Not “the black bibs”, but the Rion (Aliexpress and Amazon and probably direct) are of the same ilk.
For $30-33 delivered (in about 2 weeks from China), these are fantastic.
-Stitching quality is the same as all my “good” shorts that go up to Elite/$150 Pearl Izumi
-Chamois is comfortable, but not the nice perforated top layer I have in my Pearl Izumi or my Volers. It’s better than my Prorace shorts or my NZO’s, and is fine, especially considering it was 1/5th the price of the pearl izumis.
I would say that these are comparable to shop shorts that are in the $80 range, maybe the $100 range. If they had a perforated chamois top layer with a softer fabric, then they’d be right up with my pearls’.
Between Aliexpress and Amazon, there’s over 3500 reviews, and near 5/5. There are reviews that after a few rides some people found the fabric started to fail. I’ve only done one 45min trainer ride, and will hold off a review on aliexpress/amazon until I have used them 25 or more times.
For the average TR user who rides 3-4 times a week indoors for mostly 45-90 mins, then some of these seem like a no brainer to save your expensive shorts for the road/longer rides. I suspect I’ll use my oldest shorts on the trainer, then these for road rides up to a couple hours, and the Pearls’ for the all day missions.
There is a version on amazon with a pro chamois that is for longer rides. I’d have bought those if I’d seen them when ordering.