Tuesday, December 19, 2006

Saddle Height

I’ve been told many times by the rider behind me in a pace line that I rock too much in the saddle. If I’d only heard this once or twice I might dismiss it as a bad day, because I don’t feel like I move around too much. But I obviously do, because I get the comment more than infrequently and it's usually from folks who know a little bit about riding a bike (translation: they’re faster than I am). If I thought efficiency wasn't involved, I wouldn't waste my time trying worrying about it, but methinks it does makes a difference, maybe a significant one.

I’ve experimented with saddle height before, I've read many opinions about how do determine it, and I've been fitted on a bike once or twice. But I think my saddle height sort of migrates higher over time because I’m accustomed to it more than anything else. So I have decided to take a more scientific approach and see what happens.

My saddle height has been about 36.5” from saddle top to center of pedal axle, which is shown as length 1 in the figure below.

Saddle Height is dimension 1 Trochanter height is 76 in this figure

Here are the studies that I’ve found and the corresponding saddle height that would be recommended for me:
35.3” Hamley & Thomas, 1967 – 1.0 x (trochanter height)
34.9” Hamley & Thomas, 1967 – 1.09 x (inseam height)
35.3” Shennum & DeVries, 1975 – 1.0 x (trochanter height)
35.3” Nordeen & Cavanagh, 1975 – 1.0 x (trochanter height)
37.1” Nordeen & Snyder, 1977 – 1.05 x (trochanter height)
??.?” Genzling, 1978 – 25 to 30 degree knee bend
35.4” LeMond, 1987 – 0.883 x (inseam height) – 3mm

Some of these studies are a little vague about whether the measurements are including shoes, etc. It’s obvious from the dates of the above studies that saddle height research is no longer a hot research topic, but it has been researched a lot – the above list is just a sample of the available studies.

So it looks like I need to lower my saddle about an inch to 35.3 inches. I plan to try that and see if I feel more stable on the saddle and see if I notice any differences in power, fatigue, etc.

It’s interesting to note that based on the above guidelines, my wife, Betty Jean, needs to lower her saddle almost 2 inches! I think I’ll recommend that she lower it about an inch and see what happens. An inch is an awful lot in saddle height. And even thought we probably should lower it gradually, we’re going to go whole hog and see what happens.

I might find out that I was already at my optimal saddle height and that I'm just a Jim Furyk of cycling, but I doubt it.