Bicycle saddle
Encyclopedia
Bicycle pedal
A bicycle pedal is the part of a bicycle that the rider pushes with their foot to propel the bicycle. It provides the connection between the cyclist's foot or shoe and the crank allowing the leg to turn the bottom bracket spindle and propel the bicycle's wheels...
and the handlebars
Bicycle handlebar
Bicycle handlebar or often bicycle handlebars refers to the steering mechanism for bicycles; the equivalent of a steering wheel. Besides steering, handlebars also often support a portion of the rider's weight, depending on their riding position, and provide a convenient mounting place for brake...
.
The bicycle saddle has been known as such since the bicycle
Bicycle
A bicycle, also known as a bike, pushbike or cycle, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist, or bicyclist....
evolved from the draisine
Draisine
A draisine primarily refers to a light auxiliary rail vehicle, driven by service personnel, equipped to transport crew and material necessary for the maintenance of railway infrastructure....
, a forerunner of the bicycle. It performs a similar role as a horse's saddle
Saddle
A saddle is a supportive structure for a rider or other load, fastened to an animal's back by a girth. The most common type is the equestrian saddle designed for a horse, but specialized saddles have been created for camels and other creatures...
, not bearing all the weight of the rider as the other contact points also take some of the load.
A bicycle saddle is commonly attached to the seatpost
Seatpost
A bicycle seatpost, seatpin, saddlepole, saddle pillar, or saddle pin is a tube that extends upwards from the bicycle frame to the saddle. The amount that it extends out of the frame can usually be adjusted, and there is usually a mark that indicates the minimum insertion...
and the height of the saddle can usually be adjusted by the seatpost telescoping in and out of the seat tube.
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.Most modern saddles have a hard shell made from a moulded piece of plastic, such as nylon
Nylon
Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...
. Carbon fiber may also be used.
Leather
Leather
Leather is a durable and flexible material created via the tanning of putrescible animal rawhide and skin, primarily cattlehide. It can be produced through different manufacturing processes, ranging from cottage industry to heavy industry.-Forms:...
saddles do not have a hard shell. Instead a moulded piece of thick leather is stretched, like a taut hammock
Hammock
A hammock is a sling made of fabric, rope, or netting, suspended between two points, used for swinging, sleeping, or resting. It normally consists of one or more cloth panels, or a woven network of twine or thin rope stretched with ropes between two firm anchor points such as trees or posts....
, between the front and rear ends of the rails. Traditional leather saddles such as those made by Brooks
Brooks England
Brooks England is a bicycle saddle manufacturer in Smethwick, Birmingham, England. It has been making leather bicycle saddles since 1866, when it was founded in Hockley, Birmingham....
have been used for many years. Such a saddle is generally more comfortable after a break-in period during which it conforms to the shape of the rider, so long as the basic shape is right to start with.
Cover
Most saddles use some form of padding on top of the hard shell (often closed cell foam, gel, or gel-foam) followed by a outer cover consisting of Lycra, vinylVinyl
A vinyl compound is any organic compound that contains a vinyl group ,which are derivatives of ethene, CH2=CH2, with one hydrogen atom replaced with some other group...
, artificial leather, or leather
Leather
Leather is a durable and flexible material created via the tanning of putrescible animal rawhide and skin, primarily cattlehide. It can be produced through different manufacturing processes, ranging from cottage industry to heavy industry.-Forms:...
.
Saddles designed for hard use e.g. mountain bike
Mountain bike
A mountain bike or mountain bicycle is a bicycle created for off-road cycling. This activity includes traversing of rocks and washouts, and steep declines,...
or BMX
BMX
Bicycle motocross or BMX refers to the sport in which the main goal is extreme racing on bicycles in motocross style on tracks with inline start and expressive obstacles, and it is also the term that refers to the bicycle itself that is designed for dirt and motocross cycling.- History :BMX started...
style riding, may have additional cover reinforcements such as kevlar
Kevlar
Kevlar is the registered trademark for a para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed at DuPont in 1965, this high strength material was first commercially used in the early 1970s as a replacement for steel in racing tires...
sewn to the cover to withstand abrasion on those areas most prone to abrasion.
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. Most saddles have two parallel rails that the seatpostSeatpost
A bicycle seatpost, seatpin, saddlepole, saddle pillar, or saddle pin is a tube that extends upwards from the bicycle frame to the saddle. The amount that it extends out of the frame can usually be adjusted, and there is usually a mark that indicates the minimum insertion...
clamps to. They provide fore and aft adjustment of the saddle, usually an inch or so (2.5 cm). Rails can be made of steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
, titanium
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....
, aluminum, magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
, or carbon fiber
Carbon fiber
Carbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber...
. Rails may be solid or hollow.
Saddle rails are typically a 7 millimeter diameter, an industry standard for some time. Today some companies are introducing saddles that use carbon fiber rails that have a larger diameter or even an oval shape requiring use of a seatpost specifically designed for the particular rail diameter and/or shape.
A recent innovation, used with carbon shells and rails, is for the rails to be integrated into the shell for their entire length. Another is an interface called pivotal. Pivotal seatpost
Seatpost
A bicycle seatpost, seatpin, saddlepole, saddle pillar, or saddle pin is a tube that extends upwards from the bicycle frame to the saddle. The amount that it extends out of the frame can usually be adjusted, and there is usually a mark that indicates the minimum insertion...
s are common on BMX
BMX
Bicycle motocross or BMX refers to the sport in which the main goal is extreme racing on bicycles in motocross style on tracks with inline start and expressive obstacles, and it is also the term that refers to the bicycle itself that is designed for dirt and motocross cycling.- History :BMX started...
bikes. They have a concave semicircle of ridges at their top that matches the convex semicircle of ridges on the bottom of a pivotal saddle. The two semicircles are held together with a bolt to attach the saddle to the seatpost. A recent rail type is the i-beam; it extends along much of the saddle's length and uses two clamping bolts. Because the beam is long and the clamp narrow, the i-beam mounting affords a wide fore-aft adjustment range; the saddle clamp however, is of a unique type.
Suspension
A saddle may contain one or more suspension components to improve rider comfort by absorbing or deadening vibration and shock transmitted by the frame and seatpost.Saddles may incorporate gel, gel-foam, and/or multiple-density foam padding or lining to cushion impacts from the roadway, while integrated saddle rails may be designed with added length in order to flex vertically, providing limited shock and bump absorption.
Another method encountered on recreational, comfort, or 'cruiser' saddles is to attach a pair of steel coil springs to the rear terminus of the saddle rails, affixed at their other end to the rear of the saddle. Some newer suspension designs replace the twin coil springs with four or more elastomer
Elastomer
An elastomer is a polymer with the property of viscoelasticity , generally having notably low Young's modulus and high yield strain compared with other materials. The term, which is derived from elastic polymer, is often used interchangeably with the term rubber, although the latter is preferred...
donut-type springs. By using interchangeable elastomers with variable densities the suspension saddle can be tuned to the rider's weight and riding style.
Yet another method of suspension utilizes a web-spring platform made of eight or more coil springs mounted horizontally beneath the saddle shell. These springs are connected to each other at the approximate center of the saddle, with the ends connected radially to the perimeter of the saddle frame, forming a spider's web. A shock transmitted to the seat is partially absorbed by this web-spring platform. In an effort to cut cost and weight, some suspension saddles utilize a skeletonized, flexible nylon frame in lieu of the steel web-spring.
Saddles may incorporate two or more of these suspension designs in an effort to provide additional comfort and shock absorption.
Adjustment
The position of the saddle should be adjusted relative to the bottom bracketBottom bracket
The bottom bracket on a bicycle connects the crankset to the bicycle and allows the crankset to rotate freely. It contains a spindle that the crankset attaches to, and the bearings that allow the spindle and cranks to rotate. The chainrings and pedals attach to the cranks...
, 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. 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 center 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.
Height
The saddle height should be set so that when pedaling, 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, on bikes with traditional geometry, the rider cannot place both feet flat on the ground when seated on the saddle. If they can, their saddle is too low, unless the bike is a recumbentRecumbent bicycle
A recumbent bicycle is a bicycle that places the rider in a laid-back reclining position. Most recumbent riders choose this type of design for ergonomic reasons; the rider's weight is distributed comfortably over a larger area, supported by back and buttocks...
or other crank-forward design.
Tilt
The saddle should be nearly level, although the height of the handlebars and style of cycling will cause this to vary.Fore and aft
Conventional wisdom dictates that the saddle should be positioned so that when the crankarmsCrankset
The crankset or chainset , is the component of a bicycle drivetrain that converts the reciprocating motion of the rider's legs into rotational motion used to drive the chain, which in turn drives the rear wheel...
are horizontal and the feet are on the pedals the head of fibula
Head of fibula
The upper extremity or head of the fibula is of an irregular quadrate form, presenting above a flattened articular surface, directed upward, forward, and medialward, for articulation with a corresponding surface on the lateral condyle of the tibia....
of the forward leg is approximately above the pedal spindle
Bicycle pedal
A bicycle pedal is the part of a bicycle that the rider pushes with their foot to propel the bicycle. It provides the connection between the cyclist's foot or shoe and the crank allowing the leg to turn the bottom bracket spindle and propel the bicycle's wheels...
in a vertical line. However, several authors argue that there is no anatomical basis for this. Furthermore, the relative position of saddle and bottom bracket
Bottom bracket
The bottom bracket on a bicycle connects the crankset to the bicycle and allows the crankset to rotate freely. It contains a spindle that the crankset attaches to, and the bearings that allow the spindle and cranks to rotate. The chainrings and pedals attach to the cranks...
varies between road racing
Racing bicycle
A racing bicycle, also known as a road bike, is a bicycle designed for competitive road cycling, a sport governed by according to the rules of the Union Cycliste Internationale...
, track
Track bicycle
A track bicycle or track bike is a bicycle optimized for racing at a velodrome or outdoor track. Unlike road bicycles, the track bike is a fixed-gear bicycle and so has a single gear and neither freewheel nor brakes. Tires are narrow and inflated to high pressure to reduce rolling resistance...
and triathlon bicycles.
The range of adjustment differs for each saddle, and the comparison of saddles for increased ranges of adjustment can be confusing owing to their different shapes. In comparing them, it is the range of adjustment of their comfort points that need considered, and because the matter is largely subjective, giving it proper attention is difficult to do. The range of fore-aft adjustment for double-rail saddles rarely exceeds an inch or so, but advertisers claim that i-beam saddle designs can give up to 200% more adjustment range than some of these.
When the fore-aft adjustment range of the saddle needs further extension than the clamp affords, it may be possible to add a saddle adjuster. One such adjuster mounts on the existing saddle clamp and allows up to 40mm of increase or decrease in the fore-aft position of the saddle. Another method for increasing the fore-aft adjustment is the swept-back seat post, where the seat post has a curve in it over the six inches or so before the saddle. Because of the gentle sweep of the tube, the top part of the seat-post cannot fit within the seat-tube, so this solution is useful only for high seat positions.
Sizes
While small saddles are available for children's bikes, the primary size parameter for adult saddles is width. Performance saddles, such as for racingBicycle racing
Bicycle racing is a competition sport in which various types of bicycles are used. There are several categories of bicycle racing including road bicycle racing, cyclo-cross, mountain bike racing, track cycling, BMX, bike trials, and cycle speedway. Bicycle racing is recognised as an Olympic sport...
, tend to be narrow. Comfort saddles, often found on hybrid bicycle
Hybrid bicycle
A hybrid bicycle is a bicycle designed for general-purpose utility and commuting on a wide variety of surfaces, including paved and unpaved roads, paths and trails...
s, tend to be wide.
Variations
Several variations have been developed, either for aestheticAesthetics
Aesthetics is a branch of philosophy dealing with the nature of beauty, art, and taste, and with the creation and appreciation of beauty. It is more scientifically defined as the study of sensory or sensori-emotional values, sometimes called judgments of sentiment and taste...
reasons, or to address issues mentioned in the next section.
A banana seat is a long saddle, usually supported at both ends, popular on wheelie bike
Wheelie bike
A wheelie bike, also called a muscle bike, high-riser, or banana bike, is a type of stylized children's bicycle designed in the 1960s to resemble a chopper motorcycle and characterized by ape hanger handlebars, a banana seat with sissy bar, and small wheels. Notable examples include the Schwinn...
s.
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.
While not adopted by competitive cyclists, no-nose saddles have been shown to improve erectile function among cyclists suffering from ED. A 2008 study measured ED and genital numbness among bicycling police
Police
The police is a personification of the state designated to put in practice the enforced law, protect property and reduce civil disorder in civilian matters. Their powers include the legitimized use of force...
officers who used traditional saddles versus the same officers after using no-nose saddles for six months. The number of officers experiencing genital numbness fell from 73% to 12%. Cases of erectile dysfunction also fell significantly. This research won the Bullard Sherwood Award of the National Institute for Occupational Safety and Health
National Institute for Occupational Safety and Health
The National Institute for Occupational Safety and Health is the United States’ federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness. NIOSH is part of the Centers for Disease Control and Prevention within the U.S...
, for intervention research. However, some authorities say this type of seat causes more problems than it cures.
Issues
Several issues associated with sitting on traditional bicycle saddles have been identified.Crotch pressure
Though riding an upright bicycle improves the cardiovascular systemCirculatory system
The circulatory system is an organ system that passes nutrients , gases, hormones, blood cells, etc...
and can therefore actually improve the erectile function among men, riding a bicycle for prolonged periods of time with an unhealthy cycling technique can still cause problems for both men and women due to a reduced blood flow
Blood flow
Blood flow is the continuous running of blood in the cardiovascular system.The human body is made up of several processes all carrying out various functions. We have the gastrointestinal system which aids the digestion and the absorption of food...
in the crotch
Crotch
The term crotch may be used to describe the region of an object where it splits into two or more limbs. This can include trees, animals, buildings, in wiring diagrams, etc....
area. Some male riders — recent survey data indicates around 5% — may ultimately get erectile dysfunction
Erectile dysfunction
Erectile dysfunction is sexual dysfunction characterized by the inability to develop or maintain an erection of the penis during sexual performance....
problems if a poor cycling technique is used with prolonged pressure on the perineum
Perineum
In human anatomy, the perineum is a region of the body including the perineal body and surrounding structures...
. 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
Buttocks
The buttocks are two rounded portions of the anatomy, located on the posterior of the pelvic region of apes and humans, and many other bipeds or quadrupeds, and comprise a layer of fat superimposed on the gluteus maximus and gluteus medius muscles. Physiologically, the buttocks enable weight to...
. Such saddles achieve a similar relief of pressure by using a different design.
Some useful techniques to reduce crotch pressure while cycling include:
- Ensuring the 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 boneTuberosity of the ischium-External links: - "The Female Perineum: Bones" - "Major Joints of the Lower Extremity: Hip bone "...
support of the pelvis, again resulting in an increased perineum pressure. - Standing up occasionally, such as on hills and when accelerating.
- Adjusting seating position from time to time. For example, sitting closer to the rear when cycling on hills and only sitting on the nose for brief periods.
- Sitting up now and then without leaning forward as much.
Erectile dysfunction and genital numbness
Bicycle riding has been correlated with genital numbness, erectile dysfunctionErectile dysfunction
Erectile dysfunction is sexual dysfunction characterized by the inability to develop or maintain an erection of the penis during sexual performance....
(ED) and perianal hematoma
Perianal hematoma
A perianal hematoma is a type of hematoma located in, or on the border of the anus. It can be misdiagnosed as a hemorrhoid, but is sometimes referred to as an external hemorrhoid.-Causes:...
, and several studies have shown that long-distance cyclists have an increased incidence of ED as compared to the general population. ED and genital numbness result from compression of the cyclists' perineal region
Perineum
In human anatomy, the perineum is a region of the body including the perineal body and surrounding structures...
while sitting on their saddles. To alleviate the problem, manufacturers have designed a number of bicycle saddles that purport to allow greater blood flow through the pudendal artery. These saddles vary in shape, width, and padding and have been studied to determine any actual effects on cyclists' health. (However, most current research excludes discussion of female sexual dysfunction and genital numbness.)
The studies have shown that wider saddles tend to increase penile blood flow while cycling, though wider seats also induce chafing
Chafing
Chafing when used as a nautical term describes the process of wear on a line or sail caused by constant rubbing against a hard, usually metallic, surface. Various methods are used to prevent chafing. Chafing of lines that rest on a choke on a boat can be prevented by putting a protecting material...
and impede a cyclist’s full range of leg motion. A downward-tilted saddle relieves pressure on the perineum and the "sit bones" (ischial tuberosities
Tuberosity of the ischium
-External links: - "The Female Perineum: Bones" - "Major Joints of the Lower Extremity: Hip bone "...
), thus improving a cyclist's perineal blood flow. Most saddles include padding, generally foam
Foam
-Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...
or gel
Gel
A gel is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state...
. Gel padding tends to distribute pressure in the perineum and provide higher levels of penile oxygenation than does foam padding. However, width and design have proved to be more important than the amount of saddle padding in determining the intensity of perineal distress the cyclist suffers. In fact, some researchers have postulated that extra padding, foam or gel, can result in an increased prevalence of pain in the sit bones.