Joined: Feb 2012
Posts: 19,381
Likes: 5,528
From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
Any 39T ring might not be of the same bolt pattern or have the shifting aids (lift pins, ramps, shift gates...). I take it your LBS hasn't been tried yet? Andy