Can I attach a 4th Add-on (to make a 5-bike system)?January 1, 2021 A Can I attach a 4th Add-on (to make a 5-bike system)?UPDATED SEPTEMBER 2023We advise against it because it extends beyond DOT regulations and it would put excessive leverage and strain on the vehicle’s hitch and rack components.We would not warranty this usage. Category: Specs and Fitment Permalink Back to Top