If you like spinning do this exercise
Spinning can lead to imbalances in leg muscles strength which can lead to sore knees and joints as one side of your leg pulls tighter than the other. A limited range of motion also means the entire leg is not working.
Ballet squats help strengthen the inner and outer muscles and offer a greater range of motion than spinning. Add this to your routine, particularly in the winter when you are doing more spinning.
Start off initially without weights and then graduate to light dumbells once you make progress.
Be conscious of your form (knees & posture), and make sure each rep is controlled.
Adding this exercise to a good stretching and core strength program will help avoid any imbalances due to spinning.

I cycle a lot (as in commuting) and my right side is totally off. Pilates helps but I’ll add this now, too. I love ballett excercises