I understand that 'fitting' one's choice of bike to one's body is a balancing act. Right now I'm working with seat size (I'm closing fast on 76th birthday, weigh 180 lbs, 5'-9" barefoot) with the '23 Tarmac SL-7 I acquired early last September, as an 'upgrade' from the '72 Motobecane Grand Record I'd been riding since early 1972.

First off I mounted a Selle Royale padded seat I'd had on the MotoGR to the Tarmac, but over time & with use I found it too wide as well as a little chafing. Recently I mounted the hard Specialized seat it came with. I just measured that, came away with 145mm at the widest point. It's vastly more comfortable than the SR I'd started with but even with padded undershorts I'm finding it a little too wide.

Using the 'tinfoil method' I've measured my sit-bone spread at 125mm.

At the instigation of a local bike fitter I'm slowly working with changing both seat height as well as seat setback (one at a time) too as I grow more comfortable with how my body fits the SL-7's cockpit. Seat height as of now is 70cm, setback is 64cm (steerer center to widest part of seat), set dead-nuts level with the 'bars at the hoods.

The greater question is: do I use the sit-bone spread # as a hard guide for selecting a more appropriate seat than what I've been using? I don't have a lot of options for trying out seats before buying where I live & ride.

Riding trainer 100% until weather permits a return to outdoor road-riding in (hopefully!) a few more weeks. Trainer's a different experience to what I know of my (strictly recreational) road-riding so whether that should influence my choice of a new saddle I'm welcoming input.

Not making a saddle recco, but if it works on a trainer, it should work on the road. Doesn't everyone get out of the saddle more when riding outside vs a trainer?


Not trying to be a smartazz, butt....for saddle issues: 1. get out of the saddle more while pedaling, 2. relieve pressure whenever coasting, 3. practice pedaling with 0.5mm between your saddle and your sitbones (puts more burden on your strong leg muscles than soft tissue spots.)

Good Luck

Sit bone measuring is by and for Specialized saddles. You don't ride on your sit bones, and the outer width of the saddle has only a little bit to do with how wide the top of it is. It's like measuring your ankles to determine shoe size.

The saddle I sell is narrow where it needs to be and wide where you sit. You should consider it.

My first ride on a Selle SMP TRK was a revelation. If you are experiencing pain in your crotch from pressure, I would make sure to try one.

Well, yes, at least that's been my experience. But trainer riding's not like road biking; gravity affects rider's body differently in each endeavor. I get off by butt vastly more often when road riding than on trainer.

I agree and incorporate all of that in my road biking style. On a trainer it's not as applicable, at least for me, not yet... if ever.

Tell me more please, and if you would let's take this to PM.

No, no pain, just a bit of chafe. And not often, easily tolerated.

Mostly I want to be prepared once the outdoor riding season beckons me off trainer and out onto the roads around here.
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Yes = my 1,2,3 for outside.

2nd the SMP comment from @Fredo76. I ride an SMP and my go-to is SelleAnatomica with cutout. I have several leather saddles that were modified for a center cut-out.