Ummm... is it so horrible to ride when you're sore? In my experience your legs can usually work it out... you feel a little sluggish for the first 20 minutes or so but then you're OK...
I've done some semi-high mileage running (not super hardcore, but around 65 miles per week). For me, running creates much more stiffness than riding... but when you're on a schedule, you go out and do your miles even if you're stiff... and it can suck at first, but usually it DOES get better during the run. Over time, you can do higher weekly mileage and longer long runs without much soreness -- the major obstacle becomes fatigue/just feeling depleted.
Then again, sometimes you do need to rest, too...
I can ride with sore legs but find the steep climbing tough.
It is never too late to be what you might have been. ~ George Elliot