Choosing the Right Saddle part 3: Saddle Shape

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How does saddle shape influence your comfort?  If you look at the huge range of saddles available on the market one thing becomes very clear: saddle shape varies enormously.  A small change in shape between two otherwise similar saddles can turn an uncomfortable saddle into one that is so good you don’t even notice you’re sitting on it.  Your saddle, perhaps more than any other component on your bike, is so crucial for comfort and position that it’s worth examining its shape in more detail.

There is quite a difference in saddle shape when comparing the range of modern, science-inspired ergonomic saddles the shape of old school saddles like the Sella Italia SLR, particularly if you wish to ride without saddle soreness in a race position.  Shape has a massive and often decisive impact on your posture and position, with ergonomically designed saddles making it far easier to achieve an ideal posture / position without discomfort.  In this blog I’ll take a brief look at how saddle designed has evolved using three different saddles from one brand (Specialised).  

When you look at the SHAPE of a saddle, there are three views to consider.  If you have been struggling to find a comfortable saddle I have listed a few things to look at under each view:

  1. Top view:
    • How arrow-like or squared off is the transition from the nose the wider part of the saddle?
    • How wide is the saddle nose? In some cases this can be too wide and cause friction against your inner thigh.
    • Is there a channel / cut-out and if so how wide and what shape?
  2. Side / lateral view:
    • Is there a “lateral groove” and if so how deep is it? This lateral groove can be very important in unloading your perineum. 
    • Alternatively is the saddle completely or nearly flat when viewed from the side?
    • Does the hard shell (underneath the padding) curve over to face downwards or does to project sideways and run the risk of digging into your groin or thigh muscles?
  3. Rear view:
    • The shape when viewed from the back of the saddle influences effective saddle width (***see prev blog***) and also influences the ease of changing body position for high speed cornering.
    • An excessive rounded profile can result in the central section of the saddle pressing upwards into your perineum – not a comfortable feeling!
    • A completely flat saddle that has no round-off at all can make it harder for some riders to shift their weight laterally when cornering at race pace.

Lateral View: Saddle Shape and Unloading the Perineum

As an example to explain the impact of saddle shape, I have taken some photos of 3 different saddles in the range offered by Specialised to illustrate how shape can vary dramatically when viewed from the side.  From top to bottom the saddles are: Power saddle, Phenom saddle, Toupe saddle. 

Looking from the side you can see the Power saddle has a groove whose maximum depth is 7-10mm (it seems to vary between actual saddles), which incidentally is about the deepest groove available on the market and is similar to the groove on a Sella SMP saddle.  This would represent a more modern ergonomic design and perhaps not surprisingly is the biggest seller for this brand of saddles for road racing cyclists. 

The Phenom, which could be viewed as a transition from the old classic flat saddle (the Toupe) to a more modern design has a moderately large lateral groove with a maximum depth of 7mm.  It is often suitable for someone with a moderately aggressive position and has been very popular amongst cross country mountain bikers. 

The Toupe, which according to the local bike shop has the lowest sales figures, is almost pancake flat and is the least likely to be comfortable for your perineal soft tissues.  This doesn’t mean it will be a problem for everyone; after all Tom Boonen was reported to love this saddle.

Judging by the sales figures you can see where most people are finding comfort and it’s not in the old school saddle shapes.  This certainly holds true in my clinic and with the bike fit clients I see. 

In selecting a saddle here are some rough rules of thumb that might assist you in your selection when it comes to evaluating the saddle from the lateral view:

  1. Depth of lateral groove:
    • The most ergonomic saddles have a lateral groove whose maximum depth is between 7-10mm.
    • The least ergonomic saddles have no or a negligible lateral groove.
    • Moderately ergonomic saddles have a lateral groove 4-6mm in depth.
    • The depth of the lateral groove is one way a saddle manufacturer can design a saddle to help unload the perineum and prevent saddle soreness, so it is certainly worthy of consideration in your next saddle purchase.
  2. Hard shell – does it project downwards or laterally?
    • Shells that project laterally rather than curving straight down have the potential to cut into your groin / inner thigh muscles. An example would be the Specialised Power saddle and this is a recognised complaint for this saddle amongst riders I have fit (it is otherwise a well-designed product with many riders still using it comfortably).  Specialised have improved this saddle this year, releasing a new version called the Power Arc saddle, with the shell pointing downwards and out of the way of your inner thigh.  It is a significant improvement on their original design and addresses the issue of the hard shell potentially rubbing against the inner thigh.
    • Some saddles have a large area on the side with the shell being curved downwards and padded to guide your thighs when pedaling (unless the saddle nose is too wide). Examples of saddles with a large downward facing area to guide the thighs include the Sella SMP range of saddles and Cobb Max.

 

SADDLE SHAPE: LATERAL VIEW: how deep is the lateral groove?
Specialised saddles: Power (7-10mm), Phenom (7mm), Toupe (negligible). 




Each has a different depth of lateral groove (arrows).  In the Power saddle (top photo), note the hard shell projecting laterally towards the cyclists thigh muscles (arrow).  Compare this to the Sella SMP design (green saddle below) where the shell curves downwards and offers a large padded guide for the thigh muscles.

The Sella SMP range of saddles generally has a large downward sloping edge of the saddle which minimises the risk of thigh irritation.

In our next blog we’ll consider saddle padding and how it can be used to alter comfort, although you might be surprised to learn that more padding is often more pain not less!