------------Wimberley Sidekick and retaining ring from Review on BhPhotoVideo

I'm a wildlife photographer so I bought this, along with a Gitzo 3530LSV and a Wimberley Sidekick to hold a Canon 500mm f/4 on a Canon 20D. The first time set the whole rig up, I set out to walk the trails. I have always been leery about throwing a $6,500 rig over my shoulder, but the whole system looked to be pretty solid; so I carefully set off. After a couple of steps, I felt some motion and immediately stopped to inspect the rig only to find that the ballhead had SEPARATED from the base – almost falling off with my 500mm lens! Fortunately, I noticed this before anything really bad happened. After pulling the two pieces apart, I found that the base was attached to the ballhead by nothing more than a wire snap ring (round in profile). I’m no engineer, but it seems obvious to me that a round wire snap ring in a square slot can easily be pushed off with even a little upward twisting motion. Needless to say, I was very disappointed; but rather than sending it back, I decided to fix it. I improved the design by obtaining a standard #5100-177 retaining ring from a local bearing shop (which cost less than $1.00); ground it down to the same size as the original ring and installed it in the slot – along with thin shim under the brass friction collar to make up for the slight extra movement. Now I have a square snap ring in a square slot; the way I think it should be. I reinstalled the sidekick and camera/lens (about 9-10 lbs worth) and turned the whole thing upside-down twisting and turning to try to separate it, but there’s no way it’ll separate anymore - now that there’s a square snap ring in there. I am much more confident in the ballhead now; but I am really disappointed that I had to modify it the way I did. Whatever you do, DO NOT carry a large expensive lens (or anything of value) over your shoulder with the stock ballhead; if you decide to - make ABSOLUTELY CERTAIN you securely lock the friction collar down tightly (the small knob beside the big one). Better yet, replace the wire retaining ring as I did. Once it is modified you should have no more problems with separation, regardless of how you handle it.