To be on a long bike ride (training ride or race)and trailing a person or people very closely (thereby minimizing your effort and making the person in front of you do all the hard work)all day until the last leg, then taking off to finish the ride first in front of your buddies like you are hero.
"Did you see him last week? He is such a Wheel Sucker. He pulled a wellesley and rode up my back for 60 miles and then took off like a hero to finish the ride in front of us all!!! He should take some HGH, rather than make me do all the hard work"!
A road cyclist who stays behind other cyclists' wheels so that he/she can draft behind them, and thus conserve his/her own efforts.
George is the worst wheelsucker of all, always feigning fatigue when we ask him to be at the front every once in a while.