The Ideal Backing Capacity for a 5/6 Fly Reel
A 5/6 fly reel typically requires 100-150 yards of backing when paired with a weight-forward (WF) floating line. The exact amount depends on the reel's arbor size, line weight, and target species. Larger arbor reels need less backing (closer to 100 yards), while standard arbor reels may require up to 150 yards for strong-running fish.
Key Factors Affecting Backing Capacity
- Reel Arbor Size: Large arbor reels retrieve line faster and hold less backing. Standard arbor reels need more.
- Fly Line Type: WF lines (most common) require less backing than double-taper (DT) or sinking lines.
- Target Species: Trout or panfish need minimal backing (100 yards); salmon or steelhead demand 150+ yards.
- Line Weight: A 5-weight line is thinner than a 6-weight, allowing slightly more backing.
Recommended Backing Amounts by Scenario
| Scenario | Backing Capacity (Yards) | Reel Arbor Type | Best For |
|---|---|---|---|
| Lightweight trout/panfish | 100-120 | Large arbor | Small streams, dry flies |
| All-around trout/bass | 120-140 | Mid arbor | Rivers, nymphing, streamers |
| Steelhead/salmon | 150-200 | Standard arbor | Big water, strong runs |
How to Calculate Exact Backing Needed
- Check reel specs: Manufacturer listings often include "backing capacity" (e.g., "WF6F + 120yds 20lb").
- Measure arbor diameter: Large arbor (≥3.5") = subtract 20-30 yards from standard recommendations.
- Test-fit: Spool the fly line first, then add backing until the reel is ⅛" from the rim.
- Line thickness matters: Gel-spun backing (e.g., 20lb) is thinner than braided-allows more yards.
Common Mistakes to Avoid
- Overfilling the spool: Too much backing reduces line retrieval speed and causes tangles.
- Underestimating fish runs: Steelhead or saltwater species can strip 100+ yards in seconds.
- Ignoring line taper: DT lines require ~10% more backing than WF lines of the same weight.
- Using weak backing: For large fish, opt for 20-30lb test even if the tippet is lighter.
Backing Material Comparison
| Material | Diameter (20lb Test) | Yards per Spool (100g) | Pros | Cons |
|---|---|---|---|---|
| Gel-spun (e.g., Dacron) | 0.012" | ~300yds | Thin, high capacity, durable | Slicks under tension, harder to knot |
| Braided nylon | 0.018" | ~200yds | Easy to handle, affordable | Bulkier, absorbs water |
| Fused multifilament | 0.015" | ~250yds | Smooth, abrasion-resistant | More expensive |
Step-by-Step Spooling Guide
- Attach backing to the reel arbor using an arbor knot.
- Wind backing onto the spool under moderate tension (use a helper or pencil through the spool).
- Tie backing to the fly line with a nail knot or loop-to-loop connection.
- Spool the fly line, ensuring it sits flush against the backing (no gaps).
- Leave ⅛" of space to prevent line overflow when casting.