The new Transfer v2 models can each be expanded to carry an additional bike with the 1-Bike Add-On. Increase the capacity of your 1-Bike, 2-Bike, or 3-Bike rack to carry up to *4-bikes with all the features you expect at a price that&';s unexpected. FEATURES Automotive-grade 750 hour salt spray hardware Holds up to a 50" wheelbase bike (previously 47") Holds wheels 18"-29" (previously 20"-29") Holds tires up to 5" with accessory strap (previously 4.5") + better hook clearance for loading fat bikes