[jdmitch]

I don't think it's that obscure in British english usage, even outside of cycling contexts (source: American living in the UK)

[FabHK]

Interesting. It's not in the Oxford Dictionary of English powering the Dictionary bundled with macOS, and it's not known to dictionary.com, so I'd say it's fairly obscure.

http://www.dictionary.com/misspelling?term=palmares