ABOVE The trailer (in its V2.2 stage) enjoying a day off in the Florida Keys.
The concept of carrying a trailer with us isn’t exactly ideal when considering some of the locations we will be visiting. A trailer adds extra weight and bulk to the motorcycle which certainly doesn’t help with handling. Furthermore, the trailer is an extra piece of equipment that we must be aware of and maintain.
With that being said, we also needed a way to effectively transport our paragliding gear with us as we go. We considered the idea of shipping our gear to ourselves but ultimately decided that would become expensive and puts our gear at risk to be either stolen or lost. It would also limit our flying to places where we could ship, which would be predetermined flying sites. We would like to be able to fly when and where we want if we feel the selected site is safe, conditions are good, and we’re not impinging on the property of others. We also considered large top boxes for the bikes. Not a terrible option, however that limits us as far as room goes and the top box would be quite large itself and all the weight would be as high as it could possibly get. A sidecar was the last consideration. We contacted some people who run sidecars looking for advice and asking questions, but ultimately decided that building and fitting a sidecar on one of our motorcycles would be time-consuming and with the potential of not being strong or stable enough due to the Elefant’s aluminum subframes. Also it would give us a width that we didn’t particularly want for going through city traffic or small roads in desolate areas.
This led us to the idea of a trailer. We considered two main kinds, two wheeled trailers (very similar to a trailer for a car) and single wheel trailers (commonly found on bicycles). Whatever we chose had to be very versatile. The trailer would have to withstand rough roads with major potholes and washouts, and be thin enough to weasel through traffic. The other major issue was the hitch system. The Elefant’s sub-frames, while stout enough with a little bracing to hold a set of panniers and a top box, just were not designed well enough or strong enough to hold up to having a hitch attached to them. Because of this we wanted to mount the hitch near the center of the bike, right behind the foot pegs. Our first design saw us going with a single wheel trailer.
Here is V1.0 of our trailer on its first day of testing. The bike had just been finished and was still missing pieces. (December 2016)
We initially chose the single wheel design for numerous reasons, the most important being potential handling and ease of tire/tube issues. We would run the same 17″ rear tire as the bikes. The trailer mounting system uses two axes to pivot, just like a u-joint, allowing the trailer to follow the same lean angle as the bike through its range of motion. The trailer leans with the bike so that any sort of road undulation would not be fed in through the bike. The major disadvantage to this is that while stopped, not only do you need to support the weight of the bike, but the trailer too. The advantages are that the trailer has one wheel and one suspension on the back making it more affordable to produce and a bit easier to tune suspension-wise. We designed it to have a good amount of travel using dirt-bike style suspension.
It turns out that while the single wheel trailer did work, there were a few unforeseen issues that came up. The biggest being the geometry of the front hitch design, because our front swingarm is so long, when you turn the bike the trailer isn’t centered any longer. This causes the front of the trailer to want to fall on the ground, the only thing holding it up is the lean of the bike to the inside of the corner. When stopped like this the bike must be leaned in at an awkward angle. This also makes slow speed maneuvering very difficult as every time you turn you not only need to account for the bike wheels and the terrain but the angle of the trailer behind you. Finally the front swingarm was also not quite strong enough so that when going down the road we had too much wobble from the trailer input through the bike causing a dangerous situation at speed. This design certainly was not going to work. We’ll call this trailer design V1.0.
Since V1.0 certainly was not going to work, on to V2.0 of our trailer. We decided that the only way we were going to make the trailer work for us is with 2 wheels. We didn’t want to go with 2 wheels due to width and rough road issues but there was nothing we could do. We took about 6 hours to draw out designs and come up with a dual-wheel single swingarm with 1 shock. This allowed us to have 2 wheels, great cornering stability and easy tunability of the shock. Unfortunately this new design required us to trash a lot of our previous brackets and whip up some new ones. We ended up using our stock Boge shock that was in decent shape to go along with our revamped bracketry. This redesign was thus dubbed V2.2. We also moved the wheels forward from the previous design to offload some of the weight from the bike as it was getting to be a bit heavy. The other major modification was that the bike now needed to lean but the trailer would not. We cut out our front swingarm pivot near the trailer and basically added a heavy duty pivot that utilizes a spindle and bearings to allow for this movement. We used some old Legos to mock everything up and decided that new rotational pivot should be hard-mounted to the swingarm and the original vertical pivot should stay the same on the trailer. This design allowed the bike to move unhindered without trailer load effects while turning at slow speeds. Read more about it in this journal entry.
V2.2 of our trailer “frolicking in Florida.” We put about 1000 miles on the trailer over the two weeks we were in the Sunshine State. (February 2017)
Version 2.2, while in working condition, had some characteristics that we still didn’t really like while riding it around Florida. Because the wheels were suspended on the same beam, any small bumps that we didn’t hit perfectly straight on would still shake the bike around some as the trailer was forced to tilt side to side. There remained some considerable weight on the bike as the wheels were still a ways back due to most of the revamped suspension sticking out over 9″ to the rear of the trailer. Finally, before we even left for Florida we were finding that our door latch was not staying latched, so we had to modify our latching system a bit inside the trailer. We were left with a trailer that worked, but wasn’t terribly fun to haul around. We were in a position deciding if we should just skip the trailer completely because it was such a pain to ride with.
Once back from Florida we spent a serious amount of time thinking about our situation, at least 10 minutes. We decided that we have enough time and money wrapped up in the trailer and if we wanted to continue to paraglide we would need the trailer to work better. Enter V3.0. We completely ripped off the rear suspension and started from scratch again. We decided that we would have 2 swingarms facing forward from the rear of the trailer, 1 for each wheel, thus allowing independent suspension. We would use the stock Boge shocks from our Elefants for the suspension and leave the front swingarm as is.
V3.0 of our trailer, unloaded so the suspension is a bit tall. (March 2017)
Version 3.0 worked wonders as far as handling on the bike. Low speed bumps and potholes that were hit off center were great with little to no feedback through to the motorcycle. At this point we thought we were on to something that could be made to work for us. The only real issue was that one of the Boge shocks had a bad seal and, of course, we could not locate the right seal to replace it. Also the spring rates were a bit too stiff for our little trailer. So, on to V3.1. While the geometry of everything worked well the trailer was not being dampened properly and was too “springy.” This led to dangerous situations at high speed. Our next bet was to replace our stock Boge shocks with some cheap RFY shocks off eBay made for older UJM standard bikes. We spent some time rebuilding the shocks but they just were not up to the task of proper damping and we were having trouble finding springs that would work. V3.1 just wasn’t going to work for us.
Finally we settled on some Yamaha WR400 shocks as they could be had decently cheap on eBay and were easy enough to rebuild and parts were available. Enter V3.2. We received 2 shocks, one was in decent shape but needed a new seal and a good cleaning, the other was different in a few ways and in very very bad shape. We ended up buying one more used shock that was the same as the first and also in good shape. Once the two similar shocks were rebuilt, we fabricated some new brackets and set our geometry up. V3.3 worked fantastically! The shocks themselves were able to be tuned with the compression and rebound adjustment so that on the highway the shocks were very stiff and off-road they could be a little more pliable. After some road testing we decided that this would be our final setup for the big trip. Overall, we’re pretty pleased with the design.
Now, enough of all this suspension blabbing, the trailer itself is a bit unique as it was built then rebuilt a couple times until we ended up with a product that would work for us. The front top box is separated from the main compartment so that not all of our gear gets wet in the rain. The main compartment, of course, holds our paragliders, a bunch of our camping gear, a separate battery, charge controller, solar panel, and a few other goodies. The trailer hauls all our spare parts for the bikes and has its own brake and turn signal lights. It’s designed to be a stand alone system so that when we are in camp for some time, we can use the electrical power off the trailer for charging our gear, such as our communicators and computer. We can also recharge this battery with our solar panel so we don’t need to run our bikes to create power. However, the trailer will also charge off the bike while going down the road.
V3.3 of our trailer without fenders and mudflaps. Sneak peek into our trailer, cat not included. (April 2017)
We also added some mud guards and fenders to the trailer to help with road spray and mud and added a flap door to keep some of the water our of our not so waterproof, waterproof main door latch. The trailer is large enough to hold all of our paragliding gear and waterproof enough to keep it dry (very important). Most everything else is in a top box made from an old Pelican case and some Journey Rider panniers.
Overall, with our new trailer design, we think that we can comfortably and safely ride to and through the places we are planning on visiting.