I have some thoughts on this, having purchased and used one of original "Moto-X Caddies" when they came out a long time ago.
I hauled a Suzuki SP600 across the country on it a couple of times and then here and there after I reached my destination, but I didn't like it and eventually got rid of it. Perhaps the newer models are superior in performance, but I think a few problems still ring true with the newer models.
The first factor is your vehicle. I used mine on a '95 Dodge Ram 1500 pickup; what I consider to be a fairly "beefy" vehicle. I don't know what you drive, but I would seriously consider adding some air bags to the rear suspension. Even with the Dodge pickup, I had to add an extra leaf spring to the rear suspension to keep the vehicle level when the bike was on the back. Before I added the extra spring, when I drove at night, my headlight beams were pointing upwards to the point where it was actually unsafe. No matter what you drive, you can pretty much be assured that when you hang 400+ pounds on one of these carriers that's 2-3 feet away from your bumper, your stock rear suspension is going to sag, and probably quite a bit.
My factory-supplied 2" hitch receiver had, I believe, a rated tongue weight capacity of 500 pounds and that's pretty standard although a lot now have a rating of 750 pounds.
There's been some debate about this, but it only makes sense to me that when a 400+ pound bike is hanging a couple of feet (basically on a fulcrum) off this receiver hitch, that downward force is automatically multiplied and probably extremely multiplied when going over even slight bumps as the bike moves up and down due to the forces of gravity. How much this additional downward force is may never be known, but common sense tells me it's probably quite a bit. So, the bike/carrier might not exceed the tongue limits at rest, but what about while the vehicle is moving and the thing is bouncing up and down?
I would strongly recommend you crawl under your vehicle and see how your hitch receiver is attached. Mine was bolted on: some are welded on. If it's simply bolted on, I would recommend getting some additional welding done on it to strengthen it. Corrosion can take its toll on bolts and weaken them.
Any item that is fairly easily inserted into the 2" receiver is naturally going to have some slop to it. Balance a KLR on it and you're going to get a lot of up and down movement at the "ends" of the bike and it will flop around quite a bit. I solved this problem by having a local welding shop fabricate two brackets for me out of 2" angle iron that slid into the outside ends of the receiver hitch and then bolted to the rail the bike sat in, adding a huge amount of stability to the carrier because the rail was then supported not only in the middle, but also about a foot and a half on each side of that. But, nowadays a lot of receivers, especially on SUV's, are surrounded by the plastic bumper so this might not be an option.
There may be new designs now that eliminate this "slop," but even the tiniest amount of slop in the receiver fitting is going to be magnified by distance and the carrier and bike are going to seem like they're flopping all over the place due to the inherent play in the receiver "tube" itself. Maybe somebody has an answer for this slop. I always used a large bolt to attach the carrier to the receiver so I could tighten it down instead of just using a slip-in pin and that helped quite a bit.
Bottom line: like I said, I used one of these things quite a bit because it was either that or leave the bike behind, but whenever I used it, I was always VERY aware that it was back there and was cognizant of the fact that if it ever fell off and hit another vehicle, it wouldn't be good. I even wrapped a large log chain around both the carrier and the frame of the bike, then to a portion of my truck frame well away from the receiver so if the receiver or carrier did fail, at least the thing would be dragging behind my vehicle and not flying down the road untethered. I guess that was my own version of the "safety chains" that are required on any kind of trailer, etc.
I can't remember how much that old SP600 weighed, but I'm sure it was less than a KLR. No matter what the ads/receiver/tongue weight capacities say, I still believe these things are more for dirt bikes in the 300-pound range and hauling a KLR on one is kind of pushing the limits although it theoretically falls under the max weight limit stated.
Anyway, not trying to talk you out of it or anything, but I've been there and done that and those are my thoughts. In the discussions I've had about them, neither I nor anybody else has ever heard of an instance in which one of these things have failed, but they can be very unnerving with, for me at least, just that overall feeling that "this just doesn't seem like a very good idea."
Also be aware that depending on what you drive, a bike as big as the KLR sitting sideways can obscure your tail lights and depending on how your state requires them to be displayed, can obscure the view of your rear license plate. Since I was traveling through several states, most of which required a rear license plate, I had to bolt my plate to the carrier and even then it wasn't illuminated at night.
Last edited by planalp; 03-09-2011 at 09:16 AM.