I agree with Ruth- a recovery drink with a 3:1 carb/protein ratio is very, very important within the first hour after your ride. I'd say ASAP. Endurox or choc milk.

I think dead legs at the start of a ride is either a sign of overtraining or not a good recovery. My legs feel like they're bursting with energy at the start of a ride, like they can't wait to go.

I'd also be eating/drinking something with protein if I was out more than two yours.

Nanci