Joined: Feb 2012
Posts: 19,288
Likes: 5,381
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
Bikes are full of M5 fittings, like water bottle mounts or fender mounts. It seems to me that if the anchor bolt is still in place and only a nut is needed one might be able to thread the bolt into a known fitting on the frame to confirm. FWIW I think the anchor bolt is a M5 too. Andy.