Single-wheel motorcycle trailer features igus bearings

When motorcycle enthusiast and entrepreneur Eric Debenham formed his company Mono-Trail to develop a single-wheel motorcycle trailer, his main aim was to create a design that looked as sleek as his bike. He also wanted the trailer to have full suspension but without the penalty of additional weight - hence he contacted igus UK for advice on plastic bearings.

Debenham states: "We all spend a fortune on panniers, top boxes and tank bags - just so we can use our bikes more and do some touring. They never seem to hold enough though, and then there is all the extra weight high up on the bike which makes it feel awful to ride." When he spotted a single-wheel motorcycle trailer on the back of a bike a few years ago Debenham gasped and said: "This looks the business!"

What appealed to him was the idea of having no luggage piled on the top of his bike and, instead, having a trailer that followed the angle of the bike through corners; also the trailer could be no wider than the bike, so the combination would still be able to filter through traffic jams. The particular design he had seen could have done with a better, more attractive, quick-release hitch and looked rather ugly when compared to the slick sports bike that was pulling it. One thing lead to another and Mono-Trail was born.

Bearing advice

Matt Aldridge of igus UK takes up the story: "Initially Eric contacted us for advice on the link arms in the suspension system of the trailer. He had evaluated all sorts of designs but had not achieved the desired solution. We sent him some samples of the standard igubal EGZM-08-60 double-joint pivoting bearings and, intrigued by his application, shortly after I went to visit him."

Positioned adjacent to the wheel, these bearings are subjected to salt water, dirt and debris. The original design used a nut and bolt assembly, which was heavy and caused the ball to swell. In addition, the tie bar needed a grease nipple at either end since, every 1000 miles or so, it had to be greased - which was not ideal for a road trip across Europe!

The spherical balls at either end of the link arm in the igubal double joint pivoting bearings are engineered to run dry, which means they self-lubricate and are dirt-repellent and rugged. In addition, without the need for lubricants or maintenance, grease nipples are eliminated from the design entirely. The plastic also helps to dampen the suspension and, with a motorbike trailer, every gram counts, which is another point in favour of the lightweight igubal bearings.

Pivot bearings

"While I was there," continues Aldridge, "I noticed that Eric was using ball bearings at the pivot point of the trailer's suspension." Here the load bearing capacity is quite low and there is not a full rotation of the ball. This area is also prone to water and dirt. iglidur P bearings solved the problem, being economical and non-swelling in the presence of water. Further igus bearings are used in the main lid, this time two iglidur G bearings, which help to create a quality feel on closing. Two more are similarly used in the glove box and another to counteract the flex in the draw bar.

"Nearly three years of design and testing later, we have launched the TourMAX," says Debenham. "A great-looking, high-quality, fully road legal, single-wheel trailer that will sit on the back of a bike and will swallow all your stuff securely and even pull a crowd of admirers wherever you go. The suspension has been completely redesigned nine times now but at last we have created a system that is simple, robust and maintenance-free. The ride is actually much better than we had hoped for so we are really pleased with this."

The TourMAX is the first in a range of single-wheel motorcycle trailers Mono-Trail has in development. The next adventure is a trailer designed specifically for carrying pets.

For more information, call igus UK directly on +44 (0)1604 677240 or visit the website at: www.igus.co.uk.