In a post about 18 months ago, The Logging Road Cyclist shared with you his thoughts on the ISM line of saddles, in particular the PM 2.0, their MTB specific model. Let us be clear: for relieving pressure on the perineum, these can’t be beat. TLRC made a bit of a fuss about getting the saddles set back far enough to work properly, given that he had to spend a lot of green on various setback posts for his collection of bikes.
ISM has a lot of guidance about how to set up these unique saddles, but TLRC found it rather vague, especially the setback. His best fore-aft starting point after a lot of experimentation was surprisingly simple: set the ISM so that it’s widest point is as far back as the wide point of your existing standard saddle.
ISM also say that the saddle should be perhaps 5mm lower. While fiddling around with this, TLRC found good advice on (of course) YouTube for setting saddle height in general: Set your saddle so when your heel is on the pedal your knee is locked out (a pretty standard seat height trick), then lower the seat 2-3 cm. This will likely feel way too low. On a ride, slowly raise the seat until it feels right. TLRC found that it is pretty obvious where that is.
As for tilt, TLRC put the nose down and raised it bit by bit until he felt that he wasn’t sliding off the front.
Even with a lot of experimenting over a long period, TLRC was not able to get any of the ISM saddles (and he tried almost all of them) to work satifactorily. His problem was chafing not between the thighs (the most common complaint leveled at ISM), but rather behind his thighs at the very top and towards the midline. After a lot of effort he determined that it was not the width of the twin noses of the saddles causing this, but rather the width further back: the saddles did not taper fast enough towards the front from their wide point.
Hoping that their narrow PN saddles might help, he tried a few of them and found a different problem. The noses were quite narrow, but hit TLRC at a sensitive spot on his pubic ramii causing him some disturbing and lasting pain that eventually dissipated.
Now, this sounds like TLRC is really raining on the ISM parade. He most emphatically is not. ISM makes saddles that do not crush the delicate structures in the perineum. They do this very well, and perhaps better than any of the other several thousand saddles TLRC has tried. They just happen not to fit TLRC very well, something that he regrets. They are a well designed and well built product that do exactly what ISM claim. If you have damage “down there” or wish to prevent it, ISM should be one of your first stops.
Luckily, TLRC has lately tried new models in the SQlab line with excellent success and he will be reviewing those as soon as he has some more experience with them.