You're doing far too much cycling to maintain your running at it's previous levels. When i started riding in my late 30's, it was due to my noticing I was not recovering from my running workouts. By substituting riding(to work, actually) on what had been easy run days, I was actually running faster than before. I did maintain the meat of my running work-long run, steady-state and tempo.

I went from running 45-60 mpw to riding 60-90 mpw and running 30-35.

You may also be finding that you're a better cyclist than runner.