Fly fishing reels are cylinder-shaped devices with spools attached to fishing rods that turn and wind on their axis at a certain speed to handle the special fishing line used with the weightless bait used to catch fish. Here's some more information about fly fishing reels.
Type of Fly Fishing Reels
There are three different types of fly fishing reels: automatic, multiplying and single action. The automatic ones are said not to work as well, but are good for the person new to fly fishing. As the name suggests, this type of reel automatically retrieves the fly line so the angler doesn't need to turn the handle. A button is pressed to retrieve the line. Automatic fly fishing reels tend to be heavier and break easily because of all the parts. Drag setting is poor as well making this type of reel hard to use to catch large fish. Multiplying reels use a lot of different gears to allow the line to be reeled in faster. They also tend to be temperamental with a complicated set of springs and gearing. This gearing allows for faster retrieve which can be handy when catching bigger fish. Single action fly fishing reels is used by most serious anglers. They have few parts so they don't break as easily. They're easy to use because on turn of the handle equals one complete turn of the spool when reeling in fish. Spool changes are straightforward.
There are two types of fly fishing reels: spring-and-pawl and disc-drag. The first is traditional with even tension that allows the line to be reeled in smoothly. They work better for smaller fish since the line tends to loosen when a bigger fish fights. The disc-drag fly reel system has been compared to the brakes of a car. It has a pad inside the unit that's adjusted by the drag of the reel to apply more or less tension as needed to the line. They don't seize up with large fish but the line tension tends to be more uneven than the spring-and-pawl system.
Fly Reel Weight
The fly reel weight should match the fly rod weight. Too light a fly reel and you won't be able to put all of the fly line and backing on it. Too heavy and you'll have too much extra space and this could lead to the line tangling. If the fly reel is too heavy it could also throw off your casts. To make sure you have the right fly reel weight, the rod weight must equal the line weight which must equal the reel weight.
Backing for Fly Fishing Reels
Backing for these types of rods is a monofilament line attached to the spool on one end. The line would go out of the other end of the spool on the reel. It extends the line of the reel which is a good thing when catching a large fish. Fly fishing lines aren't usually longer than 90 feet and this can be used up very quickly when catching a big fish. Buy a quality fly fishing reel to make sure there's enough room for the backing if you choose to use it. Cheaper reals won't have enough room for it.