We were recently contacted by a customer having difficulties using their J92s mainsheet system.
The existing configuration had used two lots of purchase systems (shown below) , this was resulting in lots of friction and requiring the user to pull a whole load of line to exert any force on the main.
We upgraded the mainsheet system to a Harken fine tune system, which allows much greater control over mainsail trim. The course section (6:1) is used to trim the main to 90% trim. The 4:1 fine tune then exerts a 24:1 force on the mainsheet which is far greater than the multiple purchase on one line used before
The fine tune purchase also allows for much smaller sail adjustments in the gusts, small sheet ease and trimming can be carried out effortlessly
We also removed the traveller car and carried out a ball bearing change to improve the use to the car.