Joined: Feb 2012
Posts: 19,353
Likes: 5,471
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
Well, the rightest thing to do is to make your best judgment then install said BB. Now you can check the actual chainline and other dimensions (like crank arm or ring clearance with frame or "Q" factor) and if needed remove the tester BB and install the now "corrected" size. Anything else is just assuming. Andy.