Monday, January 9, 2012

Why Penn Loves His Brooks Part 2

All My Posts Now Open With This

When I last talked about Penn’s adoration of his new Brooks B-17, I spoke about the advantages of the thin saddle.  At the end of that piece, I promised to return to the subject and talk about another reason he and his Brooks get along so well: saddle width.  Paying attention to saddle width is another way a rider can custom-tune their equipment to their anatomy. 

Remember the pelvis?  Well, good; your sit bones are going to play an important part in this discussion, too.  The location of the ischeal tuberosities upon which you perch are, of course, dependent upon the size of your pelvis—the wider your pelvis, the further apart these two points of intense contact are and vice versa.  So the size and shape of your “contact patch” with the saddle depends primarily on your bone structure. 

This point bears repeating:  the width of your saddle is determined by YOUR bone structure.  I emphasized that pronoun because people make a lot of misguided assumptions on this issue.  It is generally taken as a given, for example, that a woman needs a wider saddle than a man.  People make this assumption because women generally have wider hips than men because they have to move a baby through there.  But while that’s a generally rule of anatomy, it doesn’t tell you anything about any particular individual woman.  For men it is the same; a big guy may have tiny hips under all the flesh or he may not.  You cannot guess by looking at yourself. 

Your pelvis deserves better.
In any case, the wrong saddle width will cause you problems.  If you have too narrow a saddle, then it will fall between your sit bones, leaving them perched precariously at the edges.  This will result in the saddle being driven like a splitting maul into the soft tissues of the perineum and genetalia, the soft tissues that are usually protectively suspended above the surface of the saddle.  A cut-out saddle will not really help here—it will act more like a cookie cutter.  You will probably also spend a lot of time shifting from side to side, trying to get a solid perch on your bike.  Similarly, if you have a saddle that’s too wide, your hips will fall in the center of an expanse of leather and plastic.  All of the problems with friction, heat, chafing, and impairment of leg motion we talked about with an overly-padded saddle return—or are raised to the third power if your saddle is both too wide AND too poofy.

To complicate matters futher, because of the geometry of your pelvis and legs, the more upright your position on the bike, the wider the saddle you need.  The more aero you get, the more narrow a saddle you can get away with.  Besides their brutal weight, this is another reason you don’t see the Brooks B-17 on a lot of racy bikes—if you have significant saddle-to-bar drop, the Brooks ends up being too wide.  If you put an SLR on a beach cruiser, you will need some sort of lever to extract it from your body at the end of the ride.  In practice, this rarely arises as a significant problem, though, as the absurdity of the two examples just given generally works to prevent people from trying them.

All of this speaks to why saddle recommendations are generally useless:  everyone’s anatomy is unique to them, and their bike fit and riding style are additionally idiosyncratic.  All of this also means that perhaps you can’t have the saddle you really want.  Specialized’s idiotically-named top racing saddle, the Toupe, is a sleek and enticing piece of bicycle engineering that comes no wider than 143mm because professional bike racers are all freakish bird men.  For me, it is forever off the table.  Finding the right saddle is generally a time- and money-consuming marathon of trial and error, but taking a tape measure with you to the bike shop can cut it down by at least eliminating the non-starters.  (Annoyingly, very few manufacturers advertise their saddle’s dimensions, so you have to do the legwork.)

To return to Penn’s situation, the Brooks B-17 is a whopping 170mm wide where the typical men’s saddle runs somewhere in the mid-140s.  In person, Penn is more wiry scrapper than bruising behemoth.  He has the appearance of a man who will survive easily in the backwoods and mountains when he finally turns his back on civilization.  Nevertheless, it turns out that the guy has a wide pelvis.  Penn also rides with his bars at saddle height these days.  The Brooks is considerably wider than the saddle he replaced, and as a result, it provides a good fit for his body to do the long and repetitive work of cycling.  Thus, love.

1 comment:

  1. Damn, Val, that's a fine signature photo! Always raising the bar!

    As for Penn in the backwoods,I think you're right on. He does have a kind of literary Survivor-man schtick going on.


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