When to reef?

[RichH]

Originally Posted by lawsonmitchell

I got svHyLyte. When I say trimming the traveler, I mean windward or leeward as needed. For flattening... I use the cunningham and the outhaul. But the vang? Wouldn't increasing my vang tension cause my leech to cup/curl? In heavier winds I always thought I was trying to increase the twist in the leech to spill off the stronger winds up top. No?

The vang will prevent the boom from rising ... which when rising will increase the amount of overall draft and 'power-up' the sail, especially when the mainsheet is 'eased' or released.
Increasing twist to depower in high wind conditions may result in unforseen and unexpected 'power-ups', better to flatten and reduce twist as much as possible. Besides the higher the windspeed the less 'gradient wind' between the masthead and the water.
If you over-twist the head to depower, the resultant flogging at the head may cause broken stitching or 'worse' ... the higher the windspeed the faster the destruction from flogging; better to have a radically flattened sail and then 'blade-out' (via traveller, etc.) the sail when needed when overpowered.