Fwiw, and I am not the best runner, I have found that cycling has drastically improved my running from a cardio/breathing standpoint. I think it is because my distances for running aren't far (yet) but I love biking for 40-50 miles on the weekend and I also enjoy sprinting my 20 mile rides during the week. I would think you can replace your recovery runs with the cycling and be just fine. So long as your bike fits and you aren't feeling any aggrevation in your knees or tendons, injury shouldn't be a huge concern. Cycling is much less severe on your body than running.
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2008 Ruby Elite
2012 Tricross Elite