Upvote:6
Have never seen public bicycle parking at Narita, there maybe something for employees (though based on traffic on the roads leading to Narita, I am guessing employees go by train or bus).
The Narita Airport Hostel mentions bicycle parking, so perhaps something could be arranged through them, especially if you overnight before or after.
There is a baggage storage service available in both terminal 1 and 2 where you maybe able to leave your bike in its packing box, if the airline won't let you check in on the flight.
Or perhaps arrange to leave it wherever you are staying beforehand in Tokyo, then simply take the train to/from the airport for your week abroad.