Pubic Bone Height & How To Measure Your PBH
Pubic Bone Height (PBH) is easier to define than "leg length." (Inner leg or outer? Floor to...where? And so on.)
PBH is the distance between a hard floor and your pubic BONE. Your pubic bone is inside, so you can't see it. You determine where it is by feel, and here's how:
1. Hold a ruler or yardstick edge-up between your legs and hook the end of a metric metal measuring tape over it. Squeeze the tape between two cheap or free hardware store yardsticks, if you have them. A thin hardcover book can work, too. Metric, remember. If you tell us your PBH in inches and say, "Thirty-one and a half," we'll assume you're rounding roughly. If you're a bike person, you need to have a metric/inch measuring tape.
2. Wearing thin pants and in bare feet (NO SHOES) and WITH YOUR FEET AB0UT 11 INCHES APART, grab the ruler fore-and-aft and pull up until you're pushing hard against bone. Not skin, not flesh, but BONE.
You'll never pull past the bone, so you can't get a reading that's too high. If you do this 100 times, take the highest measurement. If you do it once correctly, that's all we need. In nine cases out of ten, when a customer shows up in person after having measured their PBH at home, we measure it again according to points 1 & 2 above, and it's two to three centimenters more. Up to an inch. Seriously, press against BONE.
PBH determines your saddle height (an ergonomic thing) and your STANDOVER CLEARANCE—how much space between the top tube and your pubic bone when you straddle the bike. You don't "straddle the bike" when you ride it, but if you have to hop off the saddle mid-pedal stroke and spread your legs wide to prevent a fall, a little crotch clearance comes in handy.
With a trustable PBH, the correct frame size of any model we sell is easy. Our chart is accurate. In many cases you'll be able to fit either of two sizes. In those cases, your handlebar shape can be a guide. A drop bar never rises above the stem, so if you like drops AND high bars, get the bigger of two sizes that fit. If you'll ride a Bosco or Tosco bar that rides 2-3.5 inches above the stem clamp, you could probably do well get the smaller bar.