That's the same system as the stock Hobie 20 system. As other's have said, it's not a bad system, but I eventually went away from it.
First, several posters have suggested adding a block to the rotation bar to reduce friction. In my experience, I have found that adding a block usually does more harm than good. The reason is that when the rotator switches from side to side, the block has a tendency to twist which causes more friction than just going straight through the bar.
There were a few reasons that I eventually went away from the double sided system. The first is that every double sided system has a problem in that the line can get pulled all to one side. This means that there may be situations where the crew would have to crawl down to the leeward side to make an adjustment - not always possible.
The second reason is similar to the first, and it is that I generally found that I didn't like having to make the adjustment from out on the hull. I guess if you think you will be fine tuning the rotation upwind from out on the trapeze, you would want this system, but I never found that to be the case, too many other things to do. I prefered that either myself or the crew could come to the center of the boat to make all the adjustments quickly (rotator, downhaul, outhaul, jib luff) and then move to another position if necessary.
I eventually ended up modifying the system so that it cleated on the boom rather than out on the hull. One last advantage to cleating on the boom is that if there is a lot of load on the rotator (from a positive mast rotation system for example) the crew can put one hand on the rotator and the other on the rotator line and pull both in to easily bring in the rotation.
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