another brooks question: your brooks type and your handlebar height/type

[KnottedYet]

The cantle plate eats the last cm of the saddle on each side.

You want a Brooks (or any other suspended leather saddle) to be about 2 cm wider than your OUTSIDE measurement. Your bones do not want to be landing on the metal cantle plate.

BleeckerStGirl wrote a great description of how she felt on a B17 vs a B67/68. She was hitting the cantle plate a little on the B17.

Chaffing is all about the transition from sit to nose being too gradual for the particular angle of someone's hip joints. Like Sundial noted, sometimes a wider saddle will also have a wider transition/wider nose. (that wider and more gradual transition is what people are talking about when they mention pear/wedge vs T shaped saddles)

[_kim_]

sundial: this saddle will be for a commuter/touring-type bike.

knot: so, the outer-to-outer measurement of the laughably huge, 2.5" circles that i created on the tinfoil was about 203mm. based upon your most recent post, perhaps i would find a 205mm width (i.e. B67 or 68) saddle better after all? i gotta say, if i don't get that super wide saddle, i'm probably going to be forever wondering whether it would be right for me. (or at least until i gave up with a 175 mm one and got a 205mm one...) and thanks for the cantle plate info. i certainly do not want to be sitting directly on that.
i'll look for bleeckerstgirl's post.

[KnottedYet]

Nope.

Those circles are not exactly your sit bones.
(I measure with a measuring tape directly on the bones.)

Try sitting on your hands and feeling the contours of the bones. Get your index fingers on the outsides of those bones, jammed right up to them. Leave your hands on the chair and stand up, have someone measure the distance between your finger tips.

Outside measurements are only about a cm two more than center measurements most of the time.

If we use your 150mm centers and add a couple cm, we get your outside at around 170mm. If we use your 140mm centers and only add 1 cm, we get outside around 150mm. Take a B17 at 175mm, subtract 2 cm for the cantleplate: someone with 155mm outside and LESS won't be likely to hit the cantleplate.

Depending on your imprints, your actual outside measurements could be right on 152 or they could be out there in the 170s. That's why its so important to measure a few ways and a few times.

[sundial]

Chaffing is all about the transition from sit to nose being too gradual for the particular angle of someone's hip joints.

You always put it so eloquently.

[_kim_]

ok, i will try that sitting on hands/having someone else measure when i stand up thing. that "add 2 cm" (to your outside sit bone measurement) guideline is very helpful.

and i agree, that is a good explanation of chafing--and it reminds me of one other question i had (hopefully my last or nearly my last for now!), that of the S brooks saddles vs. the men's. after i learned that the "S" design was mainly to accommodate skirts, i began to seriously doubt its usefulness to me as, well, i rarely wear skirts (or skorts). plus, wouldn't the S saddles be a little more pear shaped/have a more gradual transition from seat to nose, thus increasing the risk of chafing?

[Biciclista]

and I now have a brooks imperial saddle. it has a cut out and I absolutely love it (B68)
There is NO WAY i am ever trying another kind of saddle ever again.

oh and I have a roadbike with curved down handlebars (not what you see in my avatar)

[sundial]

after i learned that the "S" design was mainly to accommodate skirts, i began to seriously doubt its usefulness to me as, well, i rarely wear skirts (or skorts). plus, wouldn't the S saddles be a little more pear shaped/have a more gradual transition from seat to nose, thus increasing the risk of chafing?

Well, yes and no. Some riders prefer the longer nose saddle for better control on the bike. I prefer the shorter nose saddle and I feel in control of my bike and I have ample wiggle room. I have the shorter nose saddle on bikes that I sit more upright and I don't experience the chaffing. But on a road bike I went with the longer nose saddle because of the chaffing issue of a pear shaped women's saddle. Also, the women's Brooks saddles have shorter rails and you will probably need a setback seatpost to get your saddle adjusted to the right fore/aft position.

For a comparison of saddles, take a look at this.