit bone width, what does one do with that information? Isn't there still some personal preference as to how your newly mapped sit bones contact the seat? It's not like a shoe where the high point of the arch lines up with the high point of the arch support. Or is it?

The rule of thumb I've seen is that you add a cm or 2 to each end of your sit bone measurement, and then start looking/trying saddles with at least that width. The wiggle-room margin lets you change positions on the saddle and scootch around without losing the support under your sitz.

As far as where on the saddle your bones contact, that seems to depend on the shape of saddle you like. Some folks have hip joints that work best with a pear shaped saddle and they can really scoot around to adjust to what they are doing on the bike. Or they race, and need to have lots of position options that a pear-shape gives them.

Some folks have hip joints or riding styles that work best on a "T" shaped saddle, and that seems to limit where you can put yourself just because there isn't a gradual transition from sitting part to nose. You're either on the sit part, or on the nose. I do better on "T" saddles, and still feel like I have plenty of scootching room for my easy-going riding style. (I'm just so happy to have a saddle that supports my wildly wide 170-180mm sits, that the saddle just feels miraculous anyway!)

[KnottedYet]

This may be a stupid question, but if you are contorting yourself to measure your sitbones, aren't they moving into a different position? Or is that only in childbirth?

The pelvis is a pretty solid ring, so the parts of it aren't gonna move much in relation to each other. The ischial tuberosities do have a bit of an angle to them (slightly wider posteriorly, and narrowing in the pubic bone direction). The weight-bearing part is pretty built-up bone, but it does retain a bit of that angling. Depending on how you're built and how you roll your pelvis when you measure, you might measure the forward or rearward parts of the sitz. But it's not ususally going to be a huge difference. Whatever bit of the sitz you measure will at least give you a starting point in your search.

The proof is in the ride, so don't get too hung up on measurements. If you find a saddle that you swear should be too narrow, but it feels marvellous, go for it! Same with "mens" saddles. I have honkin' womanly hips (thanks mom!) but the saddle that fits me and lets me ride 50 or 60 miles pain-free is a MEN'S. If you find saddle you like and it happens to be a men's rather than a women's, go for it!

Don't let labels or measurements stop you.

[sandra]

Browsing in the LBS, I just recognized the contours I pictured, bought it and it's been great. A woman's intuition thing: can't argue that!

And what kind did you end up with Look?