There are a number or reasons someone may want this extra space.
Standard Trailer Hitch Receiver Tubes
Extenders come in many different lengths. These typically include 7″, 8″, 14″ and 18″ lengths. Keep in mind that technically the hitch tube will be physically longer than the rated length to account for the amount that disappears into the receiver when mounted.
Some models have multiple pin holes to select from multiple lengths. These are commonly referred to as adjustable hitch tube.
Using a Hitch Receiver Extender Tubes for Bike Racks and Cargo Carriers
A receiver tube extender may be needed for bike racks to clear a rear mounted spare tire or for a cargo carrier that may have oversized cargo a little too close to the back of the vehicle.
Using Hitch Tube Receiver Extender Tubes for Trailers
If you are towing a trailer, it can create a little more distance between the vehicle and a box trailer helping to prevent the front corners of the trailer from hitting the back of the vehicle on a tight turn. When used on pickup trucks, it can also help create enough distance for a pickup truck tailgate to open without hitting the trailer. Maker sure the trailer receiver tube you purchase is rated for towing trailers and is also it’s rated towing class can handle the weight of your loaded trailer.
No matter what the details, the main purpose of a trailer hitch receiver tube is to protect your vehicle from scratches, scuffs or dents and other types of damage caused from the gear behind it.
Dual Hitch Bicycle Receiver Extenders
Dual Hitch Bicycle Receiver Extenders permit the hitch to be used for two purposes. While the bottom can be used for towing a camper, boat or trailer, the upper tube can be used for carrying hitch accessories, a cargo carrier or a bike rack.
Truss Receiver Extenders
These are the longest of the extensions. They are typically available in lengths ranging from 21″ to 60″.
A brand that has gained a lot of attention is the SuperHitch Super Truss Receiver Extension. Unlike the smaller extensions, this model is available in eight lengths from 21″ to 60″. It can only be used with the company’s SuperHitch or SuperHitch Magnum hitch. Built for heavy duty, it “…can safely tow up to 14,000 lbs and 1,400 lbs tongue weight on a 21″ extension and 12,000 lbs and 1,200 lbs tongue weight on a 48″ extension.“