Specialized Saddle Fit/Sit Bone Width Question

I’ve been on a 155mm Toupe since a Specialized store used the Assometer to tell me that was the size I needed. I remember the salesperson had me lean forward to sort of replicate my position on the bike while he did the assometry. Now years down the road, I’m questioning the measurement he did.

I cut out a piece of cardboard using the outline of the Toupe; taped it to my saddle; and then sat on my bike in my usual riding position. Then I felt for the depressions in the cardboard and measured the distance between depression centers and got a measurement of about 100-ish mm. I cannot figure out how that Specialized sales person did the assometric data reduction to come up with 155mm for the Toupe. According to the Retul app on Specialized’s website, I should be using a 143mm saddle.

Am I missing something here?

The end goal is to buy a Power Pro with Mirror in the right size. I’ve noticed that I get a bit sore as a result of the back of my legs hitting the saddle, but that’s been liveable and not a real issue. Well, it’s at least an issue I’ve lived with for the last year or so. I had assumed that the Specialized salesman was a qualified assometrologist. Maybe that assumption was wrong.

Does anyone have any insight here?

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So I have had the exact same experience as you except I have always been using a narrower saddle. 128-143 normally. My measurement was also right around 100. You are then supposed to add 20-30 to that.

However I was getting horrible saddle sores and a fitter used the specialized and while it was still at 100 he said I should use the 155.

This has pretty much solved my issues, however I will still get some irritation if I am putting in lots of long days.

Same day I was told to get a 155 I was told my a different guy at a different store, but same company that was a 143.

Next day went to a completely different store and the person told me 110. I asked her to show me 110 saddle. Had no idea how to fit.

My long winded point is it seems most people don’t know what is going on. I have been measured about 6 different times using different methods and have gotten about that many recommendations.

If a 155 saddle works then keep using it. Specialized also offers 30 days to try I believe? At least that was the case with their shoes.

Used to use the 143 toupe and have found the s works Phenom to work the best for me. Wish they would make it in the mirror version.

Power has been ok, Romin my least favorite have tried them all in about every size and version, but mirror.

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I have a nice 143 PP Elaston I’d like to sell…

That was going to be my suggestion exactly. They do offer the 30 day trial on saddles but I’m not sure if there’s anything different for the Mirror. I suggest emailing their customer service address as they’re extremely helpful & quick to answer.

Good luck!

Love it.

I am not a qualified assometrologist but I suspect that “take the assometer reading and add 25mm” recommendation is one of those things that works on the population level but not on the individual level.

I think the final answer would have to depend on riding position and hip flexibility which both influence the forward rotation of the pelvis. As I understand it, the more the pelvis is rotated forward the narrower the saddle.

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So after purchasing a kickr bike which has afforded me way too much ability to tweak my fit and experiment with different saddles, I’ve come to the conclusion that

  1. saddle measurements are just a starting point due to the difference in shape of the saddle. For example I have both an s works power and a prologo ndr in 143. But the prologo has much more curvature, making it effectively narrower than the power.

  2. sit bone width is not the only factor which should be considered when determining the saddle size. After messing around with my fit, I believe a knee issue I am having is due to twisting pelvis and hip drop. I measure into a 143 saddle size but 155 width provides me with a larger platform and provides stability to help address these issues.

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Width is only 1 factor, of course. Different saddles have different curvatures side to side and front to back. The rate of taper (how quickly the saddle narrows) also varies. Finally, your position on the saddle is hugely affected by saddle height, reach, drop, and foot support.

What I’m getting at is that this may well be a more complex question that 143 vs 155. I’d strongly suggest a very good bike fit. Most such will start with really nailing down your platform: getting saddle height right, getting cleat placement and foot support right. Then when that’s dialled in, many people actually find that many saddles are at least ok.

That’s certainly been my experience: once it was assessed that my ‘low on paper’ saddle height was actually right (I’m a significant heel dropper), have a slight functional leg length discrepancy so need a shim in one leg, I can run 3 different saddles on my 3 bikes and I don’t notice much difference on sub-3 hour rides.

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Who has issues with under three hour rides? :sweat_smile:.

Everything always feels great until after that third hour, it is finding the saddle and shoes and bike fit that works 5-12 hrs in that’s hard to do.

Retul aka the fancy digital version of the assometer says 143 is fine, but I most likely have tight hips which cause me to rotate on the saddle putting more pressure on my right side, again according to the assometer and it’s reader. So I work on loosening my hips and tightening that core. Add in a wider saddle and thing seem to be better, although this year has led to regression.

I’m gonna give the 143mm Power Pro with Mirror a try. With Specialized’s 30-day return policy, I can get the 155mm flavor if the 143mm version doesn’t work.

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lots of people.

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Wait, what - people ride for less than 3 hours?:stuck_out_tongue_winking_eye:

Hence the smiley face to indicate joking or sarcasm.

Just realize that the power is a much much different saddle than the Toupe. Shorter, more curve and less ability to move about on it. Not saying one is better or worse, just very different so don’t just focus on width, as others have already stated.

Here is an old thread on it:

Yes, I realize that. I don’t move much at all on my Toupe, and from what I’ve read, I think the Power Pro will work for me.

Of course what I’m about to say is a personal fit choice, and n = 1.

I have also dabbled in the various methods of assometry, and although I could reasonably use a narrower saddle if in an aero position all day, I can do more on a wider saddle. I don’t see any downsides in my riding on a 150-155, and only upside if I’m in a less aggressive position or on a longer ride.

As for the specialized saddle choice, I recently invested in a romin mirror in 155 and it’s phenomenal. In some ways I wanted to hate it due to the cost (even discounted!), but I absolutely love it. I never really struggled with the bontrager Montrose until 6h plus, but the romin is on another level of comfort - even to the point of feeling fine after a 10h ride on Sat. I’m not a huge fan of stubby saddles (again personal preference) but one thing to note is the power mirror is a lot firmer than the romin mirror as well. In my opinion it’s definitely worth checking them both out, but the romin is a much comfier platform.