A lot of athletes are riding split-nose saddles. According to our polling, more than 6 in 10 of you have already made the switch. How do you “normalize” for the change from standard to split-nose? When you swap saddles you probably don’t want to change your position. Let’s talk about how you mount a split-nose saddle so that only your saddle, and not your position, changes. First, let’s talk about what a split-nose saddle is.

There are two kinds. You have the Fizik Tritone and the Cobb JOF Randee, where you actually do rest a part of your tender tissue in or on the saddle, and you’re riding – ahem – half commando. It might be that the Specialized Sitero, Selle Italia Iron Flow, and other saddles are in this category (I don’t yet have enough feedback on how everyone sits aboard them to yet say.)

Then there are ISM’s saddles, especially those that are snub-nosed, like the Road and the Racing, and most triathletes hook their ischial tuberosities (sit or sitz bones) on the twin noses of these saddles (which is why I call them “split-nose”) and you’re now riding full commando, everything forward of your sit bones riding on thin air. These saddles are popular because you vacate the pressure on your perineum (yes, women have them too) replacing it with pressure on your sit bones. Many feel this trade-off is preferable.

But you can’t just remove from your bike a standard saddle, like a Fizik Arione Tri2, and replace it with a split-nose saddle. If you don’t want your hips to move when you replace a standard saddle with a split-rail saddle, your saddle MUST move. A lot.

The way saddle placement is often measured is by where the nose is (or “noses” are) in relation to the bottom bracket, and I’m talking about whether the nose sits behind, in front of, or even with the BB when you drop a plumb line from the saddle nose. If your “old” saddle was bolted to the seat post right in the middle of its rails and you simply replace that saddle with a split-nose saddle, bolted in the center of that saddle’s rails, the leading edge of the snub-nosed versions of ISM saddles will sit about 4cm behind the leading edge of the standard saddle. The distance from the saddle rail center to the nose on a snub-nosed ISM is, on average, about 4cm shorter than on a standard saddle (110mm versus 150mm). What I'm calling a snub-nose ISM includes the Racing, just below.

If replacing a standard saddle for a split-nose automatically moves the nose back 4cm, that’s a LOT. Isn’t that enough to account for how far forward you sit on one of these saddles? Usually the answer is no, it’s not. ISM thinks that its saddles need to be moved back more, so that that nose sits at least 5cm behind where the nose of the standard saddle would sit, and as far back as 8cm. In other words, if you simply take off a standard saddle and replace it with a split-nose saddle, and ride that saddle the way I describe above, your hips will be thrust forward from their former place – you’re changing not only your saddle but your position.

If you simply bolt on a split-nose saddle on that part of the rails where your standard saddle was clamped you’ll ride steeper (more forward), and if you make no other change your cockpit will close up (your elbows will be drawn back toward your knees, your shoulder angle will close). Furthermore, the distance from the rail-center forward to the saddle’s nose or tip is longer for other, sloping-nosed ISMs, like the Attack, so these saddles might need to be moved back further to keep your position unchanged.

Fitters, shops, coaches, triathletes, and manufacturers are having trouble wrapping their brains around the need to move the saddle nose that far back. Most just can’t accept it, or believe it. Accordingly, many riding these saddles have their hips more forward than they did prior to their moves to split-nose.

At the top is a picture of multi-time and reigning Ironman World Champion Mirinda Carfrae, it’s of Mirinda, aboard her ISM Attack, in Kona last year, in a race she won. Is she more forward than how she’s ridden over the past several years? No. Not that I can see. She’s ridden ISMs for years, and she’s ridden them all steep, but she’s ridden several styles of ISM the Podium, Breakaway, and Attack. Apropos of nothing, but your probably won’t see Mirinda on ISM in 2015.

This image of her bike above is a graphic example of what I’m talking about, for the purpose of analysis. This is Mirinda’s bike from 2012. These bikes, set up in this position, have worked admirably for her for years. Certainly race results would back this up. But if you look, her historical placement of this saddle right over the BB or very close to it. This is just typically not how these saddles are set up. A split-nose saddle positioned this steep will yield a very steep position, even for a rider with a saddle height as low as Rinny’s, and a position like this would rarely be ridden (legal or not) by a pro cyclist. I’m not suggesting she change her position. I’m just describing her position, and how forward a split-nose saddle perches its rider.

Mirinda is not alone in riding these saddles very steep. Just above is an image of Linsey Corbin in this past year’s Hawaiian Ironman.

As with Mirinda, most of Linsey’s photos in profile on the bike look very much like this, and have for some time, through both her Trek and Scott years. These women are not moving back and forth on their saddles, they’re nailed right to the front, this steep.

Am I suggesting these athletes move their saddles back, and their front ends back accordingly to maintain their proper cockpit distance? No. I am saying that if these ladies were to replace their ISM saddles with standard saddles, and if they were to maintain their identical body positions the noses of these standard saddles would be way, way forward.

I would also venture that the positions they’re riding in now are more forward than they rode before they switched from standard saddles, because my instinct tells me that their previous, standard saddles did not yield positions this steep.

Look at the cockpit distances, the shoulder angles, of both Rinny and Linsey. These are tight shoulder angles. This makes me wonder whether the switch from standard to split-nose occurred with all the rearward movement required to retain the old position.

If you look at hard-riding Daniela Ryf, above, she’s on an SMP. She sits it pretty far back, and in just about any pic I’ve seen of her, when you see the saddle when she’s riding it’s the nose you see, and not the tail. You can ride standard saddles very steep, but you don’t have to. The way Rinny and Linsey (and most others) ride their ISMs (and Cobb JOF, Dash and others) you’re pretty much committed to a very forward, steep position. What would happen to Daniela's position if she switched to split-nose and rode it the way Rinny and others ride theirs? Unless Daniela moved the nose back 8cm or thereabouts she'd be riding with a shoulder angle somewhere in between where she is now and where Linsey and Rinny are now.

I’ve only been talking about the women so far. What about the men? All the Specialized Ironman-style athletes finishing in the top-15 during last year’s Ironman – and there were a lot of them – rode Siteros. There were a lot of Fiziks, Prologos and Andy Potts is the only athlete I know in Kona’s top-15 last year on an ISM. Andy loves his ISM Road and that baby is pushed forward. Just like Mirinda's. But Andy might not ride it exactly the way I describe above. I love the changes to Andy’s position as it has morphed over the years. I used to have to turn away from my computer when I saw pics of Andy on the bike. Now, his position is nice.

One thing is undeniable about Andy’s current position: it’s way, way forward of where he used to ride. We had his fitter, Mat Steinmetz, write an article for us on how Andy’s position morphed to its current state (about 2 years ago). Mat wrote, “Because a person like Andy prefers to ride forward...” and I just think Andy did NOT used to prefer a forward position. Mat finally found a position that Andy could ride forward in during that 2013 session (mostly through shortening the cockpit). Andy really analyzed, and fixed, his bike from the top tube up first through Mat’s work on position, and then with TriRig’s help on cleaning up his bike’s front end.

But here’s the thing, and maybe Mat might want to comment in this if he reads it, were Andy to trade his ISM Attack in for a standard saddle its nose would be several centimeters in front of the BB for his hips to remain where they are, unless Andy sits that ISM uncharacteristically rearward versus how the women above ride theirs.

I just think in a lot of cases the ISMs aren’t move back at all on the rails when a saddle change is made (from standard to split-nose), and this places the rider’s hips several centimeters in front of where they were prior to the saddle change. This fundamentally changes the rider’s position. Here is Lionel Sanders’ bike, just overviewed on Slowtwitch. That’s a pretty steep placement of an ISM.

What’s the take-away for the typical consumer riding or considering a split-nose saddle? We polled you all, and here’s what we asked: “When you changed to a split-nose saddle (e.g., ISM) you moved your saddle nose back how far versus your old standard saddle?” Here’s how you answered:

0cm: 9%
1-2cm: 6%
3-4cm: 9%
5-6cm: 6%
7-8cm: 1%
Other: 1%
No idea: 30 %
I don't ride a split-nose saddle: 38 %

This means that only 11 percent of you are, for certain, riding split-nose saddles the way ISM recommends you do (if you answered this question realizing we’re asking about the NOSE of the saddle and not the saddle’s rail center). Further, this assumes facts not in evidence. First, you might be riding your ISM differently than most athletes do. Also, your previous position might not have been steep enough. A lot of riders have their positions “corrected” just by placement of a split-nose saddle on their bikes, if their pelvises never were able to rotate forward (due to point tenderness on the saddle) and if the cockpits (distance between saddle and armrest) were already too long. This might have been Andy’s case.

It might be that some athletes were just never forward enough, and now they are just because they stuck an ISM where their Fizik Arione used to be. It might be, however, that athletes have ended up with their hips too far forward because the fitter does not understand the profound difference between how one sits a split-nose versus a standard saddle. It certainly means that riders, fitters, retailers, coaches ought to carefully consider what a change to a split-nose saddle means, and mount and position the saddle with these changes in mind.