I just received a pre-owned Brooks Bows 3 pc t/d longbow. I'm hoping someone here could help with where to start the string that came with it even twisted up alot is at 6 inches brace height.

Definatly sounds low.I would think 6 and 3/4 to 7.5 would be in a good range for a 3 piece longbow typically.

It wont hurt to overtwist it in my experience to a point.I have shot strings that had too many twist in them.Or more than I would like but they were functional.

Perhaps its not the original string made for that bow or it stretched alot over time.

I would add more twist and see how it goes.It will shorten quickly when its got too many twists or an undesirable amount of twists.

sounds like you may want to get a string made soon  of appropriate length.

Brooks made some pretty bows!

Thank you for the help, I will twist it a bit more and try it out before dark

My 3 pc LB likes 7-7.5 ish

Thanks for the help... So I got 6.5 and tried again it was much quieter but still some slapping on the wrist then I looked at the other limbs that came with it that is marked 64" versus the set I put on that is marked 62" and only one string so that explains alot. I'll order a new string tonight.
Thanks again

LOL.

Should need a string thats 2 inches shorter than the one you have for your 64 incher.Probably need a 59 inch string or possibly 58 inch.Depending on the bow.Lengths are not always universal on bows.I use anywhere from 55 to 57 inch strings on recurves that are 60 inch recurves.So all 60 inch recurves dont necessarily take the same length string.

you definatly dont want your string to be too short.Longer is better to error on as you can shorten with twist

I would take the string for your 64 inch longbow and take the twist out till its reasonably untwisted and measure it tip to tip and reduce by 2 inches for your 62 inch bow.

Thanks for the help... I got a 59" string twisted it down to a 7 1/4 brace height and bang now she quiet as a whisper, no wrist slap and shooting outstanding.

Good advice given, personally I shot 56" string on my 60" recurve and 57 1/2" on my 60" longbow.