What size bikes can the rack handle?September 9, 2020The bike rack can be used with a wheelbase of 56″ with wheel sizes from 12″ to 29″, and up to a 5″ wide tire with no adapters needed. See the no-tools tire size adjustment in action:Here is an image of the bike size range dimensions. Quik Rack Mach2 with Add-Ons: Loaded for vacation