If the truss rod is extremely tight...

[Jim C]

Early 70's Jazz with rosewood block neck
Has some ski jump but more importantly the truss rod is very tight and there is a fair amount of bow
Currently has 45-105 Fender round wounds
With strings loosened the neck does return to flatish shape

Am thinking that the best fix without a lot of professional neck work would be to go to lighter strings like maybe 40 - 100 nickel plated steel on a round core.
Am also thinking that the E string is the most tension and that maybe a 40-95 set might be in order.

Is this a good plan?
Any recomendations for strings with very low tension?

[202dy]

This is not that big of a deal.

The idea is to force the neck into a back bow unstrung and tighten the truss rod. Here's how to do it.

Loosen the truss rod. Place a blocks on the fingerboard at the behind the first and fifteenth frets. Place a strong beam on the blocks. Take a clamp and a shaped caul and place on the back of the neck and the beam at the seventh fret. Tighten the clamp until the neck is in a black bow. Tighten the rod until it is tight. Remove the clamp and blocks. Finish setting up the guitar.

Sometimes it will take a few tries before it holds. Sometimes the neck will remain in a back bow when the strings are brought up to pitch. If it does, simply loosen the nut until proper relief is achieved.

[Jim C]

Thanks, forgot to mention that I have not done the obvious yet (lubricate and install washers under the truss rod nut) but was interested in string tension for this neck non the less.

Will start getting materials together to create this back bow without scarring up the neck

[Benjamin Strange]

Be careful when you do this to watch your frets for lifting. Backbow can sometimes cause the fret tangs to lose their grip on the fret slots, causing them to lift and subsequently causing fret buzz.

For the record, I find that heat pressing a neck is a much better way of doing things than the method above - the wood is more responsive, and it becomes a more permanent fix.

EDIT: Don't try this at home, kids.

[Mrdak]

I've been using 40-100 strings on my jazz with rosewood board for this same reason, and the neck holds the adjustment better and longer with light gauge strings.
Unfortunately they react to humidity changes much faster than a maple board, so keeping her in the case will help a great deal with stability also.