I lifted last season during the season and saw great gains. I lifted harder this off season and without a doubt am way stronger which directly correlates to my speed on the bike that I can sustain. I have a very simple workout. A standing squat machine. I start with 5 plates on each side, and do 20 reps to warm up- add 2 plates to each side for another 20 reps - add one plate and then do as many as I can, started at 40, now closer to 50, take one plate off, repeat to max, do this until I am down to just 3 plates. (end of last season I could only do 5 plates) No rest between sets except the time it takes to take them off. Then go to calf raises, and max out on reps (always to fatigue)with descending amount of weight. Sometimes do hamstrings, sometimes don't. After this workout I spin for 45 minutes high cadence light resistance and feel great afterwards.
My legs are not noticeably larger, but the watts that I can put out for a sustained time are higher, thus I am faster.