My .02, as I’ve had a few saddle sore issues:
- For me, sores are usually a combination of a chamois that doesn’t agree with me and getting very wet/sweaty. Fabric rubs your skin differently when it gets saturated. This is another reason to have really good fans around your trainer.
- I’ve had bibs from Verge and JLVelo that really didn’t agree with me. Once the same pair of bibs irritates me twice, they go in the trash. It just isn’t worth it. It might not even be the brand of bib or chamois, but one bad stitch or some little manufacturing issue.
- Having just three bibs (if I understood you correctly) seems suspect. Chamois wears out; you might just need some new bibs. Also, if you are wearing shorts, rather than bibs, try some bibs; the straps can hold the chamois in place better.
- Try to wash the bibs as soon as possible after riding. If they are going to sit for days before being washed, rinse them out. I rarely machine dry Lycra, but turn the bibs inside out and let them dry thoroughly after washing.
- Chamois cream is an individual thing, but I only use it when I’m doing a very long (>5 hours) or very hot ride.
- All chamois cream isn’t the same. Get some samples of other brands to see if you’re reacting to something in the one you’re using.
- Bibs that are too big/loose can be irritating. If you machine dry Lycra, it breaks down, contributing to looseness.
- Riding a trainer holds you in a static position on the bike. Give yourself a break and move around a bit at regular intervals.
- I find Rapha classic bibs very comfortable, but too expensive for daily trainer work. Rapha’s core bibs are less expensive and are what I train on most days. I’ve also found Assos and the higher-end Castelli and Pearl bibs comfortable.
- If you do any manscaping, avoid using a razor. Blades cut hair at sharp angles that can really irritate the skin.
- Once you do get irritation or a sore, treat it like a wound. Keep it clean and don’t ride on it; riding on a saddle sore makes it worse. In general, well-moisturized skin is more resilient and injury resistant than dry skin, so consider a daily moisturizer.
Good luck; I hope you get to the bottom of it.