No, you don't,b but you've got to have another pseron to help you. After unsuccessful attempts at fitting them by myself, I had my wife pull with the other winch on a line passed through the "Wincher" whilst I slowly pushed it on the rim of the winch I was trying to equip with it. It worked very nicely. You've got to get the exact size of "Winchere" for your size of winch; if too small, it won't go on, if too big, it will slip...
john
great I have had them for 3 years,used a tyer lever and washing up liquid to get them on.
by the way it took me ages to figure it out that the rope is held by the underside if the ruber self tailers not the grove, so put enough turns on the winch
Good luck
Dave
Have said it all!. The groove is for cleating off the line if it doesn't have a clutch, which are essential to sort out riding turns anyway. I have seen them fitted upside down - all that effort just to get blue rubber fenders on your winches!. They should have the chamfered, ribbed surface face down of course!
Yes, they work really well. So well in fact that I can't help wondering why they didn't make the winches that shape in the first place since it would have required no extra engineering.
.. on the new boat I would say that ST's win in the fact that the baler shows you exactly where the tail will fall whereas the wincher determines this by the size of the rope and therefore where the tail is released once the required friction is attained. On the last boat this was straight down the companionway for the main halyard but onto the side deck for the reefing pennants. Winchers do require a straight fall off the top turn to work one handed.