Well, I figure you should see if it is one of the following root causes-
1. you are slowly falling out of love again and starting to view each other as adversaries and thus the tit for tat comparison to each others private time begins or-

2. She really loves you a lot and is very insecure about you when you are out riding as she believes it is a dangerous activity and so when you get back attacks you as a release for all that pent up worry. I would take her on a few rides (even if they are slow) until she is comfortable with how you ride and she sees that neither of you have been hit by a car in this case, or perhaps discuss her feelings and see how you can work it out.

By the way I am not a psychologist or a counselor, nor do I play one on TV but I have been happily married for 13 years and know that true heartfelt communication from both sides is rarely a waste. Anyway, those are my thoughts. With love comes understanding usually but when love is stale criticism runs rampant in my experience.

Me I commute by bike to get my daily fix and do long rides on the weekend. I also try to take the kids biking a few times a week (or something else to get them out of her hair periodically). I find if I work to make private time for her she doesn't mind doing it for me.