I started cycling last August when I bought my Tarmac. I hated the saddle that came on it (Specialized Toupe) and after trying a few others I settled on a Specialized 155mm power saddle.
It was great last fall, all through the winter indoors, this spring up until a couple weeks ago where now it is just plain uncomfortable. Previously I could go out for a few hours with no issues and it was fine during all workouts.
I’ve lost a bunch of weight, I was approx 205lbs last August and am down to 180 now, I’m putting out a lot more power now, my ftp was 204 when I started and is now 270.
Has this happened to anyone else, a perfect fitting saddle is now terrible all of a sudden, I’m wondering if my lower body fat and muscular changes have lead to this.
Your saddle could be sagging. I’ve had saddles that were fine for many years suddenly turn unsatisfying. Your bib chamois could also be compressed and worn out and contributing.
I just got my first set of Assos bibs and they were a huge upgrade for my rear end!
The saddle was brand new in September of last year but I guess sagging is possible.
I doubt its the bibs, I’ve got a pair of Castelli, The black bibs, santini and santic and I have this issue in all of them.
Well, you’ve lost 25 lbs. Do your jeans still fit? I doubt it. Might throw the Toupe back on and see how it feels.
Really hard to say.
If I had to guess, it’d probably be due to some physiological side effect from your positive gains. Losing weight and gaining power sometimes come at the expense of increased muscle tightness, overuse injury (resulting in overcompensating some other way), etc.
Nope, jeans definitely do not fit. I’ve put the toupe back on and its still as awful as I remember it.
None of the shops in my area are doing saddle loaners or returns at the moment so I guess i’m stuck for now, my only other saddle is an ism saddle we’ve got laying around but I have my doubts about that one.
Perhaps the saddle slipped down, back or tilted a little nose down. Just verify your measurements are still the same…
I need a saddle switch every once in a while.
I too like the Power, but I find after sitting on it for a couple months consecutively indoors I just need some slightly different pressure points.
I swap every 6-8 weeks (or one phase of training) between the Power, Power Arc, and the Pro Stealth, all of which feel very similar, but different enough and my backside very much welcomes the new saddle.
I’ll check that tonight, I know that the seatpost has not moved, I mark the seat rails and those are correct, I’ll check nose height, I like the nose slightly up.
Good man. It took me like two decades to figure this out… 
If the seat hasn’t moved it could just be plain old not being used to the time in the saddle. At the end of each block I’m always a little sore warming up (sitting more upright and light power on the pedals). After a regen/rest week I’ve recovered.
It’s not clear to me whether you’ve changed bibs since losing weight. When I lost about 15lbs, some (but not all) of my shorts became uncomfortable. If you bibs are loose enough that your chamois is held tightly in place then that can cause some nasty chafing and discomfort
Have you tried remeasuring your sit bones using one of the home DIY methods. You might be able to at least rule in/out a width issue that may narrow your search. I know your bones don’t change necessarily when you lose weight, but I would image it would have some impact on how that sit bone measurement turns out.
You can find some cheap-ish “versions” of popular saddles. I’m not sure how helpful it will be but for example, I bought the Easton version of the power saddle as it was only $26 on amazon to see if the short-nosed saddles would work for me. Decided at least that one didn’t.
I’ll try remeasuring my sit bones and see how that goes. I’ve had a few pairs of bibs the entire time riding and some new ones recently, I purposely bought tighter ones when I was heavier. I really don’t think its the bibs though, I’ve been at my current weight for at least 3 months and wear the same bibs then as now and I didn’t have any issues until very recently. I don’t get any chafing or similar issues at all.
for shits and giggles try dropping your seatpost 5mm for a week and see if that makes things better or worse.
I have a n=1 hypothesis based on my own experience going from 240-> 175lbs that my fat ass provided more cushion volume which effectively required a higher seat than when i lost the weight and had less cushion between the seat and my sit bone. i brought my saddle down slightly and things drastically improved.
You mention you like a slightly upward saddle position, when all else fails you could always try one or two degree’s down and see if that alters your perception.
The main reason I like it slightly up is to keep my sit bones in contact with the proper spot on the saddle, when I get lazy I put a bit more weight in my hands which leads to issues, the seat slightly up takes care of me moving forward and reminds me about the sit bones.
That is worth a shot, may give it a shot.
Another vote for lowering the nose. Good luck!
I’ve had a similar problem recently. Since gaining more strength and power on the bike, I’ve found more and more that my saddle (Fizik Arione Versus) is getting less comfortable, particularly at lower power when more pressure is put through the saddle.
I think part of that is how my form is adapting to putting out higher watts and also to changes in body composition. I’ve ridden some test bikes with other saddles and have found the support and comfort to be much improved. I get a new bike this week and will be upgrading to a Prologo Dimension saddle, which I’ve found to be most comfortable in my testing.
So long answer short, I 100% agree with you the change in body comp and power output plays a factor in saddle comfort over time.
Not sure how marking the rails ensures the seatpost hasn’t moved. It’s possible for the seatpost to slip a little into the frame, even if the saddle hasn’t moved with respect to the seatpost.
(Apologies if I have misread your post, and that you have checked all those things separately.