Recumbent riders are.....

[betty swollocks]

low-down bums.
That was my contribution years ago when a bike magazine* ran a competition asking for a name for 'bent riders.
I didn't win: the winner was..... 'recumberrumblers'..... ugh!

* I think it was 'Bicycle Action': anyone remember that?

 

[Mr Phoebus]

Nice play on words. You were cheated!