Paw Print Trailers

[pawprint]

rubber torsion vs. leaf spring on trailer

Hello again. I will offer my personal opinion on this subject backed up by proffesional and personal experiences. To start let's answer why does the rubber torsion axle exist?.Leaf sprung axles have been around since the horse drawn wagon era(s) of Europe and the US. Leaf sprung axles in the proper weight rating are bullet proof under the right conditions,i.e. pavement/concrete for which they were designed. The military has used them successfully around the globe under extreme conditions so why reinvent the wheel (axle)?.. smoother ride... The rubber torsion axle was developed in this country by Henschen axles in 1949, they are still in business and build a quality product with some inovative features.(see Henschen axles.com) Dexter axles which the "Paw Print" and other high quality trailers like the fabulous "Tent-trax" uses also builds what I believe to be the finest rubber torsion product available.(see Dexter axle.com)I should mention for liability's sake that there are a host of other manufacturers building quality products out there.The concept of the rubber torsion axle is quite simple but provides the following complex features. 1. proggresive spring rate (dampening) so no shocks are required. As the axle load is increased by weight or "bump-load" so is the pressure against the rubber stuffing increasing dampening and thereby increasing load rating. 2. Rubber torsion axles allow by design independant suspension. 3. Ease of installation (less labor to install) 4. Silent operation 5. Higher (or lower) ground clearence by adjusting the "torque arm" start angle.

With all this said there are some draw backs to rubber torsion....1. More expensive 2. Should you bend an axle beam or spindle the entire axle would be replaced. I am out of space and will add another post reply to finish

 

[pawprint]

rubber torsion vs. leaf spring cont.

3. Overloading can cause the "Torque arm" to over rotate and stop in the next and very unwanted position. I would suggest that the weight rating of any rubber torsion axle application be thought through carefully. It should be no suprise that the tent trax and paw print brands (and others) have selected a particular weight rating on their torsion axles. At Paw Print we use the 1400 or 1600 lb GVW axle because if we were to use a 3500 lb axle on a small trailer weighing only 560lbs the axle would never travel unless we had a load of about 1500lbs in addition to the trailer to start with. Now to answer the questions. Wash board coditions: these conditions can add stress to any axle system, rubber torsion is best suited for this application due to independant progressive spring rates and less moving parts. Axle failure on wash board conditions is NOT due to over heating of the rubber.It IS due to over loading of the axle due to weight. I should add to this statement that some axle brands are of lesser quality and could fail for a host of reasons I won't address here. I would suggest that the "Baja Axle failure" was due to overloading not heat. Also from a technical view, a Dexter # 10 2200-3500GVW standard torsion axle requires 80,000 psi to press the stub axle and torque arm form the torque tube and rubber stuffing. From a personal testing point of view I have towed under the same conditions and had no failures.

 

[pawprint]

Paw Print cont. # 3

4. Shocks will not help and are not recommened by any manufacturer of torsion axles that I'm aware of.

Unfortunately most trailer designs are usually comprised of ideas that solve a problem. Most trailer manufactures interested in a quality design and product do not come by this without tremendous research and development of the products available to build these units with. Remember you get what you pay for and this is especially true in the trailer business. Many excellent products are available as "surplus goods" out there and can be adapted to good use for expedition purposes but most were designed to be used by government/military vehicles and are heavy. If you have not towed off road you will be suprised by the new driving strategies you will invent as you go.....may be were on to a whole new sport.......of road trailer towing competitions............................