Anglers who use spinning or bait casting reels give little thought to the mechanical processes taking place as they spin the handle to retrieve a lure or fight a fish. That's good, because a reel that attracts attention at such times usually spells trouble.

Whether we take pause to notice or not, our seemingly simple reels perform some rather complex tasks as they wind line onto the spool. Turning the handle sets gears in motion and gets the spool moving — a baitcaster's spool revolves while a spinning reel's moves up and down.

Wrap Session
Manufacturers study and constantly strive to improve line-winding performance because the manner in which line goes on the reel helps determine how it comes off.
 
"Improving casting distance has always been a priority on Daiwa's engineering agenda," explains Toru Takahashi, sales manager for the company. "Years ago, we recognized that line-lay patterns affect the way line leaves the spool, and we developed a long-stroke spool design to maximize casting distance in our   spinning reels."
 
A spinning reel's rotor remains "stationary" as it turns; that is, it revolves around the same point while line distribution becomes a function of the spool's movement. The spool's stroke — how far and how fast it moves up and down    during the retrieve — defines line lay. A slow or short stroke can cause line to bunch up with overlapping wraps. Longer, faster spool strokes arrange line in an X pattern.
 
Criss-crossing on the spool stops line from digging into itself when an angler applies drag pressure, and it helps prevent coils of line from forming and looping off the reel during casts. A wider wrap pattern helps line flow off the spool more smoothly and easily, resulting in better casting performance. All these factors obviously concern anglers who use monofilament, and they become even more critical for users of Spectra because superbraid's limpness and thin diameter can cause line-management headaches if not laid down properly on the reel.
 
Daiwa tweaked its spinning-reel   gearing and developed the Advanced Locomotive Levelwind system, available on certain models such as the Sweepfire-B. Have you ever noticed that some spinners wrap line thicker at the top and bottom of a spool, creating a dip in the middle? Advanced Locomotive Levelwind cross-wraps line while distributing it evenly on the spool, with no bunching or dips. According to the company, benefits of this system include reduced casting friction, fewer tangles and more consistent drag performance.
 
"Traditional spinning reels move the spool with a worm shaft, a long, small-diameter shaft with a pawl riding on it. Think of the stress it takes when you crank on a fish," says John Bretza, national sales manager for Okuma. "Another common system uses a round main gear coupled with a slider system. This one can cause the spool to jump at the top and bottom of the stroke."
 
Okuma addresses these and other issues with its patented Elliptical Oscillation System (EOS). Introduced in 2005, EOS is based on an oval-shaped, offset oscillation gear that works similarly to a two-speed transmission. The gear's unique shape and action, reminiscent of the drive on an old-time locomotive, moves the spool a bit faster at each end of the stroke. "Other reels may cause the spool to pause or jump at these transition points, which bunches up line," Bretza says. "EOS provides even line lay along the entire spool. That's especially important with braided line because uniform, precise line lay helps castability."
 
Adding that EOS relies on a large  oscillation gear that equals the size of many reels' main gears, he says. "Worm-shaft oscillation systems give good line lay but the relatively small components can result in unstable gear contact. EOS not only lays line smoothly, but is one of the strongest systems in the industry."

Twist Reduction
Use a spinning reel long enough and you'll likely encounter problems with line twist, no matter how well the line-laying system works. "It's inherent to the beast. The way spinners work ends up twisting line," says Bill Liston, Daiwa's manager of East Coast operations. "We noticed that one cause of twist involves the way line travels over the roller [the part on a spinning reel's bail that directs line onto the spool]. So about 10 years ago, we invented Twistbuster to solve the problem."
 
Instead of a standard cupped line roller like that found on other spinning reels, Daiwa's Twistbuster uses one with a unique shape that prevents line from rolling across it and twisting. "It's a simple mechanism. The line roller has one or two bearings, depending on the model," Liston says.