jib block sheave size

westmatt wrote: I think I'm going to replace the tired jib blocks on my Prindle - what would an appropriate sheave size be in the replacement?

thanks

For main blocks? What are you going for 6,7,8:1 ? They don't come in a lot of sizes so mainly it's matching the proper pulley size to the sheet you want to use. Smaller sheets and blocks are lighter and have less friction but harder on the hands.

The hot setup changed from traditional "Yale Light" thick sheets to something like Salsa Braid which doesn't absorb water, is very light, runs well, but can eat your wet hands.

Also smaller generally more expensive per foot.

It's the stock 2:1 - one block on the tramp (the one in question), and one at the jib clew. The block(s) at the jib clew are 29mm. Sheet is 8 mm.

-Matt

OK Jib block. If you aren't changing sheet size, probably just go with the same size you've got. What is the main problem you want to solve? The deck block just needs to run freely and stand up without fouling. For the clew block, the lighter the better especially in very light air days.

probably just go with the same size you've got.

Thanks. I just wanted to make sure what I buy is gonna do the job. This makes sense.

-Matt

Go with the Harken 2139.

That would be nice, but just a tad outside of my budget.

-Matt

I wasn’t sure if you needed the clew block, or the main blocks.
I have a set of harken ratchet blocks…they look just like the 2139s mentioned above.
You can have them for cheap, they’ve been sitting in my parts box for a few years. I think they came off a Mystere 20 footer I had.
I’m doing a 5000km road trip on Adventure motorcycles, in western Canada Rockies right now. I will be dropping down into the USA in Montana, & shipping from the US is cheaper than Canada.
PM me an email address, I’ll send you some photos of them.
If you decide you don’t like them, send them back & I’ll refund any purchase price.
To be clear, they are NoT the modern 2139s mentioned, they do the same thing but are older style. Ratchet function is guaranteed.
I think they are equivalent to the 75mm blocks mentioned.
You can have them both $75

Edited by Edchris177 on Jul 20, 2024 - 11:10 PM.

PM me an email address, I’ll send you some photos of them.

PM sent - thanks!