Fly Reel Guide: Large Arbor vs Mid-Arbor Explained

If you’ve spent time fly fishing, you’ve probably noticed the terms “large arbor fly reel” and “mid-arbor fly reel.” But what do these terms actually mean, and how do they affect your fishing experience? In this guide, we break down the differences between large and mid-arbor fly reels and help you decide which reel is best for your next fishing trip.

What Is Arbor Size in a Fly Reel?

The arbor is the central spool of your fly reel where your fly line and backing are stored. The size of the arbor affects:

• Line retrieval speed
• Backing capacity
• Line memory

Large arbor fly reels have a bigger spool diameter, while mid-arbor fly reels are slightly smaller—offering a balance between traditional small reels and modern large arbor designs.

Typically, large vs mid-arbor is a debate among saltwater fly anglers, but many freshwater reels are also large arbor designs. They come in handy when a big fish starts running towards your drift boat or raft and you need to pick up the line quickly. Examples include the Sage Arbor XL and Euro Nymphing reels like the Sage ESN. 

Line Retrieval Speed: Large Arbor vs Mid-Arbor

Line retrieval speed is a key consideration when choosing a fly reel:

• Large Arbor Fly Reel: Each turn of the handle retrieves more line, making it ideal for fighting fast fish or quickly picking up slack.
• Mid-Arbor Fly Reel: Retrieval is slightly slower than large arbor but faster than traditional small arbor reels. It offers precise control for delicate presentations or technical nymphing.

Line Memory and Fly Fishing Performance

Line memory is when your fly line retains coils and can cause casting issues. This generally applies to bigger diameter and narrow spools vs large arbor wide spools. A perfect example is the Sage ESN reel. Arbor size plays a role here:

• Large Arbor Fly Reels: Reduce line memory and keep your fly line straighter, resulting in smoother casts.
• Mid-Arbor Fly Reels: Still minimize line memory compared to old-school reels but slightly more than large arbor designs.

Backing Capacity Considerations

Backing is the extra line spooled before your fly line, and arbor size affects how much your reel can hold:

• Large Arbor Fly Reel: Holds less backing for the same reel size, usually fine for most freshwater applications.
• Mid-Arbor Fly Reel: Can hold more backing, useful for big trout, steelhead, or saltwater species that make long runs.

Backing isn’t nearly as important with the majority of freshwater game fish. With a few exceptions—like carp, Chinook salmon, bull trout, or exceptionally large musky- most freshwater species don’t run far enough to ever test your reel’s capacity. For trout, bass, or panfish, the backing serves more as insurance than a necessity, since fights typically stay close and within the fly line.

Drag Performance and Balance

Drag performance is critical when landing strong or fast fish:

• Large Arbor Fly Reel: Provides smooth, consistent drag and balances well with modern fly rods.
• Mid-Arbor Fly Reel: Drag is still reliable, but may fluctuate slightly on long runs. Lighter weight can be better for smaller rods or long fishing sessions.

Large Arbor vs Mid-Arbor: Quick Comparison