Most bikes are built for men
For years women have been riding bikes designed part-
ly, if not totally, for men. For the lucky ones, their dealer
substituted a few parts which made their men's bike work
pretty well for a woman, especially in larger sizes.
Adaptation and adjustability
Fitting bikes is a combination of adjusting a bike and
adapting the rider.
Larger bike are more adjustable, since their stem
lengths are usually of average length and rise. On a
small bike, the stem is likely to be quite short. If an
even shorter stem is desired, the right extension may
not exist. Changing the rise angle of a very short stem
has little effect on handlebar height so vertical adjust-
ment is not readily available, either.
When analyzing movement of a person, the range of
motion is critical to efficiency and power. If you move
a fit component on a bicycle a given amount, it will
effect the range of motion of a person with shorter limbs
more than a person with longer limbs. Simply put, when
fitting a bike a shorter person has less adaptability
than a taller person. Smaller bikes generally have less
adjustability than big bikes, so it's more important that
a small bike fit just right.
Smaller women rider smaller bikes. With less available
adjustment on their bikes, and less adaptability of their
bodies, small women have suffered fit problems that
lead to performance gaps. Serious riding on the road
is much more fun when your bike is comfortable and
handles well. Off road, anything less can make cycling
really unpleasant.
More than a dropped top tube
The new WSD bikes are spec'd with women's specific
components, like saddles, bars, and crank lengths. The
WSD mountain bikes have women's specific suspension
forks with softer springs.
More importantly, these frames are a completely dif-
ferent geometry than the men's bikes. So while most
`women's' bikes make due by just tweaking a mens bike
with a few add-ons or maybe a dropped top tube, we
completely redesigned these bikes to meet the needs of
performance oriented smaller women.
Women sit on a bike differently
There are several major differences in how men and
women sit on a bike. The most obvious and most dis-
cussed of these is the difference in pelvic structure. A
woman's hips are wider, and the bony protuberances
we all sit on, called ischial tuberosities, are also wider
apart. This accounts for the popularity of women's sad-
dles that are wider in the back than a man's.
A man's pelvic structure allows him to roll his pelvis
forward on the saddle and lean forward aggressively.
For most women, this hurts. The result is a woman
sits on a bike seat with her pelvis in a more upright
position. For the smaller woman on a man's machine,
this means her lower back is curved and the handlebars
are hard to reach.
Adjusting geometry to fit women
Trek engineers addressed these issues in several ways
in the WSD geometry. To support their wider pelvis,
women tend to sit further back on the saddle. With a
steeper seat tube, the seat can be positioned placing
the legs over the cranks for optimal power, while her
butt is on the most comfortable part of the saddle. To
adjust the reach for a more upright angle to the back,
a shorter top tube is used. The handlebars are placed
higher by using a taller head tube, so her back and
arms can be at a relaxed angle for steering control and
shock absorption.
These adjustments put a woman in a more comfort-
able and powerful position. That makes hills easier
and long rides less tiring. A common complaint among
women riders is back pain, and the correct position
goes a long way to alleviate this problem.
Some of the corrections Trek made to these frames
can be made to a men's frame with similar results,
especially with a taller woman's bike where there is
more adjustment. But any frame will handle its best
with the weight distribution applied in a certain way,
and a men's frame is designed to have a man's heavy
shoulders pressed firmly onto the handlebars in a bent
over position. When you put a woman, who already has
lighter shoulders, in a more upright position, there is
much less weight on the front wheel. The result is less
steering stability and for her the bike may be harder
to control.
Steering and weight distribution
Steering stability on a bike is a combination of trail
and centering force. Trail is the distance from the
steering axis at the ground to the tire contact patch.
But for trail to make a bike stable, there needs to be
weight on the bars to apply a centering effect. The
greater the weight on the bars the more stable a given
bike will be. This is why a touring bike with front
panniers is more stable than it would be with only rear
panniers.
A smaller man on a small bike still applies plenty
of centering force for good steering and handling. To
achieve a similar amount of steering stability for a
small woman in a more upright position, more trail
is needed. Not only does stability lend confidence to
the rider, it also means that less strength is required
to hold the bike in a line. This again addresses an
important difference between men and women, that of
upper body strength. By decreasing the head angle of
the women's bike, she will get similar handling with
a similar `feel' to that designed into a man's bike for
a man.
Women's road bike geometry
Most women have only been able to choose from a
single category of bike design; men's. On taller women,
this choice was often satisfactory. Perhaps a few easy
changes were necessary, such as a shorter stem and
adjusting a different, ladies saddle further forward.
Smaller women found it much harder to get a good fit
and even if the fit was accomplished, performance on
the small bike often suffered.
Some companies tried to address this by using short-
er top tubes coupled to shorter seat tubes. This may
have helped some, but the usual compromise on these
attempts was to raise the bottom bracket considerably.
Why the high bottom bracket? As the top tube is short-
ened, the toe clearance around the front wheel is com-
promised. Raising the bottom bracket alleviates this
somewhat. This doesn't help with an already restricted
standover. Raising your center of gravity doesn't help
the bike's handling, instead making it tippy and pre-
carious in corners. An additional problem is that rais-
ing the bottom bracket without adjusting the handle-
bar position upward puts the bars lower, when the bars
Trek 2002 Tech Manual
WSD (Women's Specific Design)
