basically what enduramill says - to really answer your question we need more info re type of riding and intensity of your strength workouts.
the basic answer would be to ride/lift on alternate days, but what will matter the most is looking at the intensity and volume of your training. this means that either your strength days will be light and not really strength workouts but assistance workouts, or you will have to make two of your rides easy or recovery rides. the determining factor on how much you can do always comes down to the amount of recovery available between your workouts.
Also keep in mind that what one has to look at their total accumulated volume during their waking hours of physical activity. Everything we do from unloading the pickup truck of fire wood to shovelling out your drive way is physical activity. This on top of weight training sessions and bike works outs adds up . Even more so if you are doing every bike ride hard.
