Bicycle saddle

From Wikipedia, the free encyclopedia

A bicycle saddle is one of three contact points on a upright bicycle, the others being the pedals and the handlebars. The bicycle saddle is known as such since the bicycle evolved from a device which looked like a wooden horse on wheels. A bicycle saddle is commonly attached to the seat post and the height of the saddle can usually be adjusted by the seat post telescoping in and out of the seat tube.

Contents 1 Components 1.1 Shell 1.1.1 Hard shell 1.1.2 Leather 1.2 Cover 1.3 Rails 1.4 Suspension 2 Adjustment 2.1 Height 2.2 Tilt 2.3 Fore and aft 3 Sizes 4 Crotch pressure 5 Extra padding 6 References 7 External links

[edit] Components

Typical saddles are composed of a few identifiable components.

[edit] Shell

The shell creates the shape of the saddle. The nose of the saddle is the forward most part. It is usually rounded. The shell can be made from several materials.

[edit] Hard shell

Most modern bicycles have a saddle that has a shell made from a moulded piece of plastic, such as nylon. Carbon fiber may also be used. ^[1]

[edit] Leather

Leather saddles do not have a hard shell. Instead a moulded piece of thick leather is stretched, like a taut hammock, between the front and rear ends of the rails. Traditional leather saddles such as those made by Brooks have been used for many years. Such a saddle is generally comfortable after a break-in period during which it conforms to the shape of the rider.^[2]

[edit] Cover

There is usually, but not always, some form of padding on top of the hard shell, often closed cell foam or gel, and then a fabric, such as lycra, vinyl, artificial leather, or leather cover.

Some saddles, especially those designed for hard use e.g. mountain bike or BMX style riding, will have a tougher material, such as kevlar, to withstand abrasion on the nose and the widest parts of the rear.

[edit] Rails

The rails of a saddle are the connection point to the rest of the bike. They run along the underside of the saddle from the nose to the rear. The seatpost clamps to the two rails. They provide fore and aft adjustment of the saddle, usually an inch or so (2.54 cm). Rails can be made of steel, titanium, magnesium, or carbon fiber. Rails may be solid or hollow.

While many interface standards on bicycles continue to evolve (seatpost diameter, crankarm spline, etc.) the seat rail size and spacing has remained constant so far. Nearly any saddle can be mounted to any seatpost. A recent innovation, used with carbon shells and rails, is for the rails to be integrated into the shell for their entire length.

[edit] Suspension

A saddle may contain suspension components, such as springs or elastomers between the rails and the shell, to help absorb vibrations transmitted by the frame and seatpost.

By using interchangeable elastomers with variable densities the suspension saddle can be tuned to the rider's weight and riding style. ^[3]

[edit] Adjustment

The position of the saddle should be adjusted relative to the bottom bracket, not to the ground or handlebars. For example, if the reach to the handlebars is too far, it is better to get a shorter stem than to move the saddle forward of its ideal location.^[4] More accurately, saddle height should be adjusted relative to the position of the pedals as fitting different pedals or different length cranks would also mean the saddle needs to be re-adjusted. In practice, the distance from the top of the saddle to the centre of the bottom bracket is used as the saddle height, e.g., setting up a new bicycle using measurements from another, as this is easier to measure. Other methods and calculations are used for determining seat height, such as LeMond's formula.

[edit] Height

The saddle height should be set so that when pedalling, the legs have a slight bend even when the pedals are at their furthest distance. This means that if the saddle height is properly adjusted the rider cannot place both feet flat on the ground when seated on the saddle. If he can do so, his saddle is too low.

[edit] Tilt

The saddle should be nearly level, although the height of the handlebars and style of cycling will cause this to vary. A common mistake made by people suffering from crotch-area, hand or arm pain is to tilt the nose down. This is not recommended, as the saddle will then act as a ramp, and the "sit bones" will tend to slide down, and thus forward, placing more pressure on the hands. Pressure should be distributed evenly throughout both sit bones and crotch bone, and this is usually obtained with the saddle at least horizontal, if not slightly "nose up" from horizontal.

[edit] Fore and aft

The saddle should be positioned so that when the crankarms are horizontal and the feet are on the pedals the kneecap of the forward leg is approximately above the pedal spindle in a vertical line.

[edit] Sizes

While small saddles are available for children's bikes, the primary size parameter for adult saddles is width. Performance saddles, such as for racing, tend to be narrow. Comfort saddles, often found on hybrid bicycles, tend to be wide.

Women-specific saddles have been recently introduced by several manufacturers. These incorporate a variety of differences designed to suit female anatomy. These differences may include a wider seat area, shorter nose, and center relief.^[5]

[edit] Crotch pressure

While riding an upright bicycle improves the cardiovascular system and can therefore actually improve the erectile function among men, riding a bicycle for prolonged periods of time with a poor cycling technique can still cause problems for both men and women due to a reduced blood flow in the crotch area. Some men — recent survey data indicates around 5%^[6] — may ultimately get erectile dysfunction problems if a poor cycling technique is used with prolonged pressure on the perineum. Both men and women may also get reduced sensitivity in the crotch. A sign of these problems can sometimes be a tingling sensation in the area when stepping off the bicycle after a ride, as blood flow surges back into the area again. This issue is more related to the cycling technique than the saddle type, although there are special, more anatomically correct, designs to relieve crotch pressure as well. Examples of such designs include the cutaway saddles and noseless saddles. Cutaway saddles resemble regular saddles in their design, but with the middle part cut out to reduce pressure on the perineum among men. Noseless saddles are basically two separate saddles next to each other, with one smaller "saddle" per buttock. Such saddles achieve a similar relief of pressure by using a different design.

Some useful techniques to reduce crotch pressure while cycling include:

• Ensure your saddle is roughly horizontally aligned, or only slightly nose up. The nose too upwards aligned will directly increase the perineum pressure, while a downwards alignment will reduce the sit bone support of your pelvis, again resulting in an increased perineum pressure.
• Make it a habit to stand up occasionally, such as on hills and when accelerating if you have stopped cycling or slowed down.
• Adjust how you sit from time to time. For example, try to sit closer to the rear when cycling on hills and only sit on the nose for brief periods.
• Try to sit up now and then without leaning forward as much.

[edit] Extra padding

Additional padding is commercially available in the form of covers that can be placed over a saddle to improve comfort, however this may have the opposite effect. The hard bone which supports the rider will push down into the gel seat, causing the gel to apply pressure on more sensitive parts of the anatomy. Gel padding is mostly marketing hype, since they do little to make cycling more comfortable, if not make it worse.

An uncomfortable seat, therefore, may be due to too much padding, or not enough support in the right areas, and gel padding should not be considered. Proper fitting by a local bike shop is the best way to achieve comfort.

Most people should ride regularly for at least two months before deciding that a saddle needs to be replaced. Unless the same bicycle with the same saddle is ridden regularly for at least two months, one can not expect to be comfortable on any saddle.

[edit] References

[edit] External links

• Elements of Comfort - Bicycle Saddle Technology by Koobi
• Cycling performance tips: choosing and adjusting your saddle
• Bicycle saddles and comfort
• Saddle seats and erectile dysfunction: the myth exploded
• "Bicycling, saddles, impotence... What we think about it all!"
• A Comfortable Saddle by Sheldon "Comfort" Brown