RIO Products Mainstream Trout DT Fly Line
- Fly Line
- 5 lb
- Fly
- Plastic
A sensible, no-frills floating line for anglers still learning to cast, built specifically for that purpose rather than as a scaled-down premium line.
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How it ranks among the 18 fly line we track
4.4★ across 216 Amazon ratings, Bayesian-smoothed toward the category average.
216 Amazon ratings, weighted on a log scale so huge counts don't drown everything.
50+ bought on Amazon last month.
Brand identity, imagery, description and spec coverage.
The ProductDome score is separate from the Amazon rating shown above: it combines the Bayesian-smoothed Amazon rating with evidence volume, tracked demand, and data quality across the 18 fly line we track - how the scorecard works · full fly line data report. Confidence: medium - useful but incomplete evidence.Last refreshed Jul 5, 2026. Data-computed, not a hands-on test. Compiled by the ProductDome Research Team.
Overview
The RIO Mainstream Trout double taper fly line, model 6-20751, is a floating freshwater line built for average and novice fly anglers. Its slightly heavier, shorter head is meant to load rods easily for anglers still developing a cast.
RIO positions the Mainstream series below its premium lines specifically for anglers who do not need a technical taper, trading some finesse for a head that is easier to feel and cast. The short, powerful front taper is aimed at solid presentation and turnover rather than the most delicate dry-fly landing, which is the right tradeoff for someone still building casting feel. Buyers weighing this against RIO's higher-end lines should know it is explicitly the entry point in the lineup, not a lighter version of the same line.
- Double taper (DT) floating design
- Short, powerful front taper for turnover
- MaxFloat high-float tip technology
- SlickCast low-friction coating
Who it's for
Suits new and average fly fishers who want a forgiving, easy-loading floating line for general trout water. Less suited to experienced anglers chasing a technical taper for delicate presentations at distance.
Strengths and trade-offs
Drawn from this product's published specifications.
- Easy-loading head suits developing casters
- MaxFloat tip rides high without added bulk
- SlickCast coating reduces friction through guides
- Double taper design for general trout water
- Not built for technical, delicate presentations
- Shorter head trades some finesse for ease of casting
- Positioned as an entry line, not a premium option
Performance notes
The slightly heavier, shorter head is what makes the rod load sooner in the cast, giving newer anglers more feedback than a lighter technical taper would. RIO's MaxFloat tip coating is designed to float higher than a standard tip without adding diameter, keeping the business end of the line riding on the surface. The SlickCast finish reduces friction through the guides, which affects how far and how quietly the line shoots on longer casts.
Specifications
| Brand | RIO |
|---|---|
| Model | 6-20751 |
| Dimensions & fit | |
| Line Weight | 5 lb |
| Construction & materials | |
| Material Type | Plastic |
| Color | Lime Green |
| Included components | |
| Unit Count | 1 |
| Included Components | One RIO Mainstream Trout Dt5F Lemon Green |
| Warranty & support | |
| Warranty Description | 1 year |
| Other details | |
| Fishing Line Type | Fly |
| Strand Type | Single |
| Item Type Name | Mainstream Trout Dt5F Lemon Green |
Other RIO fly line
How it compares
This product against the closest alternatives we track in fly line.
| Product | Amazon rating | Ratings | ProductDome score |
|---|---|---|---|
| RIO Products Mainstream Trout DT Fly LineThis product | 4.4 / 5 | 216 | 3.9 / 5 |
| SF Full Sinking Fly Fishing Line Weight Forward Taper Fly Line for Freshwater WF4 5 6 7 8…SF | 4.5 / 5 | 666 | 4.3 / 5 |
| Scientific Anglers Mastery MPX Fly Line TaperScientific | 4.6 / 5 | 166 | 4.2 / 5 |
| Piscifun Fly Line BackingPiscifun | 4.7 / 5 | 1,600 | 4.1 / 5 |
| Rio Mainstream TroutRio | 4.6 / 5 | 438 | 4.1 / 5 |
Similar fly line from other brands
Questions about the RIO 6-20751
Common buyer questions answered straight from the product spec data - no fluff, no "it depends".
What skill level is the RIO Mainstream Trout DT line built for?
RIO designs the Mainstream series for average and novice fly fishers rather than technical or advanced casters.
Does the RIO Mainstream 6-20751 float?
Yes, it is a floating freshwater line finished with RIO's MaxFloat tip coating.
Is this a double taper or weight forward line?
It is a double taper (DT) line, as reflected in the model number and product name.