I'm 19 so it's kind of like - To do or NOT to do?? Haha. Problem is I have REALLY hairy legs, so idk. Sometimes it's just a cyclist thing, for looks/help with first aid.
You're considering shaving your legs for one bike ride? If you have a partner, ask him/her for their opinion. Unless your hair is so long that it might become entangled in the spokes of your wheel or so bushy that small animals might become trapped in the hair, it won't make a difference.