I'm the complete opposite, due to the fact my rides are far more intense (on my CNS) than my weight sessions. I couldn't possibly perform weight work (to the standard of where I would want it) after coming back from an intense aerobic workout (30-70 miles).

You could also be setting yourself up for injury doing weights after cycling as the muscular system loses strength, particularly in the back, which is prone to damage. Anyone performing deadlifts/exercises involving the back, from putting 50 miles into there erector spinae/back (weakening all the time) is on the road to injury.