Saddle contact is the most common cause of discomfort among cyclists. The first and most important step to avoid this is to know how to choose the right saddle and how to adjust it.
Image: GT BicyclesThe reason saddle contact is so critical is because the body is not designed to maintain the same posture for hours on end or for so much weight to be supported by such a small contact area, which includes soft tissues as vulnerable and exposed to pressure as nerves or blood vessels. For this reason, it is so important to adopt the correct posture and choose a saddle and technical garments that offer suitable protection. Fortunately, there are excellent materials to choose from and there is an abundant source of information on bicycle biomechanics.
Figure 1: Diagram of the anatomy of a cyclist on the saddle (Specialized Bicycle)Figure 1 shows the pelvis of a cyclist on the saddle. It is formed by the two right and left coxal bones,, the sacrum and the coccyx. The coxal bones have three distinct parts, the upper part is the ilium, the lower is the ischium and the pubis is at the front.
The ischial tuberosities, or sit bones, support your weight when sitting in a normal position. But a different posture is adopted on the saddle and other parts of the hip are involved. The two coxal bones form a triangular shape at the bottom until they meet at the pubic symphysis, which forms the channel where nerves and blood vessels pass to the genitals. When you sit on the bike saddle and tilt your body, the hips rotate forward and the pubic bone pinches these nerves and blood vessels, especially the pudendal artery, which supplies the genital area. This pressure can cause numbness of the genitals, discomfort and, in some cases, serious injury over time. Therefore, when choosing and adjusting a bicycle saddle, it is important that you ensure the sit bones are supporting most of your weight so that pressure on the perineal area is reduced.
Several factors should be taken into account, to avoid saddle problems and to ensure correct adjustment. These are:
In order for the weight to be distributed on the right bones, it is essential that the saddle is wide enough to offer firm support. The most commonly used measurement is the distance between the ischial or sit bones. But there are exceptions, depending on certain activities, such as triathlon or time trials, which involve very forced postures. Once you know the distance of the sit bones, the general recommendation is that the saddle should be at least 20 mm wider to ensure correct support.
Specialized was the first brand to carry out medical research and apply biomechanics to its saddle designs, which resulted in various sizes being manufactured. It also developed the first measuring system which became known as the Ass-O-Meter, to measure the distance between the ischia and recommend saddle size. Most brands now offer different widths and there are several that have other measuring tools, but we will focus on the Specialized system, as this is the most widely used.
Saddle width is measured at the widest part of the saddle from the outer edges. Specialized's measurements are 131, 143, 155, 155, 168 and up to 180 mm for the more recreational saddles. The other brands use similar ranges, with variations of only a few millimetres. The sizes most commonly used by men are 143 and 155 mm. The most frequent widths for women are 155 and 168 mm, which is why women-specific saddles are usually wider, as well as featuring designs that specifically adapt to the female sexual anatomy.
The distance between the ischial bones does not depend on factors such as weight or height. After reaching adulthood, the bone structure does not vary and is specific to each person, regardless of their weight and build. There are no references for estimating the width and each person needs to be measured. In general though, women have wider hips, due to their adaptation to childbirth.
The measuring system involves the cyclist sitting on the Ass-O-Meter, which consists of a soft gel base, and the sit bones leave an impression and this is then measured. The device also includes a chart that indicates the recommended saddle width, according to the measurement obtained. If you do not have access to a measuring device, you can improvise with a mouldable surface, such as cardboard, putty, plasticine, etc., or have someone measure by hand, by feeling the tip of the ischial bones. It is much easier using a measuring device, and these can usually be found at specialised shops.
Specialized Ass-O-MeterFor the measurement to be correct, the posture should be mimic being on a bike; raising the heels slightly, to pronounce pressure on the ischia, as in the photo below.
Correct posture on Ass-O-MeterAfter standing up, the distance between the two impressions is marked on the scale and the colour indicated by the right marker refers to the recommended saddle width on the left.
Measuring the distance between the sit bonesOnce you know your saddle width measurement, you can begin to focus on other factors to find the right one for you. Bear in mind though, that the width measurement can vary depending on the type of bike and rider. The table in figure 2, complements the information provided by the Ass-O-Meter, you can see how different widths are recommended according to the cyclist's posture.
Figure 2: BG Specialized saddle width recommendationThe saddle shape depends on the type of cycling and on the flexibility and anatomical features of the cyclist. Most brands make specific saddles for each type, and the following classification can be very useful for filtering through the huge selection available.
Flat or waved. Viewed from the side, most saddles nowadays are slightly concave with a moderate rise at the back to support the sit bones and relieve pressure on the perineum. Flat saddles promote freedom of movement and are preferred by some cyclists, especially for the faster MTB disciplines.
Flat or curved sides. Viewed from the back, curved sides also offer greater freedom of movement and posture changes, so they are recommended for long duration and for riders with less flexibility. Saddles with flatter sides provide firmer support, which is especially appreciated by more experienced riders who are focusing on performance and tend to have good flexibility.
Antiprostatic saddle. A groove or channel in the centre of the saddle has now become widespread in saddle designs. This channel relieves pressure on the perineal area and the prostate, which in turn, minimises the pressure exerted by the pelvis on the nerves and blood vessels that pass through the pubic symphysis. In general, they serve their purpose and are a good choice, providing you have chosen the proper width and shape of saddle. A saddle that is too narrow and provides poor bone support will not only cause pressure, but the grooves can become even more harmful than a flat saddle. And likewise, a correctly shaped saddle with no groove that offers good ischial support can be perfect for many riders, if it is properly adjusted.
Length and nose shape. A longer or shorter saddle nose provides freedom of movement and contributes to the desired release of pressure for the most delicate part of our support, which is the perineal area. Especially if it is slightly tilted, as we will see in the section on adjustment. The trend is to reduce the nose length and models such as the Specialized Power or the Selle Italia ST are in great demand. More important than the length is the shape. A nose that forms a triangle with a wide base will offer more support, especially for those who ride in a more upright position, but for riders with a more aggressive posture or with large leg volume, a nose that is narrow from the base will provide greater comfort. Duopower was the first brand to do away with the saddle nose completely, but this design is only used by a minority.
Syncros Belcarra V 1.5
Selle Italia ST5 Flow
Fi’zi:k Argo Vento R5Hard or soft. Saddle cushioning depends on the level of experience and on the preference of each cyclist.
The best quality saddles have zones with different densities, depending on the body area and the pressure it is able to withstand. Specialized, once again, is a pioneer in the development of MIMIC technology, first applied to women's saddles, with great success, and later extended to men's models. It consists of manufacturing the saddle that combines soft nose comfort with sufficient structural support, specifically designed to relieve pressure on the genital area, which is especially sensitive in the case of women.
Specialized Power Pro Mimic Elaston SaddleSaddle weight. This is a fundamental aspect for competition or very demanding amateur cyclists, and will be less important for the rest. If you have chosen the right saddle according to the factors mentioned above, the weight will be consistent with the use. But, in any case, our advice is to always give priority to comfort and health, rather than to weight. There are no benefits in a lighter saddle, if the design and size are inadequate, far from it, as the pain and discomfort, especially on long distance or multi-day rides, can turn the trip into a nightmare.
Many aspects influence the choice of the best saddle for each individual and no set of rules or advice can be applied to everyone. Anatomy and biomechanics are not exact sciences. Everything we have explained will serve as a guide to help you choose, but your personal experience will be decisive and sometimes, all you can do is to rely on trial and error. We highly recommend visiting a specialised store that offers test programs, such as Mammoth, where you can try out different types and sizes, and find which one works for you.
Even the best saddle can be useless unless you consider other factors, such as the the correct saddle adjustment and the use of a good pair of cycling shorts, which we will discuss below.
Specialized Power Saddle from Mammoth test programThe correct saddle adjustment is just as important as the right choice of saddle width, type and shape. There is little point in making an exquisite selection when choosing a saddle, if you don't adjust it properly.. On many occasions, the discomfort and pain that cyclists suffer with the saddle is due to a bad adjustment..
Saddle height adjustment. Beginner cyclists tend to set their saddle too low and more experienced cyclists tend to set it too high. Both situations cause discomfort, reduce performance and can lead to injury. But, excessive saddle height is the cause of most discomfort, as it increases pressure and friction. We recommend this video on how to adjust the saddle height correctly:
Saddle setback and tilt. The saddle also needs to be adjusted correctly in the horizontal position with respect to the pedals. A very common mistake is to use the saddle to move closer or further away from the handlebars, causing the incorrect pedalling position. The tilt also needs to be adjusted, depending on the type of bike and, once again, on the individual cyclist.
We highly recommend watching the second instalment on saddle adjustment on our channel:
Due to their particular features, we have dedicated a specific section to Triathlon saddles. In this discipline, cyclists are in an extreme posture to achieve aerodynamic penetration, forcing maximum hip rotation. This means that the weight of the cyclist on the saddle falls on the pelvic bones, rather than on the sit bones, and the perineum suffers greater pressure. In this third instalment of the saddle video series, we give you tips on how to choose the best triathlon saddle:
At our https://www.mammothbikes.com/en/ website and at Mammoth stores, we have saddles for all types of cycling and all rider profiles, and offer a test programme to try out different types and sizes and, of course, the best advice for choosing your saddle, because we are cyclists too.
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