What determines a up lock or down lock reel seat on a fly rod?

An up locking reel seat has the moveable hood to the rear of the back reel foot, and you have to screw the nut up to lock the reel in place. A down locking reel seat has the moveable hood in front of the reel foot and you have to screw the nut down to lock the reel in place.
Norm

With a up locking seat the reel sits further from the butt. With a down locking seat the reel sits closer to the butt.
Typically a fresh water seat is down locking. A saltwater is up locking to facilitate putting the butt in your belly.
herb

I should have said this another way, when you build a fly rod what determines if you use a up lock or down lock reel seat, or is this personal preferance.

so it has nothing to do with balance or preformance

so it has nothing to do with balance or preformance

Jerry

It is personal preference and other considerations. An up locking seat moves the reel forward and does change balance a bit. The grip for an up locking seat is usually inlet to accept the seat's hood which in turn means not all grip styles (half Wells or really skinny cigar or torpedo grips for example) will easily accommodate the reel seat hood inlet. Up locking seats work with fighting butts for heavier rods - 6 weights and above - while down locking seats do not.

Any rod "performance" impact is minimal. Balance point (without defining balance point) is impacted and is another of those highly personal preference items impacting casting feel but not rod action.

My preference favors down locking seats for 2 thru 5 weight rods and up locking seats for 6 weight and greater. However, I have aging 8 weight Winston with no fighting butt and down locking seat that casts like a dream an is a go to rod for black bass. Life's just full of exceptions to general rules.

Thanks Donald this was a great help

I am building a 8'6" 7 weight fiberglass in down locking with fighting butt, it is just an uplocker reversed with an inlet butt. I have even seen small fighting butts glued to flat round down locking seats. Heavier and longer blanks benefit more with a downlocker for balance and many grips that start off skinny near the butt like cigar,Fenwick and Ritz.It comes mainly down to personal preference.I have been wondering lately if a Czech nymph rod would do well with a downlocking reel seat.

One other factor in your choice. If you have tendency to stand your rod up against something while fishing, a downlocking seat can put the reel in the dirt.

Phil has the best reason I think, I vote for the up locking in all cases

William Sidney
AK

I've recently researched the up vs. downlocking approach for my own builds and one thing I came across was "rod" balance vs. "casting" balance. We all know the test where you balance the cork handle on a finger or two to find the balance--but this balance is only practical if you plan to hang the rod on a peg on its handle! Fly casting is not a pendulum whereby the reel and rod length are on either side of a fulcrum (effectively casting by pivoting wrist). Ideal rod balance is an extension of the angler's arm (think body and arm movement, tip traveling straight line). I've tried casting my fly rods with a length of line taped to the reel seat without a reel and must admit, casting is even easier/more accurate (essentially this all that's done in euro-nymphing or tenkara).

With that said, I think you're safe choosing a reel seat solely for the aesthetic or tradition of the design. I tend to go uplocking on most trout rods to keep reel as close to my grip as possible, but use down loacking for tradition's sake, such as on short fly rods or fiberglass fly rods.

Wish I could pull up the source where I read this--maybe Carl McNeil at Epic or from Tom Morgan.

Hope it helps in having to make a not-so-critical decision.

A.