DISTANCE BETWEEN SIT BONES VS. SEAT WIDTH
June 27, 2006
Back to questions
A friend of mine is having a
hard time finding a good fitting road bike seat. I don't
have a good direction to point him in, other than telling
him to go to a bike store and try out the different widths
He measured his sit bones at 100
mm. Is there any kind of chart in existence that shows an
ideal seat width vs. sit bone width?
Also, he said the left side of the
point of his seat shows signs of wear (on more than one
seat) even though it's pointed correctly on the bike. I'm
guessing he's twisting somehow as he pedals but I don't
know what a reason might be or how to correct it. I told
him to twist his seat off center. Thanks.
A couple of manufacturers, such
have such a chartbut it applies only to their products.
You couldnt make a manufacturer-agnostic chart, cuz
two different manufacturers could make two different saddle
widths for the same, uh, butt size.
I like your idea of going to a bike
shop and trying different seat widths. First, youd
need a good measurement between your sit bones: Place a
piece of corrugated cardboard on a low surface such as curb.
Sit on it, then immediately lean forward to the position
in which youd normally sit on your bike. (Sit bones
tend to move closer together when one leans forward.) Get
up, then measure the distance between the middle of each
depression in the cardboard.
Bring your ruler to the bike shop.
Grab a seat and try to measure the distance between the
center of each of the seats rear pads, and find one
that best matches your sit-bone width. Because different
manufacturers make rear pads of different sizes, the center
points might not seem obvious (which makes this method less
scientific than we might like).
Having more wear on one side of
the seat could come from a few different things. You could
have one leg longer than the other, have a misaligned skeleton,
lean to one side while you ride, or mount and dismount on
one side more than the other.
Learn more about seat comfort here,
and about different seat types from my book, Urban
Bikers Tricks & Tips.