Do I have abnormal sit bones?
 

I'm new to cycling, so I measured my sit bones using the ol' flour in a ziplog bag trick. From the center of one dimple to the other, it's 145mm-150mm. According to various websites, I should get a saddle that's 2cm bigger than my sit bones. However, I'm unable to find road bike saddles that are 170mm. Did I somehow measure wrong, or do I genuinely have a big *ss?
Thanks!

Did you lean forward or sit up straight? You should have been leaning forward, or at least in the position you will be riding in. Sit bones narrow up as you lean.

I've never used or heard about your flour method.

If you measured correctly, they are abnormally wide. But if you measured correctly, they're what you got.

How about Brooks -- either the Cambium 17 @ 164mm W, or the Cambium 19 @ 184mm W? Neither is spot-on your 170mm number, but they're relatively close. Either might work for you.

1) 99.9% you measured it wrong. 2) This width doesn't mean much if anything at all.

I have to see posted X-ray images to judge .. they're digital these days..

Specialized Power in 168mm width would be a good choice then.

I have pretty wide sit bones myself and I actually rode on that saddle in 168mm width and I was fine on it, but it broke in a crash after a year of use, and I replaced it with a 155mm version (also slammed the stem which makes for a narrower stance) which I am also fine with.

Wider version was perhaps a bit nicer when sitting fairly upright on a long climb, narrower is perhaps a bit nicer for hammering it in the drops for the better part of a hour on the flat, but I got on great with both, including various 200+km rides.

Brooks B17 is 175 mm; Berthoud Aubisque is 180 mm. My sit bones are almost too far apart for the Brooks; anything narrower does not work for me.

Brooks C 19 is sit up Dutch Bike Wide..