Slipping Main Halyard

Of course the best way to get D12 to lock in a V type cleat is to give it a core, easily done by sliding in a length of the same rope in the area where it cleats, 2 min job, but essential to get a hollow core rope to cleat fast.

Hauling the sail up with the halyard running thru the cleat will quickly wear the cleat jaws. I make sure the halyard is running beside the cleat until the sail is up, then flip the rope into the jaws and finish pulling up the last inch or two. I have two clam cleats and a vectran halyard. If it's seriously windy I haul down on the cunno after hoisting the main, then let it off & re-tension the halyard. Stops the sail slipping down under cunno, but makes it a right nightmare dropping the main after sailing. I just hate those racks - I find them too fiddly. Next mast will probably have a halyard lock.

Hi
I had this issue last year after replacing the rope. I think the new rope just kills and old cleat so replace the cleat and you should be fine.
My old boat had a wire halyard and rack, worked really well.
Good luck.
Gordon

Like craigo says, was my plan. Nice strong H
Bummel lock splice with a mousing line through it to pull it down to the rack.

PS don't mind the sail coming down a bit when the Cunningham goes on ... So long as it goes back up again without me hauling on the halyard.☺

Disadvantage of a hook rack is the knot for the loop weakening the rope (most of us have plenty of strength in reserve though, so not really an issue). The knot for the loop needs to be able to pass through any holes in the mast for an internal halyard and/or allow enough travel so you can detach it, you don't want it getting jammed in the sheave at the top of the mast (it might be able to pass through the sheave easily, in which case you're ok).
Of course they offer pretty good repeatability, once the braid of the rope and the knots have settled, you know you are putting it in the same place every time.