Commentary on Aluminum Cycle Carriers
Section I — Background:
The cycle carriers advertised as aircraft grade aluminum actually use traditional steel for the receiver tube (the main structural member: square tubing that runs into the hitch receiver).
Section II — Engineering, Materials & Comments:
- The Ladder Assembly(channel) is typically made from 6000 series aluminum.
- Advantages of Aluminum:
Typical weight savings of a properly designed aluminum product vs steel is 1/3. The tray typically weighs 25 lbs so the weight savings can be 8 lbs. Actual Motorcycleracks brand weight for example: Model 3C6-19-S w/60″ ramp=73 lbs.
- Aluminum does not corrode as early as steel with most environments. Road salt is highly corrosive and will attack painted steel products more readily than aluminum.
- Disadvantages of Aluminum:
Aluminum is not a very tough material as it is very unforgiving! Aluminum is expensive, must be highly engineered, and is very complex to manufacture. Notice how long it has taken autos to have components made of this material? Do you honestly believe a cycle carrier selling for $190 and the company popped up yesterday has had extensive engineering completed and strict quality control in every step of the manufacture of it?
- Aluminum can become brittle as it has a very low ductility compared to plain carbon steel. Aluminum has low fracture toughness and poor fatigue strength, also.
- If aluminum is subject to cyclic/fatigue loading (as the carrier tray is: road vibration/shock and the hauling vehicle turning corners) and is overloaded even once, a very sudden fracture can occur from any notch or area of poor workmanship. Have you ever seen the modern aluminum snow mobile trailers severely damaged or broken in half from hauling too much weight? Aluminum fractures without warning! Steel bends a considerable amount before failure in almost all cases.
Section III — Heat Trea tment:
- Heat treatment is lost when forming or welding. To produce the “ladder shape” of the tray, the 6061 aluminum would have to be heated treated after welding to restore its tensile strength properties. This heat from welding would result in the loss of strength properties. This uneven heating to fabricate it likely results in a tray with unknown strength properties.
Don’t risk your cycle to an aluminum experiment, go with tried and proven material; STEEL!!