Torsion axles and tires
I’ve been asked why we use torsion axles in our Gnome Homes.
First, just a bit on the design. Torsion axles are fabricated with a rotated square steel bar inside a steel tube. The hollows created by the rotated inner bar are filled with rubber cords. The inner bar is connected to one end of an arm. The spindle and hub are mounted on the other end of the arm. The drawing below shows the inside end of the tube with a clear view of the square bar and cords.
When the wheel hub is loaded the inside bar compresses the rubber cords. The cords act as a shock absorber. This design works quite well.
The advantage of this design is that the axles are compact, independent and simple. Compactness provides 1 1/2” additional clearance where the axles are mounted. There is 3 1/2” of extra clearance between the axles. Torsion axles are much less likely to get hung up on rough ground vs. axles with leaf springs.
The simple design makes them easier to install and offers a lot less lifetime maintenance. No need for spring and shackle checks and adjustments. The independent action provides a smoother ride, greater stability, and better control. Simpler and safer is almost always better. Less expensive, long life is a bonus.
No-maintenance torsion axles are part of the Gnome Homes “hook up and go” lifestyle advantage.
Terry was kind enough to join us at the Calgary Outdoor Adventure Show. Our shared past (farm boys) had us talking about trailer tires, and tire rot. Trailer tires usually do not get enough miles on them to wear out, they rot. Exposure to oxygen causes the tires to rot over time. Oxygen is on the inside and outside of the tire, so your tires get attacked from all sides and deteriorate over time.
UV rays and Ozone also accelerate tire rot. Adding a layer of UV protection will help protect tires, as will covering the tires when not in use. Many tire shine products do not protect against UV, and may remove the wax that protects against oxygen. It’s best to use a product that protects against UV and doesn’t strip off the compounds. If your tires are graying, you should have your tires checked. If they are cracking, you may need to have them replaced.
Rot accelerates with temperature. It is important to keep tires inflated properly, especially if you have smaller 12” or 13” tires. One can visually check the contact patch properly inflated tires make with the road surface. Tires flatten out at speed. At speed, underinflated tires form a donut shaped oval instead of full contact. Heat goes up and safety goes down.
Tire manufacturers put compounds in the rubber to help the tires resist rot. The best way to increase the life of your tires is to use them. The action of proper tire flexing causes the compounds to continually work to the surface and protect the tires. Get out and go somewhere! You’re caring for your tires.
Now let’s put the tires and the axle together. The wheel bearing becomes a very important component in this marriage. This is where the size of the tires becomes a factor. All else being equal, the wheel bearing on a 12” tire is going to be rotating 27% faster than a 14” tire. On a trip of 10,000 km (6000 miles) the 12” tires will make 1.3 million extra rotations. This is a lot of extra wear. The second factor is ease of maintenance. Wheel bearings need to be packed properly. This can be done by a handy DIY guy or at a shop. There are u-tube videos showing how to do this. Alternatively, avoid packing by installing Posi-Lube hubs. Simply lube with a grease gun once a year. The u-tube video is 46 seconds. Clean and easy is almost always better.
The insurance industry has reported that the number one RV insurance claim is due to tires. The number two claim is due to fires. NHTSA reported (2009?) that 51% of travel trailer fires were due to wheel bearings. Let’s eliminate some of these issues.
Durability and safety are the reasons why we only use 14” or 15” wheels with Posi-Lube hubs on Gnome Homes. A small premium is well worth the care-free service life of a full size tire. After all, it’s all about camping!