I don't wear motorbike leathers but I do lots of sport so wear a fair amount of lycra and have no problem with my LibrE.
It is positioned under your arm so not likely to be in a place which should experience lots of rubbing from your leathers.
Some people find the stickiness becomes unsticky if it gets very wet. So if you get sweaty under your leathers it may be a problem.
It you are concerned about it coming unstuck, I think some people use things like tagaderm to keep their's in place during swimming, for example.
(Libra is a sanitary towel and I assume you are not asking about that!)
No problems here either - I’ve got very thick Crowtree leathers, and it scans fine through them. I wear mine on my upper chest rather than my arm though - I’ve found it catches less on clothes and doorframes.
I'm not @Mel , but I have worn them on my chest in the past. I loved it there for comfort, both in scanning as in applying, but the 3 sensors I wore on my chest read around 2 mmol/l too low, as opposed to the ones on my arm which generally read only 1 mmol/l too low. Not statistically relevant, I know, but still I've gone back to arms.
It’s super comfortable and I’ve found no difference in accuracy - but I use it with a MiaoMiao transmitter and can blood calibrate it. So even when the official Libre app and scanner are reading off, I’m confident in the results I get.
I wear mine under armoured motorcycle jacket (not leather though, im not hat cool yet), no problem, scans fine, just have to remember where it is this time as I cant feel it, a bit like metal detecting with my phone