Joined: Feb 2012
Posts: 19,320
Likes: 5,427
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
"if I peddle even moderately hard, the peddle crank slips"
This description isn't one that I associate with a worn BB. Loose BB in shell, loose arm on BB axle, worn chain and/or rear cogs, shifting set up/adjustments are some the vastly more common reasons why bit seems that the pedals are "slipping" forward.
Before spending $ do your homework on why you have this problem. Also begin the education of what your bike has, component wise. Andy
__________________
AndrewRStewart