Bicycle Saddles - Base
The base of the bicycle saddle is the foundation on which all of the other elements are built. You can shape it a hundred different ways, make it big or small, long or short, wide or narrow, and mix in carbon, but it is still the base. There are four fundamental attributes of the base that contribute to comfort that we will discuss.
- Base dimensions and width
- Base shape & contours, including the nose
- Base relative flexibility
- Base relief area
Bicycle Saddle Width
The basic concept here is that your "ischial tuberosities" commonly called “sit bones” should primarily carry your weight when sitting on a bicycle seat. Different people have different widths of sit bones and in general women’s tend to be wider than men’s. A well designed bicycle seat will accommodate these variations. The bike saddle also needs to accommodate variations in riding position through the various phases of your ride. A saddle that only accounts for the width of your sit bones would be too skinny for most cyclists. Koobi has always made different width saddles and we know how saddle width contributes to comfort.
Choosing Your Bicycle Saddle Width
How does the cyclist know if he is in saddle nirvana on his bicycle saddle width? If the saddle is too skinny it well feel like you are sitting on a horizontal pipe, like the saddle wants to cram up your crack. Your sit bones should carry the weight not your crack. It will feel lousy!! If the saddle is too wide you will tend to get a chafing of the skin on the upper part of your legs like your upper thighs are getting rubbed raw. Research has shown that a bicycle seat design with a wide platform and narrow nose will produce a saddle that is comfortable for the vast majority of riders. (So why don't more saddle makers design them this way? Who knows?)
Bicycle Seat Length
Over the past 100 years there has been a variety of lengths of bicycle saddles. Conventional saddles have settled into an average length of around 27 cm in the past 20 years or so. The length of the saddle is still varied slightly for specific applications such as Triathlon saddles or woman’s saddles but in most cases it still settles into the conventional lengths.
Women’s Bicycle Saddle Length and Width
Unless you are a very small person, say less than 4 foot 6 inches that there aren’t many advantages to the shorter saddle. For this small population of shorter or smaller people, there are children’s saddles on the market. As further confirmation it is interesting to note that Terry Saddles, who market themselves specifically to women, has almost no difference in length and width between their men’s and women’s models.
Bicycle Saddle Base Shape
The overall shape and contour of a saddle influences how it feels. Ideally a saddle shapes should be such that when you sit on it. Your “sit bones”, also called "ischial tuberosities", are well supported. In other words your sit bones carry your weight most of the time. While other portions of your bottom will carry some of your body weight, some of the time, ideally your sit bones carry most or your body weight most of the time.
Moving Around On Your Bike Saddle
Cycling is a dynamic activity. Your position on the bicycle saddle will change throughout the various phases of your ride. Moving is one of the important aspects of creating comfort in your cycling. You see if you sit in the exact same position, even if it is on your sit bones then you tend to cut off the circulation to that spot. Ouch that hurts, and numbs after an extended period of time. You need to move about.
A Bike Saddle Designed for Movement
A well designed bicycle saddle will have contours that promote movement. The ideal profile of a saddles is relatively flat. This profile is the best for both promoting movement and for supporting your “sit bones” during the various phases of a ride. As you are standing on the side of the bike looking at the side view, a saddle should be nearly flat. Some saddles have a hammock like shape. The hammock shape will feel nice in the parking lot test but it cradles your bottom, holding it. As the ride gets long this cradle shape makes it harder to move about. You tend to get stuck in one spot. Gradually this lack of movement puts pressure on the same spot on your body cutting off circulation. Another shape that is evolving into saddles is where the back of the saddle is scooped up. This shape will also reduce your ability to move about on the saddle.
The Horn and Sides of a Bicycle Saddle
Another area of shape that will influence comfort is width of the nose (also called the “horn”) and how the rear of the saddle contours for your upper thighs. A well designed saddle will have a horn and sides that allow you both maximum control and maximum mobility. The nose of the saddle helps you to balance and steer the bike and keeps you from falling off the saddle when you hit a bump.
Nose-less Bicycle Saddles
A novel saddle shape showing up in the last few years are saddles with out a nose. The concept is the nose of the saddle puts pressure on your soft tissue region so to have no pressure have no nose. Although this is correct, you forfeit the balance and control that the nose provides.
Bicycle Saddle Function - Base Flexibility
To understand how the base of the bicycle saddle contributes to the overall comfort, let’s look at how the saddle absorbs energy. When your bike goes over a bump a portion of the energy is transmitted through your bike into the bicycle saddle. Various elements of the saddle absorb this energy including the cover, foam, rails, and the base. The flexibility of the base becomes an important factor in producing a comfortable saddle.
Bicycle Saddle Base Flexibility vs. Foam Padding
There are a number of companies on the market that use very thin foam on top of a moderately thin base. The theory behind these saddles is that the comfort is derived from flexibility in the base. That flexing in the base acts similar to foam, absorbing bump energy. The first challenge that these saddle makers have to overcome is an international Manufacturing standard that requires saddles to function for a 220 pound (100 kilo) person. The first challenge is that it is a huge problem to make a saddle that functions for a 220 lb person and still be flexible for a 180, 160 or 140 pound person. The second challenge is that a saddle may be very flexible for a 180 pound person but will be stiff for a 155 pound person & too flexible for a 205 pound person. These companies don’t rate their saddles as soft, med or firm. Nor do they rate them for a cyclist by their body weight. Due to these two problems, in the end the cyclist has a one size fits all. Ride them till you find one that is flexible for your body weight. The theory that flexibility in the base of a saddle should absorb energy is a solid theory. The challenge is bring it to market so that it will work for a vast range of cyclists.
Bicycle Saddle Relief Area - The Concept
Research, testing, and common sense all confirm that the contact points on a bicycle saddle have a significant impact on comfort. The human anatomy was designed to sit on the "ischial tuberosities", commonly called the “sit bones”. A well designed saddle will support the rider’s weight on their sit bones and minimize the amount of weight carried by the soft tissue region. Testing has shown that a center-forward relief area in the bicycle saddle is effective in reducing the soft tissue pressure while cycling.
Bicycle Saddle Relief Area - In the Beginning
Testing and research has shown that the optimal location for the cutout is the center of the saddle going forward. In 1997-1998 there were only two companies that had any kind of saddle with a relief area. They were Selle San Marco with a diamond shaped cutout in the center of the saddle and Terry saddles with a large cutout in the center of the saddle. Terry called their saddle the Liberator. Both of these saddles had the cutout more or less in the center of the saddle. A few years prior to this, Selle Italia had a saddle called the Mythos, which had a triangle shaped cutout in the rear of the saddle. Also in 1998-1999 a marketing company that specialized in bicycle products hired a marketing person who doctored on the side named Dr Minko. They borrowed Selle Italia’s Mythos rear cut out relief area and produced a line of saddles that they marketed as Body Geometry by Dr. Minko. They created a series of ads that gave the impression that cyclists were at risk of impotence and that their doctor-designed saddle would not allow this. Did they ever produced any independent peer reviewed evidence that their doctor-marketed, Selle Italia patented, rear cutout would reduce the chance of impotence? Don't think so.
Bicycle Saddle Relief Area - The Evolution
In the following years 1999-2005, Specialized gradually moved their cutout forward. They came out with a dizzying array of models changing models every year, moving the cut out farther forward each year. Currently their cut out is center and rear. During the same time period most of the industry did the same thing with their model line up. They came out with numerous models, gradually moving the rear cut out forward to center of the saddle. Recently at least three companies have a marketed nose cut out design. Koobi, Selle SMP & ISM.
Oklahoma Bicycle Society:
Saddle Base
created by John Wente
last modified:
August 10, 2007
URL: http://www.OklahomaBicycleSociety.com