Most saddle advice for women starts with a checkbox. It asks what gender you are before it asks how far apart your sit bones sit. That order creates problems. Sit bone distance doesn't split along gender lines. Two women can differ by 20 mm or more. Two riders of different genders can share the same sit bone width. The checkbox is a shortcut that skips the measurement determining whether a saddle hurts or fades into the background on a long ride.
A 2023 study of female cyclists found nearly half reported long-term genital swelling or asymmetry. Another survey put vulvar swelling at 35 percent. Many of those riders were on saddles marketed as women's models. The category didn't protect them. A saddle that doesn't match your sit bone distance will cause pressure no matter what label it carries.
Averaging Pelvises Created a Category That Fit Few Real Riders
For decades, saddle makers handled women's fit by widening the rear and shortening the nose. They assumed wider hips mean wider sit bones. That assumption conflates two different pelvic measurements. The bones that bear weight on a saddle are the ischial tuberosities, not the iliac crests. Pelvic width and sit bone width don't track together. A rider with narrow hips can have wide sit bones. A rider with wide hips can have narrow sit bones.
Building a women's saddle on an average pelvis produced a product category that fit very few real riders. Women with narrow sit bones ended up on saddles too wide, which caused inner thigh chafing. Women who needed more width ended up on models too narrow, which pressed soft tissue into the saddle and cut off blood flow. Both failures came from the same source: gender used as a sizing proxy.
One Measurement Changes the Whole Approach
Sit bone width, measured center-to-center between the ischial tuberosities, is the starting point. A rule of thumb is to add 20 to 30 millimeters to that measurement for saddle width. But that number also shifts with riding position. In an aggressive road position with a forward-rotated pelvis, the sit bones carry less load and the soft tissue needs more relief. In an upright position, the sit bones carry more weight and often need a wider platform.
Bisaddle addresses this with an adjustable base. The saddle's two halves slide apart or together from 100 mm to 175 mm. You set the rear width to your sit bone distance. If you switch to a triathlon aero position, you narrow the front to reduce pressure on the pubic bone. If you return to a relaxed commuter position, you widen it again. One saddle reconfigures instead of buying a new model for each discipline.
Soft Padding Is Not a Substitute for Correct Width
There's a cultural assumption that more padding and more width equal more comfort for women. That assumption fails under compression. Soft padding collapses under the sit bones and pushes upward in the middle, increasing pressure on soft tissue. The result can be numbness, swelling, and saddle sores that don't show up for hours.
Bisaddle's split design creates a central gap when the halves sit apart. That gap removes pressure from the perineum the way a cutout does, but its width is adjustable. A rider with 130 mm sit bones can set a wider gap than a rider with 110 mm sit bones. That single setting determines whether blood flow and nerve function stay intact on a six-hour ride.
A Fit Process You Can Do at Home
Start with a piece of corrugated cardboard and a hard chair. Sit on the cardboard, lean slightly forward into your riding position, and find the two deepest indentations. Measure center-to-center in millimeters. That's your sit bone distance.
- Add 20 to 30 millimeters to get a starting saddle width.
- Set your Bisaddle halves to that width.
- Ride for 30 to 60 minutes on a trainer.
- Check for two failure signals.
- Sharp pressure on the soft tissue between the sit bones means the saddle is too narrow or the central gap is too small.
- Rubbing on the inner thighs or sliding onto the nose to get comfortable means the saddle is too wide.
If you feel sharp pressure, widen the halves or increase the gap. If you feel rubbing, narrow the halves a few millimeters. Repeat the ride and adjust until you can sit without numbness or hot spots.
Because the width adjustment is mechanical, you can test both directions without buying two saddles. You can also revise the width later if your flexibility changes, if you switch to a triathlon bike, or if your weight changes. A fixed-shape saddle locks you into one measurement. Bisaddle lets you update the measurement as your body changes.
Where Saddle Width Is Heading
Pressure mapping data shows peak pressure under the pubic bone drops when the saddle matches the rider's sit bone distance. That data doesn't care about gender. As more riders understand this, fixed gendered saddles look like what they are: an approximation from an era before adjustable hardware.
Bisaddle's Saint model already pairs an adjustable base with a 3D-printed foam lattice surface. That combination lets you tune both structural width and surface cushioning. Future versions could add live pressure mapping feedback, so you can watch the pressure distribution change while you adjust the halves. The principle doesn't change: measure the bones, then adjust the saddle to the bones.
The Measurement Comes First
Saddle choice starts with two numbers: sit bone distance and riding position. Those numbers don't respect gender categories. Bisaddle's adjustable width turns saddle selection from a categorical guess into a repeatable measurement. Measure your sit bones, set the width, ride, and adjust. Finish a long ride without pain. That's the measure that matters.
