Masthead sheaves

The best of the season to everyone.

This fall, after putting the boat away for the winter, I discovered that the axle for the main halyard sheave had broken at the stem attached to the tab. The sheave bore is slightly out of round indicating it has been unserviced for quite a while.The seats for the axle are in good shape.
Rigrite sells the axle assembly and the replacement sheave. This sheave is made for a wire/rope halyard. Does anyone know if I can increase the diameter of the sheave from 2.5 inches to 3.0 inches without causing a space issue in the masthead assembly? I am going to replace the halyard with all rope and I think a sheave from Annapois Performance Sailing ( a Ronstan sheave RF 2855) would better suit all rope.

thanks

Steve Murray
E35 III 222
Charlottetown, PEI

Another Possibility

Steve,

We replaced the sheaves and spindles on our 35-3 last year. Rather than going through rigrite, we had them all fabricated locally, and they came out OK (on the 3rd try, but thats another story).

We left our sheave size alone... I don't recall if there was enough room for a larger size on the "back" end of the slot, but I do remember there is nothing you can do with the width... its a very fine tolerance in there... you might be able to run 7/16" rope, but we went with "hi-tech" 3/8" to be safe.

- Cory

I replaced my masthead sheaves last winter. I used Grahaurer sheaves which matched the original sheaves in width. They worked great this season. Guido machined new pins for these sheaves that allowed me to extend the pin out both sides of the mast with cotter pins on both sides. This makes it much easier to remove the sheaves for maintenance. The sheaves were about 60 dollars each and he didn't charge for the stainless 3/8" pins.