We receive a lot of questions on why we do not recommend installing bicycle hitch and roof racks on RVs, Towed Vehicles or Trailers. Read below on why;
Trailers have two problems that will either cause the bike to dislodge from the mounting position or the rack to crack/fail/bend prematurely. Racks that would live a long, happy life on a passenger car are in for a tough, short life on a trailer.
Trailers are not designed to carry occupants during travel, so the suspension is cheap to save cost. Undamped leaf springs are not like the suspension in a passenger vehicle that comes with well tuned shocks and struts for passenger comfort and vehicle handling. The vibration that travels through the suspension and into the frame (or hitch on the trailer) is magnitudes worse than the vibration in a passenger car or truck. Vibration is a main consideration in bike rack design, and the vibration that travels into the hitch racks is a minimum of 4x that of a standard vehicle. We had a customer purchase a hitch rack from us two years ago for use on a trailer on a trip from New York to Alaska. When they reached Minnesota, the outer tray had failed and they lost the bike. The steel tube that supports the wheel tray to the rack frame had cracked and separated. We had never seen such a failure, and in reviewing the incident, learned about the trailer and denied their claim, they never read the instructions. The customer said “it worked fine when we left”. Excessive vibration from the trailer compromised the rack leading to the failure, in this case, it took about 1,500 miles to failure.
Trailers can get airborne. If you drive over railroad tracks, the vehicle absorbs this while the trailer does not. When the trailer “lands”, it can put a load up to 8 Gs of force on the rack and hitch. Imagine a 50 lb rack, with two 40 lb bikes. At 8 Gs, that is 1,040 lbs of force on the rack. Now imagine 6 or 7 adults standing on the rack, that is a lot of force.
All racks fold up and down. If you use a rack on a trailer, the round holes that a pin slides through will begin to ovalize and the rack will develop a lot of slop that cannot be removed. Once you use a rack on a trailer, it is forever compromised and its life has been shortened.
RVs have proper suspension, so this is not an issue. The problem with RVs is the length from the rear axle to the hitch. On passenger cars and trucks, this averages about 32”. On RVs, this can be up to 12 feet. This distance from the rear axle to the hitch is a lever arm and the longer the lever arm, the greater the force on the hitch rack. On a standard 50 lb hitch rack with two 40 lb bikes (50 + 40 + 40) is 130 lbs of rack and bikes. We test to 4Gs, so the rack can withstand this force of 520 lbs. If the rack is extended to 96” (3 times greater than 32”), the rack could experience loads up to 9 times greater. Imagine the 50lb rack with two 40 lb bikes, the load on the rack could reach 4,600 lbs of force. This is equivalent to parking a car on the hitch rack.
We have 30 years of design, testing & customer feedback (both positive and negative) and have learned what works and what does not. There are some dubious sellers of bike racks that have no idea of the added strains on racks in the above situations and do not limit use on RVs or Trailers. We have purchased some of these for testing, and the results were scary. Many of these companies have no phone # and do not respond to emails, so there is zero recourse. If you have light bikes and drive at 20mph, a rack on an RV or Trailer is fine. If you drive like the rest of us, the rack will eventually fail, it’s just a matter of when and how bad.