I can recommend two campgrounds on Corsica
Located right between Porto-Vecchio and Calvi, it is way
off the beaten track, and thus extremely secluded and quiet. You can park your motorcycle right next to your tent, last time I've been there (2005) the bathroom facilities were old-ish but very clean, there's plenty of trees and very secluded spots where you can camp. Five minute walk to a very quiet and secluded beach (Rondinara Bay), water and beach are very clean (except for occasional cows on the beach, not kidding). So far, this one was our favorite one on Corsica.
Camping la Pinède
Right at the gates of Calvi but still outside of town. Very big, swimming pool, five minute walk to the beach, ten to fifteen minutes to the city center of Calvi. Incredible view of the Calvi citadelle, quiet enough. Bikes can be parked right next to the tent (at least that was the case in 2005). Bathroom facilities were somewhere between ok and ewwwwww, however they were renovating some of them already - might be a lot better now. As of 2005 lots of ants though, and there's a train track between the campground and the beach, with a train that runs every two to three hours during the day. The view of Calvi and its citadelle is incredible though, have I mentioned that?
Reservations might be necessary, dunno. If you want I can post some photos later today, just let me know.
"Life is not a journey to the grave with the intention of arriving safely in one pretty and well preserved piece, but to skid across the line broadside, thoroughly used up, worn out, leaking oil, shouting GERONIMO!"