I was just looking at this book in a bookstore:

http://www.bikeforlifebook.com/homepage.asp

There's a chapter that I think was titled "rolling relationships" which gives advice about your exact problem, which they refer to as "CWS" or cycling widow(er) syndrome. It's evidently a common problem for racers. I didn't read much, but it looked well informed and I almost bought it (but there was a line ).

I also want to say good luck to you. This cannot be easy. I can see both sides, and you will have to work out a compromise. Each of you will have to give a little if you want your marriage to move forward.