3D Saddle Pressure Mapping is a newer technology that, in my opinion, has changed the accepted knowledge of what’s possible in bike fitting much as infrared motion capture did a decade ago.
It’s capabilities are vast enough to really shed light on the black box that was rider-saddle interaction:

• exactly how much pressure is being exerted on all aspects of the saddle
  • this measurement is quantitative and we have the ability to change the unit of measure (psi, mmHg, mbar, kPa, N/cm^2, among others)
• a rendering of the magnitude and direction of movement of the pelvis
• the system can also track the movement of the left and right sit bone as well as the pubic bone individually
• data is automatically analyzed to determine the number of mm^2 of saddle being contacted as well as how much loading the different quadrants of the saddle are experiencing (i.e. how much more is the right-rear portion of the saddle being loaded versus the left-rear?  is the nose of the saddle being loaded more than the rear half?)

Having all this information is a game-changer because prior to its inception we had to visually assess how the rider was interacting with their saddle, and rely on inferred information from the infrared motion capture data, and the client’s subjective notes on how they thought they were sitting on it.  We could make some good educated guesses about what was going on between butt and saddle, but it was far from perfect.

Now we can see exactly what’s going on.  There is very little guess-work.

To illustrate further how powerful this system can be, I had a client in the last week or two that I might not have been able to help before I started using this system:

Some cyclists really struggle with their seats.  Despite having a complete bike fit and testing numerous saddles, I have a handful of clients that struggle even when everything else has been optimized to the best of our abilities.  

As you might imagine these clients will often be open to less traditional solutions.  Some newer saddle companies, like ISM and Cobb Cycling, have some alternative-styled saddles that they market heavily to women and invariably some clients are interested in exploring these options and for good reason — these are good saddles and occasionally they can help solve a recalcitrant problem that other, more traditionally-shaped saddles could not.  The problem with these saddles is that they need to be set up very differently than a standard saddle and even when set up properly they can be feast or famine – they might cause things to be much worse or they might be shangri-la and very tiny adjustments of the saddle are occasionally the difference.

In most situations when they do work, I can usually get the person to have one spot on the saddle where they feel really good.  This might seem like the normal way things should go — of course there’s one “good” spot….you only sit on one part of a saddle, right?  Well, actually, in many circumstances most asymptomatic riders on traditional saddles can sit slightly differently on the saddle depending on the conditions — how tired they are, whether they’re on the tops, the hoods, or the drops or perhaps depending on if they’re climbing a steep pitch.  All these variations and more put you on a slightly different portion of the saddle.  We’re talking about millimeters of difference, but as I repeat to my clients “millimeters matter.”

The difficulty with the ISMs and Cobbs is that although they might solve a saddle nightmare that no other traditional saddle has been able to, we might only be able to eke out one good spot on it. (Interestingly, I have many asymptomatic riders on these saddles that have no such issues and can sit in 3 or more positions on them without difficulty. Unfortunately but not surprisingly, it seems that those who struggle with saddles have less leeway on even the saddle that does work for them.)

My recent client, was one such cyclist, it appeared.  She struggled with a couple traditional saddles and each time we used the pressure mapping I could see that the location of the pressure changed but often the “point of maximum pressure” was relatively unchanged.  More importantly she was still uncomfortable.  

Finally, we began to see some good results with an ISM Prologue saddle — it is a split-nosed saddle with a higher rating of cushioning on it and a slightly longer, narrower shape.  After two or three tweaks to the saddle’s fore/aft and tilt posture (and these were small changes of less than a degree of tilt each time and a millimeter or two fore/aft adjustment) the point of maximum pressure began to dissipate and this mirrored her subjective sensations about how she was contacting the saddle.

What’s more is that based on the angle of her pelvis and the width of her main contact points we could determine with some accuracy exactly what anatomical part of her pelvis was contacting the seat.  From here I was able to coach her, again via the pressure monitoring and another tiny saddle adjustment, onto a slightly different portion of her pelvis that I figured she would also potentially find comfortable.  Over the course of a week we tested both of these positions and found the second to be even more comfortable than the first.  The first still allowed her to ride for multiple hours with only minimal discomfort and no numbness, which was a huge improvement over the 20-30 minutes and then severe irritation she was getting before, but the second position afforded her a nearly “invisible saddle”.

Because I was able to make use of objective loading data to inform my decisions and also to educate my client (and allow her to correlate with her own subjective sensations) we were able to take her from severely irritated and uncomfortable in any position to completely happy in two different setups.  This is the best example of what benefits can be had when we have access to great objective information.