Continuing this discussion of bottom bracket height comparisons I thought I could add some inside information about some fixturing in England. The ones I was familiar with were not calibrated by bottom bracket drop but rather had settings measured in bottom bracket height - which means they assumed a certain wheel diameter to establish what those height settings were. The Johnny Berry fixture I brought back (similar to the F.W. Evans design fixture) had a rectangle plate with an offset hole that could set the distance of the bottom bracket holder to the wheel base line by turning it to one of the 4 settings that were measured in 1/4" increments. In other words, the fixture could be set as marked at 10 1/2" bottom Bracket height. The bottom bracket holder on the master fixture at Ellis Briggs (which I thought the best one I had seen in England) could be moved on a slot to any bb drop but was measured by marks indicating bb height. This is a pretty small sample but I'm guessing was consistent with other English builder methods. It also had wheel line adjustments for either 26 or 27 inch wheels.
Concerning the possibility of an English trend of having higher bottom bracket heights than their Italian or French neighbors, I'm guessing these frames that came to the states were designed more for our market than theirs. Remember that the time in the US before Greg LeMond went to Europe (and influenced later frame design), there was a strong request for criterium style frames where steep angles and high bottom brackets were the US fashion. The then "modern" design was short chain stays and deep handlebar droops for going quick around city blocks - which was the type of racing most common. Also buying these frames was a fairly young demographic so even if they didn't have a racing license, they wanted stuff as if they were. When Greg went to Europe and the Continental experts revised his American frames for long days in the saddle. His saddle went back (and therefore his seat angle) and there wasn't the need for twitchy steering in stage races. Frames designed for long road races instead of criteriums now became popular when word of what Greg rode got around in the states.
Now I'm going back to making a bike frame for my 19 year old daughter which I designed to use with 26" tubulars that have a wheel diameter of 626mm. I wanted the bottom bracket height to be a smidge over 10" so I made the drop to be 57mm. Lets do the math, 626 divided by 2 = a 313 tire radius, subtract the 57 bottom bracket drop = 256mm (10 1/16") bottom bracket height. She will use 170mm crank arms. I'm documenting this whole frame build with pictures and accompanying text.
Doug Fattic
Niles, Michigan USA