All the best, Sheldon
Everybody wants a comfortable saddle on their bicycle. What is not so obvious is what constitutes a comfortable saddle.
Every spring, bike shops sell scads of saddles to cyclists who come in because their old saddle has become uncomfortable since they stopped cycling in the fall. They went out for a ride or two, and found it much less comfortable than they remembered from the previous year. They've heard about the latest buzzword in saddle gimmicks, and they want one of those!
They buy the new saddle, put it on the bike, go for a few more rides, and find they're much more comfortable. They tell all their friends about their wonderful new saddle, and how they need one too...
But was it really the new, high-tech saddle...or was it just that the rider had become unaccustomed to cycling over the winter layoff? In many cases, working your way up over the course of a few short rides of gradually increasing length is all that is necessary, if you have a decent-quality saddle, properly adjusted. If you have previously been comfortable on your present saddle, don't be in a hurry to change.
You'll notice that I do call them "saddles," not "seats." There is a reason for this. A "seat" is something you sit on, and is designed to bear essentially your entire weight. Recumbent bicycles have "seats," but conventional upright bicycles have saddles. A saddle is intended to carry some, but not all of your weight. The rest of your weight is mainly carried by your legs, and some by your hands and arms.
A cyclist who is out of cycling shape, from being off a bicycle for a few months or more, will start out strong, but the legs will tire rapidly. When the legs tire, the rider sits harder on the saddle, and that's when the trouble starts. Many saddle complaints are actually traceable to fatigue caused by starting out the season with a longer ride than you are ready for.
This is not to say that there are not real differences in saddles, nor that you should ride just anything. In fact, original equipment saddles that come with bikes are often greatly inferior to better aftermarket saddles.
When a cyclist finds a saddle uncomfortable, the first impulse is often to look for a soft one. This is often a mistake. Just as the softest mattress is not necessarily the most comfortable to sleep on, the softest saddle is not the most comfortable to cycle on.
The "Two Bump Problem"Imagine sitting down on a coffee table. Your weight is concentrated on the two bumps of your "sit bones", also known as the "ischial tuberosities." These are the parts of your body designed to bear your seated weight. Most cases of saddle-related discomfort arise because the load is carried on the soft tissues between the sit bones.
Imagine placing a soft pillow on top of the coffee table. Now, as you sit down on it, the sit bones compress the pillow, which yields until the sit bones are almost on the table surface again. The difference is that now, you have pressure in between your sit bones from the middle part of the pillow.
Many cyclists are unaware of this, and many saddles are made to appeal to the purchaser who chooses a saddle on the basis of how easily the thumb can sink into the squishy top. This type of saddle is only comfortable for very short rides, (though an inexperienced cyclist will often find it more comfortable than a better saddle, as long as rides don't exceed a mile or two.)
Saddles with excessive padding are also a common cause of painful chafing of the inner thigh, as rides become longer.
The width of a saddle is quite crucial to the rider's comfort, and should be related to the space between the rider's sit bones. If the saddle is too narrow, the sit bones will hang over the sides, and the soft tissues will bear the load. If the saddle is too wide, it is likely to cause chafing of the inner thigh, especially in hot weather.
Many of the symptoms of mismatched saddle width are related to improper adjustment, so you should not necessarily discard your saddle as a bad fit if you haven't first experimented with its position.
A common buzzword in saddle construction is "gel", which is often touted as a cure-all. The material known as "gel" is a particular type of closed-cell foam, in which the air bubbles are at higher than normal pressure. The fact that a given saddle says "GEL" in big letters has no correlation with how comfortable it is...it's basically hype.
There are two fundamental types of saddle construction in current use: padded plastic or stretched leather.
The typical modern saddle consists of four parts, the frame, the base, the padding and the cover:
- The metal frame, usually made of a steel or titanium rod, shaped as the letter "V" with the point forward.
- The plastic base of the saddle attaches to the frame at three points. The base may be made of hard or flexible plastic. Better bases are designed to flex under the rider's weight, and often are made to be thinner under the sit bones to make them more shock absorbent.
A current trend is to put a large hole in the middle of the base in an attempt to reduce pressure on the genitals or prostate. In some cases, the cover and padding cover this hole, in others the hole runs all the way through, so the saddle is shaped like a triangular doughnut.
This works for some people, but not for others, because the edges of the hole are a bit sharp and can concentrate the load in the groin area.
The base must fit the particular rider's anatomy, and there is a considerable variation among individuals. This means that a saddle that is comfortable for one rider may be a torture for another.
- The padding is usually made of closed-cell foam, sometimes of the "gel" variety. If it is too soft or too thick it can cause problems, either by exerting pressure on the soft tissues, or by causing chafing.
- The cover, which should be smooth but not too slippery, yielding, but not too fragile, and, if possible, should "breathe" a bit may be:
- Leather, which is used on the better saddles, and has all of the desired qualities
- Lycra ®, which is slippery and breathable, but sometimes too slippery, and is rather fragile. The better Lycra ® covered saddles often have plastic re-inforcements at the points most exposded to damage (the 3 corners.)
- Vinyl, or vinyl-covered cloth, usually textured to approximate the appearnce and consistency of leather. Vinyl tends to be a bit slipperier, and to breathe poorly. It is more durable than Lycra ®, and cheaper than leather.
Until the mid 1970s, most good quality bicycles came with tensioned leather saddles. These have a frame basically similar to that of the padded plastic saddle, but with a curved metal bridge connecting the two rear points of the "V". A thick piece of leather is rivetted to this bridge, and to an adjustable fitting at the nose of the saddle. The leather is suspended sort of like a hammock.
A properly shaped leather saddle is an excellent choice for the high-mileage rider who doesn't mind the fact that it is a bit heavier than a plastic saddle.
Leather saddles provide "give" by stretching and flexing, without the need for foam padding. The lack of foam greatly improves comfort in hot weather, as heat and perspiration can "breathe" through the porous leather.
Leather saddles also "break in" to fit the particular shape of the rider, in much the same way as a baseball glove does.
They do require more care than plastic saddles. For more on this topic, see my article on Leather Saddles.
There are many aftermarket pads/covers available to put on top of your saddle. Most of these are not worthwhile. If your saddle is uncomfortable, it is very unlikely that any possible add-on device will make it comfortable. If the saddle is the wrong shape to fit your body, no accessory can correct this problem; bite the bullet, and buy a new saddle instead.
Saddle position may be adjusted in three different ways, all of which are important:
HeightThe most basic saddle adjustment is the height. Most bicyclists have their saddles too low, so that their knees are excessively bent as they pedal. This makes cycling much more tiring for a given speed, and is likely to cause harm to the knees.
A common reason for keeping the saddle set too low is that most bicyclists have never learned the proper technique for mounting and dismounting, so they find it convenient to be able to put a foot down to steady the bicycle while they are stopped. With older bicycles, it was sometimes possible to put a toe down at a stop with the saddle properly adjusted, especially for riders with large feet. Due to the higher bottom brackets common on newer bicycles, especially mountain bikes, it is no longer possible to do this. If you ride a mountain bike, and are able to balance it while stopped and seated, it is a sure sign that your saddle is too low. This is also true of most hybrids.
Having the saddle too low makes it harder to carry much of your weight on your legs, so you will sit with more weight on the saddle. This, in itself, is likely to increase saddle discomfort.
How High?There are lots of formulas for saddle height, most based on multiplying leg length by some fudge factor. The numerical exercise to 3 decimal places gives the illusion of scientific rigor, but, in my opinion, these systems are oversimplification of a problem which involves not only leg length, but foot length, what part of the foot fits on the pedal, shoe sole thickness, type of pedal system and pedaling style.
You cannot judge the saddle height to any accuracy by just sitting on it, or riding around the block. As you get close to the correct position, the clues get more and more subtle.
Most people start with the saddle too low. This is a habit left over from childhood, because growing children almost always have their saddles too low for efficient pedaling. First they have it low for security while they are learning to balance, then, even once they have mastered balancing, their growth rate tends to keep them ahead of their saddle adjustment.
If you always ride with your saddle too low, you get used to it, and don't realize that there is a problem...but there is. Riding with the saddle too low is like walking with your knees bent (as Groucho Marx often did for comedic effect.) If you walked that way all the time, you'd also get used to that, but you'd think that half a mile was a long walk. The way the human leg is made, it is strongest when it is nearly straight.
I like to think that William Blake summed it up nicely 200 years ago when he said:I suggest gradually raising your saddle, perhaps half an inch (1 cm) at a time. Each time you raise it, ride the bike. If it doesn't feel noticeably worse to ride, ride it for at least a couple of miles/km."You never know what is enough
until you know what is too much."
If it had been too low before, your bike will feel lighter and faster with the new riding position. If raising the saddle improved things, raise it again, and ride it some more. Keep doing this until you reach the point where the saddle is finally too high, then lower it just a bit.
When the saddle is too high, you'll have to rock your hips to pedal, and you'll probably feel as if you need to stretch your legs to reach the bottom part of the pedal. Another indication that the saddle may be too high is if you find yourself moving forward so that you are sitting on the narrow front part of the saddle. (Although this symptom can also result from having the saddle nosed down, or having an excessive reach to the handlebars.)
It also makes a bit of difference what sort of pedals/shoes you use. If you ride with ordinary shoes, virtually all of your pedaling power is generated by the downstroke, so a good leg extension is essential to let you apply maximum power in this direction. If you use clipless pedals and cleated cycling shoes, however, you can also generate a fair amount of your power by pulling the pedal backward near the bottom of the stroke. This action also uses the large muscles in the back of the leg, and can be quite efficient. If you make use of this pedaling style, you'll want a slightly lower saddle position than for direct "piston-style" pedaling with street shoes. A slightly lower saddle position is also conducive to pedaling a rapid cadence.
Nuts & BoltsThe saddle is mounted on a seat post, which telescopes into the seat tube of the bicycle frame. The seat tube usually has a gap, which is held together by the seat-post binder bolt. The binder bolt may require a fixed wrench, typically 13 mm or 14 mm; or, it may require an Allen wrench as shown, usually a 5 mm , sometimes a 6 mm; or it may be a quick-release, requiring no tools at all.
To adjust the saddle height, you need to loosen the binder bolt and raise or lower the seat post in the seat tube. It may be necessary to twist it a bit to get it to move. If it is hard to move, you may need to remove it and grease the inside of the seat tube. (If it is really stuck, see my article on Stuck Seatposts.)
There is usually a "minimum insertion" mark about 2 inches (5 cm) from the bottom of the post, to remind you to leave enough post inside the seat tube for security. If in doubt, pull it all the way out and check the length. If you can't get it up high enough without going past the minimum-insertion mark, you should buy a new, longer seatpost. (You'll need to get one the same diameter...bring the old one into the shop for reference.)
If the binder bolt was hard to turn, take it apart and put some oil or grease on the threads, then re-assemble it...this will let you get it tighter, with less risk of stripping the threads.
AngleThe angle of the saddle should be pretty close to horizontal. Some men prefer the front to be slightly higher than the rear; some women prefer the front slightly lower than the rear, but extreme angles should be avoided.
If the saddle is nosed up too far, it is likely to increase pressure on the soft tissues, and cause all sorts of problems.
If the saddle is tilted down in front, the rider will tend to slide forward onto the narrower part of the saddle. Women who are riding on saddles that were designed for men frequently tilt their saddles down. This will relieve some of the discomfort from the saddle itself, but creates new problems: The downward slope of the saddle causes the rider to tend to slide forward, and this can only be counteracted by pressure on the hands. Thus, poorly-angled saddles often are the cause of wrist, shoulder and neck problems, due to carrying too much of the rider's weight on the hands.
The angle and the front-back position are both adjusted by the clamp on the seatpost.
Front-back positionSaddles are also adjustable back and forth. Ideally, this adjustment should be made to set the saddle at the correct distance behind the bottom bracket, so that you are pedaling at an efficient angle. The conventional wisdom is that, when the pedal cranks are horizontal, you knee cap should be directly above the pedal spindle. See Keith Bontrager's article on this topic.
It is generally considered a Bad Idea to tinker with saddle position to adjust the reach to the handlebars; it is better to adjust this by replacing the handlebar stem with one with a different reach, or by buying a bicycle with a different length top tube.
The angle and the front-back position are both adjusted by the clamp on the seatpost.
The saddle is attached to the seatpost by a clamp, which falls into one of two types:
Older (and cheap newer) bicycles use seatposts that are basically a length or steel or aluminum pipe, which narrows down at the top. A separate saddle clamp fits on to the narrow (usualy 7/8"/22.2 mm) section of the seatpost. There is a bolt running crosswise through the clamp, which holds a set of special-shaped washers to the rails of the saddle's undercarriage. When one of the nuts on this bolt is loosened, it becomes possible to slide the rails back and forth and to adjust the tilt of the saddle.
Some of these special washers have serrations which help maintain the angle of the saddle. It is very important to tighten the nuts securely so the saddle will not act as a rocking chair. If it does slip, the serrations will get worn down, and you will be unable to secure the saddle without buying a new saddle clamp.
Most newer bicycles use seatposts which have the saddle clamp built on to the post, which secures the saddle by one or two bolts.
- Single-bolt seatposts use a single vertical bolt to hold the saddle rails sandwiched between a pair of grooved blocks. The lower block will have a curved, serrated surface that mates with a matching curved, serrated surface that is part of the seatpost. When the bolt is loose, the blocks may be tilted to adjust the saddle tilt, and the rails can slide back and forth to adjust the front/rear position of the saddle.
- Two-bolts seatposts use a pair of bolts to hold the blocks of the saddle clamp. Loosening either one of these allows you to slide the saddle back and forth. Loosening one and tightening the other allows you to adjust the tilt. (If one of the bolts is larger than the other, the larger one should be loosened before making any adjustment to the smaller one.) This type of mechanism allows a finer level of control of the saddle tilt, because it doesn't rely on the meshing of teeth in serrated parts, so this type of seatpost is also known as a "microadjust" seatpost. (Single-bolt seatposts are also sometims called "microadjust," with questionable accuracy.)
Much saddle-related discomfort is caused by impacts of the bicycle's wheels with bumps and irregularities in the road. This can be greatly reduced by the use of some form of suspension.
The most basic suspension device is the rider's legs! Experienced cyclists learn to raise themselves slightly off the saddle when riding over major bumps, keeping the knees bent, so that the leg muscles act as springs.
On longer rides, when your legs are tired, this becomes harder to do. Sometimes, too, a bump will take you by surprise. For these situations, a mechanical form of suspension can be helpful.
Until the 1970s bike boom, virtually all bicycle saddles had springs. The only cyclists who rode un-sprung saddles were hard-core, high-intensity riders. These cyclists carried such a large proportion of their body weight on their legs that they didn't need springs in their saddles, and they were weight-concious enough to begrudge the weight of the springs. Sporty cylcists also preferred unsprung saddles because they made it easier to pedal rapid cadences without bouncing.
When the bike boom struck, and everybody in America bought a racing-style drop-bar ten speed, the unsprung saddle was part of the deal. Unfortunately, neither the un-sprung saddle, the drop handlebars, nor the narrow tires suited the needs of the more casual, "recreational" cyclist.
The mountain bike revolution was a movement away from the drop bar and the narrow tire, but the unsprung saddle remained. Since the mountain bike came with big fat squishy tires, the tire was able to provide enough shock-absorbency to make the bikes reasonably comfortable to ride. Unfortunately, those same tires also made the bikes slow and hard to pedal.
Despite fashion, I believe that saddles with built-in springs make a great deal of sense for most cyclists, who favor a fairly upright riding position which puts more of the rider's weight on the saddle.
If a simple sprung saddle doesn't offer enought suspension travel for you, you can buy a seatpost with a built-in suspension mechanism. There are two families of suspension seatposts, telescoping and linkage types:
This type of seatpost is unobtrusive and takes up little space. Unfortunately, the sliding contact between the inner and outer tube can sometimes result in excessive friction and binding. This type of post is also prone to developing rotational play as it wears.
The telescoping mechanism works best when the load is applied right along the axis of the post, so most posts of this type have saddle clamps with little or no setback. Unfortunately, this causes biomechanical problems for many cyclists, since most frames are designed for use with a seatpost that has a reasonable amount of setback.
Linkage seatposts tend to be heavier than telescoping models, and, since the suspension mechanism is all above the seat tube, they can only be used by cyclists who can fit their bikes with a considerable clearance between the saddle and the top of the seat tube.
Suspension seatposts usually have a preload adjustment, which is normally set for the weight of the rider, so that the suspension won't move from just the rider's weight, but will only travel when the bike hits a bump.
Some bicycles have no seat tube at all, and attach the saddle to a cantilevered beam, which points back from a point just behind the head tube. This beam may be made flexible, to provide a very good suspension system with no moving parts. Although this system goes back at least to the 1940s, when there was an Italian bike with a spring-steel beam, it didn't really catch on until the 1990's when the Softride (originally called "Alsop") beam was introduced. This composite beam is sort of like a mini-diving board, and provides excellent rider comfort.
There has recently been a great deal of hysteria on the subject of cycling-related impotency. The thrust of the argument is that the rider's weight flattens the penile arteries against the saddle, reducing blood-flow capacity of these articles, which are required for tumescence.
I can't claim any medical expertise, but it is my opinion that these problems in most cases are related to poor adjustment or poor choice of saddles, such that the rider's weight is not being carried properly by the "sit bones." In particular, having the saddle too high or tilted down too far, will lead to the rider sitting on the narrow part of the saddle, which may block these arteries, and also possibly do nerve damage. This sort of mismatch can also create pressure on the prostate.
Cyclists who have problems with this, or who regularly experience numbness, should experiment with saddle position so that the sit bones are carrying their share of the load. Cyclists with persistent problems should consider switching to a recumbent, since recumbent seats are thought to eliminate this sort of problem.
Most higher-performance bicylces come with saddles designed for men, not for women. Due to the wider hips of most women, this can result in the sit bones overhanging a narrow saddle, leading to painful pressure on soft tissues.
In general, women's saddles are somewhat wider and somewhat shorter than those that work best for men. While not all women require a female-specific saddle design, most do. Many women suffer displaced discomfort as a result of riding an inappropriate saddle: In many cases, the only way to reduce direct saddle pain is to tilt the saddle down in front. This may reduce the acute saddle pain, but creates a tendency to slide forward. This sliding must be resisted by pushing backward on the handlebars, which often results in sore hands, wrists, shoulders or neck!
Some newer women's saddles have a large cutout in the middle to eliminate pressure on soft tissues. These work well for many women, but some riders find the sharp-ish edges of the hole irritating.
For many cyclists, the best solution to saddle discomfort is a totally different style of bicycle, the "recumbent." A recumbent features the basic position of an easy chair, with the pedals out pretty much straight in front of the seat (not "saddle".) The seat has a back, like a chair, which is important, since the rider's weight is not pressing against the pedals. The seat back provides a purchase so that the rider can pedal forcefully without sliding backward.
Many people believe that the recumbent is the bicycle of the future, and they may well be right. Recumbents are significantly more comfortable than conventional "upright" bikes, and in some ways are safer.
Unfortunately, recumbents are larger and more awkward to store and transport than conventional bikes, and, since they are not mass produced on the same scale, they tend to be substantially more expensive than comparable uprights.
The recumbent position also complicates the drive train design, so the mechanical efficiency is frequently less than that of conventional bikes. This is somewhat offset by the fact that many recumbents are more ærodynamic than uprights. Unlike the conventional diamond-frame bicycle, which has evolved and been refined over a period of more than a hundred years, recumbents are still in an early, immature design stage. As more and more of them are sold and ridden, the poorer designs will fall by the wayside, and better features will survive.
For more information on recumbents, check out the International Human-Powered Vehicle Association (I.H.P.V.A.)
|Articles by Sheldon Brown and others|
Since November 2, 1997
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