measuring sit bones

[lattae]

Can you ladies tell me how you measure your sit bones, and once you have this info, how can you determine the correct width that a saddle should be?

[sundial]

Well.......the easiest way is to go to your local bike shop and ask them if they have a butt-o-meter. It's a cool device that you sit on and it measures your sit bones. Then you can determine what saddle is the right width for you.

A more difficult way is to take a piece of typing paper, place it on a stool or chair and see if you can make indentions with your sit bones. One TE'er had luck using Play Do to make her sit bone impressions.

Good luck and let us know what you find out.

[velogirl]

whatever you sit on (a little piece of foam would work), you need to elevate your feet to make your sit bones protrude. to do this, just place your feet on a chair at the same height as you are sitting. make sense?

btw, the "saddle measuring tool" is a specialized product, so you need to go to a specialized dealer to use it.

[lattae]

Thank you for the info. Once I obtain my 'sit bone size' is there a certain rule of width that the saddle should be? Should it be a inch or so wider than the sit bone measurement, or exactly the same size?
Hope you understand what I mean. Thank you ladies so much

[velogirl]

measure your sitbones in mm. there are ranges that will be most comfortable for your width and your style of riding.

here's the guideline from the "butt-o-meter" (yes, I have one because I use it for bike fits). the range on the narrow end is intended for those who ride in a more aero position (ie riding forward on the soft tissue), while the range on the wide end is intended for those who ride in a more upright position (ie sitting on their sit bones).

SIT BONE WIDTH -- SADDLE WIDTH RANGE

130-160mm -- 143mm -- 155mm and wider
100-130mm -- 143mm -- 155mm
70-100mm -- 130mm -- 143mm

I've been fitting women (and men) on Specialized saddles for over a year now. I have a saddle demo program with my bike fits. I'd say 60% of the women I fit on a 143mm saddle, 30% on a 155mm and 10% on a 130mm.

[Thorn]

But...that chart doesn't make sense to me. For the narrower measurements, they suggest saddle widths that are wider. If you're built wide, they suddenly switch over and say you can fit a saddle that is narrower than your sit bone width.

I don't mean to be contrary, but do women with wide sit bones actually ride saddles that are narrower than the bone width? By being uninformed I have done so with extremely negative consequences. So, in your experience is that valid or is that marketing from companies that dont' really have non-tractor saddles for wider widths? And I'm not picking on Specialized--I've read this elsewhere. Just curious.

[velogirl]

actually, Specialized has wider saddles in their line-up.

but I'm not sure I understand your question completely. try to remember that these are ranges of sizes and simply recommendations. however, Specialized has done a ton of medical-based biomechanics research, so I believe they know what they're doing in this respect.

Lorri (no, I am not a Specialized employee)

[Thorn]

Sorry, Lorri, confusion is, unfortunately, contagious and I apologize for the thread digression....of course, I'm a statistical outlyer. My sit bones measure at about 140mm. I struggle to find a saddle that is wide enough, firm enough and "gets out of the way" where it needs to "get out of the way".

Anyway, I read the specialized chart and for narrow widths, the saddle widths they recommend are much wider than the sit bone measurements. For example, for 100-130mm, the saddle width (143-155mm) is wider than the widest range. Makes sense. You want to sit on saddle, not the edges.

But then when the sit bone width gets into my range, the saddle width is not always wider than the sit bones. So, I guess my question is, given that you've been fitting people, have you ever fitted someone in the wider sit bone range successfully on a 155mm? My question is more curiousity (e.g., how far of an outlyer am I?) than anything else.

I guess this is the same as lattae's question. The chart gives ranges. Do you start there? Or do you have a rule of thumb you use?

I've toyed with trying one of the 155mm saddles, but I've been unsuccessful on wider Terry's so I'm more than a bit wary.

[Beane]

Couple of things:

1) Trek has a butt-o-meter now too (a friend of a friend was on the design team for their new saddles)

2) I did the specialized measurer thing and was told to buy a 143. I liked it for a while, but no more. The saddle is really uncomfortable. At first I thought it was that there wasn't enough padding for the sit bones, but now I'm thinking that the saddle is a bit too narrow. So I guess my question is: what are the chances that the size they sold me was wrong?

[KnottedYet]

My sits are 170-180mm wide. (depending how forward tilted or "aero" I am)

No kidding.

I work in pelvic rehab, I am friends with many sit bones. Mine are not terribly unusual.

Got to have a nice talk with a very popular brand division head for road bikes this week at a seminar in San Francisco: their widest women's performance saddle isn't even going to be as wide as my sits, let alone give me 1-2 cm wiggle room to each side. Their idea is that women should be sitting on the rami, not the sit bones. Ummm, lets talk about soft tissue damage, shall we? (pelvic rehab training will scare you right out of the idea of weightbearing on your rami, if you can possibly help it!)

I'll be sticking with my 210mm wide Brooks B67.

[velogirl]

I don't think Specialized is recommending you fit on a saddle narrower than your sit bones. You'll note, the top right of the scale indicates "and wider."

I honestly have never measured a woman who had sit bones wider than 160mm. Most have been in the 130-140mm range.

And yes, these are only guidelines. For example, Specialized would fit me on a 143mm saddle. I've been riding a 130mm saddle since 2004. I like it. When I tried the 143mm saddle I ended up with saddle sores.

The fit process doesn't end when someone leaves my office. I guarantee my fit so if someone isn't happy with their fit or satisfied with their saddle, I will see them again until I can make them happy. And in all the years I've been performing fit, I've only ever needed to see someone again twice.

BTW, I've only been demo-ing Specialized saddles for a year but I've been performing bike fit for the past six years.

Now Knotted, tell me more about pelvic rehab. I sit firmly on my soft tissue (not my sit bones) and have been since I started riding about 10 years ago. I've noticed no negative issues.......what should I be looking for?

[KnottedYet]

If you are comfy on your soft tissues it's likely you are on the rami, which is exactly what the new saddles I saw are designed for. They are curved (top surface) to match the "ideal" rami angle for each sitbone width. (in their case, the sitbone width is only used as an indicator of rami angle)

The guy didn't have their widest new saddle for me to try, to see if it did match my rami angle, darn. (my rami are going to have a VERY shallow angle) It isn't in production yet.

There are an awful lot of important muscle attachments and nerves and blood vessels running around in the rami's neighborhood. If the seat top curve doesn't match the rami right, someone will be weightbearing on just a portion of the rami (not the whole thing, just a small contact point) and battering that point and yanking on the soft stuff. Or if it's completely off, they will be off the rami and into the tender goodies or even the pubic bone.

This weekend I rode a borrowed bike with a different brand women's saddle, which was way too narrow. I was definitely weightbearing on the rami, mostly on just one little spot. I'm a hurtin', and it was only a 10 mile ride. If someone tried one of the newer saddles and didn't know what it should feel like (comfy, like you are VG) I would worry about things like pudendal nerve entrapment and blood flow.

The guy was demo-ing with a female pelvis model and a sample of the 146mm saddle, and I was cringing at the thought of damage to those of us who don't match the statistics.

I was impressed that saddle designers are finally getting away from the oat-bran trendiness of over padded saddles and cut outs for women.

[OakLeaf]

I was impressed that saddle designers are finally getting away from the oat-bran trendiness of over padded saddles and cut outs for women.

Do you think that cutouts are always inappropriate? Or just for some women? (I have a hard time picturing where I'd put my very large, um, parts on a saddle without a cutout.)

[KnottedYet]

Do you think that cutouts are always inappropriate? Or just for some women? (I have a hard time picturing where I'd put my very large, um, parts on a saddle without a cutout.)

Oh, no! There are definitely folks and riding styles who need cut outs! What was starting to drive me up the wall was the way the women's saddles were getting gratuitiously over padded and over-cutoutted.

Like some company exec said "here, copy this Terry saddle for me, but make it more padded cuz it looks uncomfortable."

[KnottedYet]

Oh, and as far as statistics and sitbone widths I see; my sample is biased in that I'm seeing the women who have pelvic problems already. The ones who've always been miserable on a bike and never got into riding because it hurt too much.

They couldn't find equipment to fit them, so they never fell in love with riding, never got into a group like Velo Girls, never went to a coach for a fit, AND since they weren't serious bikers they never got included in the statistical samples used to design saddles.

It drives me nuts.