I've been cycling for over 20 years and have yet to find a pair of arm warmers that would stay up on my arms.
So I decided to knit my own. I started at the top and knit down using the magic loop method (2 at a time on one circular needle). The wool sock yarn has aloe and jojoba oil in the fiber as a built-in skin softener that should last for about 15 washings. I made them extra long with a thumb opening at the hand. The extra ribbing at the top and wrist make sure I have a snug fit. I'll be writing the pattern up later.
I never thought I'd need arm warmers in FL, but this time of year they are perfect for the below 50° mornings that warm up fast.