A quick newbee question…
How long should the backing be in you fly reel?
We fish the streams & lakes of the Sierria’s
Thanks
good question
you want the enough backing that the fly line fills the spool to about 1/8 inch from the outside edge of the spool (the spool not the reel) The size of the reel and the weight of the line dictates how much backing you will need.
just spool the fly line on first then the backing to the level mentioned above. then unspool all of the backing and fly line and reinstall it correctly.
you can keep backing on for about 3-5 years as long as it doesnt mold or get mildew
how big are the fish?
Do they take out the whole flyline?
i dont have any backing on my 5 wt trout rod—200 yds on my 12 wt tarpon reel and 300 yds on my 10 wt reel i use for albies
Consider…
Are the fish likely to run deeply into backing…
Most folks advocate filling to proper level to optimize rate of retrieval when reeling in…whether you need the backing or not
IMO Norm’s way is the way to go…
Remember when you are filling the spool under controlled conditions there is a tendency to wind on tightly and neatly…not likely to happen out fishing so the line may bind …e.i. too full…been there done that but no more…
Also I feel I have less memory problem when I make an effort to spool the line under minimal tension…talking about trout fishing
The most backing I have ever had a trout take is about 50 yards by a 27" 'bow on Lake Crowley. Most trout size reels will hold 50 to 100 yards of 20lb dacron or more with a double taper line. If you load line and backing as described above you should have plenty of backing.
As for replacing every 3-5 years. I have reels that have had the same dacron backing on them for 15 years and the backing is still fine, including my saltwater reels, several of which see 35-40 days on the water a year. I do test the backing once a year by peeling some off the reel then testing it for weakness.
Though common practice is to use 20lb dacron for trout and panfish setups, I often use 30lb dacron. The reel will hold less, but still more than enough in most cases. The local fly shops charge by the yard the same cost for either size.
I see backing maybe once a year. I saw backing maybe once a year when I fished for steelhead, too. So, if I didn’t HAVE any backing, I might lose one fish a year (admittedly probably a real nice fish).
I still have backing on all my reels, more as a spool filler and last-ditch insurance than as something I think I actually NEED.
The bigger the water, the bigger the fish, the more likely you will see it come off your reel while you are fishing. Small water, small fish, nah.
for trout no less then 50 yards
Ray,
I’m curious since I just spooled a small reel for trout with no backing…not my usual practice…
What size rod are you using and what size trout are you targeting?
I’m surprised you are saying 50 yds is a minimum.
The instruction that came with the reel will generally tell you how much backing to use. Check the manufacturers website as well for this information.
On small reels, think of it more as ‘filler’ rather than ‘backing’. It might be seldom pulled off by a fish. 
The amount of backing is dictated by the type of reel you have, the size of line you are installing and the size of fish you are fishing.
The older style reel will usually take more backing than many of the large arbor reels. You want as much backing on the older style reels as possible, like JC and others have said, to use it as reel filler. That will help but not eliminate tight line coil memory.
Some of the earlier large arbor reels do not allow for much backing. A solution to that problem was to use Gel-Spun as backing. That gave the reel a whole lot more backing. If the target fish is a salmon or other larger fish, you need as much backing as possible.
As stated, trout reels usually only use backing as filler. I have had two large brown trout that have taken me well into my backing and once while fishing for smallmouth bass, a twelve pound Carp grabbed me streamer and took out all of my fly line and half of my backing before I could get it stopped. So, you do need backing for those rare big ones, but for trout the use of 20 pound Dacron is all that is needed. For saltwater, the 30 pound Dacron or the heavier Gel-Spun is needed.
Now, fill the reel and get fishing.
Larry 
—sagefisher—
Since most of the time I am using backing as “filler”…I use Dacron bait casting line…you get a lot more for fewer $$$$…
I do 90% of my trout fishing with a 7’ 4wt bamboo rod. I usually only get into my backing once or twice a season. If you use no backing and tie the line tight to your spool the only thing that will happen is when you get a big fish that runs all you line you will break your tippet and lose the fish. The last thing I want to do is lose the biggest fish of the season. Most of the brown trout here over 22" (I may only see 1 or 2 a season)will take you into your backing. When I get to the Delaware many of the wild browns over 18 will take backing. Not only that 50 yards of backing take up very little space on your spool, where any line there will be tightly coiled and likely to retain memory.
dlshunter -
First of all, welcome to the FAOL Bulletin Board, and greetings from SE Idaho.
It should be obvious to you already that you’ve joined a downright friendly and helpful group of people. Can’t really add much to what others have already said - will just echo the lack of need for backing for most trout fishing, except as a reel filler.
Over the past year, the only trout ( out of well over two thousand ) that got close to my backing was a mid to upper 20 inches brown on the Henry’s Fork. I had the choice to let him run downstream to water where I couldn’t follow him or try to hold him on 2x 10# tippet. I decided to try holding him - he broke it off. I have a great memory of a ten second relationship with that big brown; I doubt that landing him would have made it any more special. Only a few of the many trout over 20", up to 23", that I caught in the past year even made it to the reel, let alone the backing.
Usually, someone greeting a new BB member will say something like “the new guy brings the donuts,” but it won’t be me.
John
John,
Jelly filled or chocolate old-fashioned for me:rolleyes:
Larry —sagefisher—
dlshunter 
Junior Member
Join Date: Aug 2008
Posts: 2
Backing…How much is enough?
A quick newbee question…
How long should the backing be in you fly reel?
We fish the streams & lakes of the Sierria’s
Thanks
the question he asked was how long should be on the reel not how much. I said 3-5 years and it depends on how you take care of your equipment, and from what i have seen in the shop many people do not, the backing molds and has the mildew smell .
well, for those of us who use silk fly lines… the ammount of backing is gona be different especially if ya use antique fishing gear as i do…
According to my records, it is John’s turn to bring the donuts. Or at least buy breakfast in Lowell.
After much searching of the memory, I determined that the only backing I have seen in the two years I have been here in Colorado was on a carp I caught on the Gunnison. Er, I mean, um, er, a bigscale trout. Yeah, that’s it.
Bear in mind I won’t chase a fish downstream just so I can land it. Unless maybe it was the fish of a lifetime. And I haven’t seen that one yet. If it is going over the lip of the pool and I need to chase after it over rocks and logs and such, I just point the rod at it, break it off, and catch another one. I did that on a steelhead once, and the guy across the river from me yelled “what the h*** did you do that for?” I replied “It’s just a fish. I can always catch another” and his eyes bugged out. Turns out he had never caught one.