FloJo touched on something that you might consider and that is that cycling isn't the best way to build strength in a short period of time. Yes, climbs will help but you are still basically doing a workout of high reps and low resistance which is an endurance type exercise formula (somewhat true of the plyometrics, but less so). If you are looking for strength increases then I would get with a knowledgable physical therapist and explain what you want and they can help you work a training schedule out that will allow you to ride lots but still spend some time in the gym with squats, cleans, leg press (will be high weight, low reps).
One thing to understand is that you will probably train for strength gains and then once those are reached work on endurance of that strength over time.