Shells can flex and rails can bend, leading to contact with the seatpost clamp or head, ruining the suspension of the saddle and causing discomfort, and the saddle padding can excessively compress under weight, losing cushioning, so yes, there are rider weight-related issues with saddles.

It can be hard to know which saddles are unsuitable, as few manufacturers publish weight limits, and because saddle adjustment and seatpost type are wildcard factors which can mitigate or exacerbate the weightbearing limit.

It’s also hard to know if more padding will yield comfort or cause discomfort, so be aware that solution maynotbe a panacea. Generally more padding is better for heavier riders, but I think it can be overdone and become a detriment.

In short, there are no easy, surefire answers as to what any individual will find comfortable to sit on, regardless of weight, so trial-and-error is how it’s done. Getting some tips on where to start looking could save time, and the Clydesdale subforum might be a good place to start.

I’m 245lbs and have good results from both San Marco ShortFit Racing and Fizik Aliante R3 saddles, both of which would seem to be unlikely choices as lightweight, thinly padded saddles, but they work for me. Saddle shape is very important to comfort.

I also am pleased with SQ Labs 611 Active saddle with the lightest elastomer installed, even though I am over the rated weight max. I’ve been on it for probably two, maybe three years, on my daily utility bike, but maybe the high volume 650b x48mm tires provide critical extra suspension. Go figure.

Good luck!