I am in the process of working on Bicycling for Women, which is a complete overhaul of all the information in my first book, The Female Cyclist: Gearing up a Level. We decided not to call the new work a second edition due to the large scale of updates and complete revisions in the book. While working on Bicycling for Women, it conjures up fine memories of the most difficult chapter in the first book. The chapter that took me the most time and was the most stressful, was the chapter on equipment and bike fit.
The early research included a few different methodologies for determining seat height. Including a handful of methods to estimate seat height seemed like a reasonable thing to do, no problem. While doing the work on the seat height section, every piece of information I found on bike fit for women said that "women have shorter torsos than men" and therefore bike fit needs to be different for a man than for a woman.
Having some experience in ergonomics (the science of obtaining a correct match between the metrics of the human body, work-related tasks, and work tools) I decided it would be really fun to include outline drawings of a male and female body and display the actual differences in average body measurements between the two.
This is where the trouble began.
Every piece of literature, and I mean everything, in the bike industry touted the women-and-short-torso thing. The trouble was, I could find nothing - no data - to prove that statement to be true.
My ergonomics data came from NASA studies. The data there did not support that women have short torsos.
I checked with the anthropology department at Colorado State University. They identify skeletal remains from years and years ago. Nope, no short torso support there.
I checked with a forensic pathologist. These people ID bodies all the time. How about it doc, any short-torso female evidence, some data? Humph, none here either.
I checked with bike fit guru Andy Pruitt. Did he see that women are typically short in the torso compared to men? No.
I went to legendary frame builder Lennard Zinn to see if he had data in all of his body measuring files. No. He did say that he sees more body dimension similarities of people with similar ethnic backgrounds; but as a rule, he could not support that women have short torsos compared to men.
Now I'm really nervous. I went ahead and wrote the chapter and disagreed with all published information about bike fit for women. I laid out all the data I could find, disproving the short torso claims. The book went to press and was published in 1999 (not that long ago). Then I waited.
Each time I saw another ad for a "women's specific bike" manufactured especially for women because of their short torsos, I dropped the manufacturer a note. I asked to please send me the data that proves women have short torsos, when compared to men.
Most of the time I did not get a response. On a few occasions, people did respond and said that's the information their engineers had given them. When they went to dig out the data...nothing.
I still see the short-torso claims printed from time to time. Each time, I send a note to ask for the data to support the short-torso statement. If you have any data proving women have short torsos, when compared to men, please send it my way.
This whole investigation brought up a string of issues. The domino affect. I'll get to those issues in future blogs.
I'll leave you with something to ponder. What other "common knowledge" is not factual, but some sort of misinformation passed on from person to person? I don't think the information on short torsos was intentionally bad, rather I suspect someone measured a very small sample size of women and men, then concluded all women have short torsos. Perhaps the sample size was one.
It never hurts to ask, "Where's the data?"
See where the question leads you ~