Saddle fit [03] Saddle shape

Saddle fit [03] Saddle shape

Updated: 16/11/2018.

This post, third in the series about bicycle saddles, explains what kinds of saddle shapes there are and which to choose according to one’s needs and riding style. Previous two posts explain bicycle saddle material and padding. While the next post will explain sizing (width primarily).

Saddle shapes differ in the following attributes:

  1. Waviness from nose to the back
  2. Curvature from the sides towards the middle
  3. Pear vs T shaped profile (looking from the top)
  4. Cutout in the middle

 

1. Waviness from nose to the back

By this criteria, there are three types of saddles: flat, waved and moderately waved.

1.1. Flat saddles

Picture 1 Flat saddle Source: www.fizik.com
Picture 1
Flat saddle
Source: www.fizik.com

Flat saddles are practically completely flat – i.e. there are no raised, nor lowered areas in along the front to back axis.

Such saddles are good for upright riding posture, as well as for highly flexible riders in more leaned riding posture, like shown in pictures 2 and 3.

Advantage of a flat saddle is the ability to easily alter saddle position – sliding from front to back and reverse. Some riders like this and find that position changes provide more comfort, while the ease of position changes on a flat saddle is good for fast riding – with moving more forward when leaning more, and moving back when riding more upright.

This can be particularly useful on road bikes, with multiple hand positions on the (drop) bars. Flat saddles can also be good bicycles ridden more upright (rider flexibility isn’t important there). Still, some riders, even flexible ones, don’t like the ease of sliding back and forth and prefer a saddle that keeps them more stabily in place. There come the other shape – waved saddles.

1.2. Waved saddles

Picture 4 Waved saddle Source: www.fizik.com
Picture 4
Waved saddle
Source: www.fizik.com

Waved saddles have raised rear part, that slopes down towards the middle, then flattening along the front part of the saddle.

Such saddles are preffered by not very flexible riders who ride in a leaned forward position. They also suit riders who don’t like to change sitting position (back and forth), but prefer a saddle that holds them more stably in (one) place.

As can be seen from picture 6, when a not very flexible rider leans forward, the pelvis turns as well. This, for the pubic area, produces the effect similar to tilting the saddle nose higher up by 10 or more degrees. A flat saddle would be more likely to cause pubic area (sof tissue) discomfort. That is why such riders often find waved saddles more comfortable.

1.3. Moderately waved saddles

Picture 7 Moderately flat / waved saddle Source: www.fizik.com
Picture 7
Moderately flat / waved saddle
Source: www.fizik.com

Moderately waved saddles are not completely flat, but the curvature is much less accentuated than with waved saddles. By all the pros and cons they lie between the flat and the waved saddles. So they are most likely to suit moderately flexible riders in a leaned position, or bicycles with semi-upright riding position.

Having said all this, there is also a variation in average sit bone shap of men and women. Women tend to have wider sit bones, with a less raised pubic arch (picture 8).

Picture 8 Male and female pubic bone "height" Source: www.sq-lab.com
Picture 8
Male and female pubic bone “height”
Source: www.sq-lab.com

For this reason, a woman of the same flexibility and riding posture, would effectively load the saddle similar to a man that is bent forward more – and will more likely require a more waved saddle.

 

2. Curvature from the sides towards the middle

By this criteria saddles can be roughly divided into two groups: (more, or less) flat and (very) curved. With numerous variations between the two extremes.

2.1. (Almost completely) flat saddles

These saddles are flat, i.e. sides of the saddle are at (almost) the same height as the middle of the saddle.

Picture 8 Flat (left) and curved (right) saddle Source: www.randorichard.com
Picture 9
Flat (left) and curved (right) saddle
Source: www.randorichard.com

Flat saddles provide less pressure in the pubic area, but allow more left to right sliding of the body, compared to the curved saddles.

2.2. Curved saddles

Curved saddles keep the body more centered, but can cause more pubic area pressure/discomfort, as it is shown in the picture 10 below.

Picture 9 Curved saddle (left) and flat saddle (right) Source: www.cervelo.com
Picture 10
Curved saddle (left) and flat saddle (right)
Source: www.cervelo.com

 

3. Pear vs T shaped profile (looking from the top)

Saddle shape, looking from the top, can be pear shaped (with a more gradual transit from the wide rear area, to the narrower front area), or T letter shaped (with a more abrupt narrowing towards the front part). The difference is shown in the pictrue 11, with a pear shaped white Selle San Marco Concor saddle picture layered over a T shaped grey Selle Italia Flite saddle picture.

Picture 10 A white pear shaped saddle layered over a grey T shaped saddle Source: www.fitworkscycling.com
Picture 11
A white pear shaped saddle layered over a grey T shaped saddle
Source: www.fitworkscycling.com

T shaped saddles often provide more comfort in the area where thighs rub (while pedalling) the saddle. Pear shaped saddles are prefered by riders who like to change fore and aft sitting position while riding. They generally provide more support when the body is moved forward in the saddle.

Here it is important to mention that, depending on the fore-aft sitting position (most often) used while riding, the saddle width varies depending on the saddle’s T or pear shape. For example, comparing two saddles of the same (maximal) width, a T shaped saddle will be wider in the rear part of the saddle, but it will be narrower in the middle part of the saddle, than a pear shaped saddle (of the same maximal width). And vice-versa.

Body should lean with sit bones on the saddle, while thighs should not chafe the saddle sides, only the “front” sides of the saddle (picture 12).

Picture 12 Saddle load (contact points) Source: www.kontactbike.com
Picture 12
Saddle load (contact points)
Source: www.kontactbike.com

 

4. Cutout in the middle

There are saddles with a cutout in the middle, full saddles (with no cutout) and saddles with a “relief channel” (but without a cutout).

4.1. Saddle with a cutout in the middle

Picture 11 A saddle with a cutout in the middle Source: www.fizik.com
Picture 13
A saddle with a cutout in the middle
Source: www.fizik.com

Cutout in the middle relieves pubic (soft tissue) area in the greatest part, and provides ventilation, which is good in the summer and not so good in the winter. 🙂

Depending on the sharpness of the saddle curve around the cutout, some riders find the edge of the cutout to cause discomfort.

4.2. Full (solid) saddles

Picture 12 Full (solid) saddle Source: www.fizik.com
Picture 14
Full (solid) saddle
Source: www.fizik.com

These saddles are completely full, without any cutouts or indentations in the middle. They provide the most support and comfort, but the least pubic area relief.

A good way for a rider to deterimne whether they need a saddle cutout, or could use a full saddle is the following:

  • Sit on a hard wooden (or concrete) bench, so that the knees are bent at about 90 degrees, and the back is straight.
  • Keeping the back straight, bend forward (at the waist) untill the elbows can rest on the knees.
  • Stay in that position for 5 minutes (best to measure).

If there’s no discomfort/pressure in the pubic area, then the “test subject” is fit for a full (solid) saddle. If there is pressure/discomfort, then a saddle with a cutout (or a relief channel) is a better choice.

4.3. Saddle with a relief channel in the middle

Picture 13 Saddle with a relief channel Source: www.fizik.com
Picture 15
Saddle with a relief channel
Source: www.fizik.com

By all the pros and cons somewhere in between a full (solid) saddle and a saddle with a cutout.

Gremlin TIP

When it comes to choosing the righ saddle, there are a lot of exceptions to the rules. For example – some flexible riders prefer waved saddles. The only valid measure is to try for oneself. This series of saddle posts is ment to serve more as a guideline – so one can know where to start when choosing and trying a new saddle, or, if the current saddle causes discomfort – to know in which “direction” to look for a change. I.e. what effect is a different saddle shape most likely to make.

A very important atribute – saddle width, is explained in a separate post: Optimal bicycle saddle width, but first sit bones need to be measured according to these instructions – Measuring sit bone width.

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