I looked up the Schwinn web site and the "Racer" is a 700c wheel flat bar single speed with a coaster brake. The description of the crank just says Schwinn Alloy" and specifies a "cartridge" bottom bracket. Make and model of both aren't given. From the picture it appears to be a square taper crank and bb and very likely English threaded. Any suitable length Shimano UN-XX cartridge bottom bracket should work. The dealer's $70 estimate certainly includes installation but the bb itself can be had for $30 or less if you have the tools and knowledge to install it.