2026 Forest River Riverstone39RKFB

The 39RKFB is where Riverstone starts, and the plan that opens Forest River’s flagship luxury fifth wheel to the broadest range of trucks. At about 16,511 pounds dry it is both the lightest and the shortest coach in the line, and the only Riverstone rated below the line’s 24,000-pound chassis ceiling — its published GVWR is 18,975. The layout is built around the kitchen: a residential rear galley with a stainless dual-bowl sink, a Fisher & Paykel dishwasher, the standard 18-cubic-foot French-door refrigerator and a 30-inch convection microwave, with a bath-and-a-half for guests, a front master suite with a king bed and a dual-sink full bath, and a standard desk in the living room.

Its numbers make it the easiest Riverstone to tow. Forest River lists a published 18,975-pound GVWR against the 16,511-pound dry weight, which leaves a 2,464-pound payload and a 2,975-pound dry pin, on tandem 8,000-pound axles. The full Riverstone build carries through: a 102-inch-wide fully-welded frame, 3-inch hung-glass walls under a high-gloss gel coat, an automatic six-point hydraulic level-up system, two 15,000-BTU heat-pump air conditioners, a Truma AquaGo tankless water heater, a Splendide stackable washer and dryer, 200-watt solar with a 2,000-watt inverter and a 65-inch living-room Samsung television.

At a starting MSRP around $200,000 it is the most accessible Riverstone, and dealers discount it heavily — US street prices well under the placard (often in the $140,000s) are common. For a couple who wants Forest River’s top luxury build and a residential rear-kitchen layout without the length, weight or pin of the big plans, the 39RKFB is the line’s natural entry.

Riverstone is Forest River's top-luxury full-profile fifth wheel — a step above Cedar Creek and a cross-shop against the upper trims of Keystone's Montana and Grand Design's Solitude. The 2026 fifth-wheel line runs to seven floorplans, and all seven are profiled here in full. The 39RKFB on this page is highlighted; each other plan links to its own page.

This floorplan carries its water comfortably. A full 79-gallon fresh tank is roughly 27% of the 2,464-pound cargo capacity, leaving the 39RKFB with a usable gear budget even when you tow full.

The published dry pin weight of 2,975 pounds is 18% of this floorplan’s 16,511-pound dry weight. Fifth-wheel pin weight rides in the bed of the truck, so it comes off payload rather than off tow rating — and it rises with the trailer as you load it, not in proportion to what you put over the axles.

Nothing above changes the ceiling. Loaded to its 18,975-pound GVWR the 39RKFB is towing 2,464 pounds more than its 16,511-pound dry figure, and that is the number your vehicle has to be rated for — not the brochure weight.

Tank balance is generous here: 79 gallons of fresh against 80 grey and 80 black, so waste capacity keeps pace with supply and the fresh tank is the constraint that ends a dry stay.

Of the 7 Riverstone floorplans profiled here, the 39RKFB is the lightest by GVWR at 18,975 pounds — the entry point to the line and the one most likely to suit a vehicle already at its limit.

Either side of it in the same line: Riverstone 442MC is 4,870 pounds heavier at 23,845 lb GVWR.

Against the 39RKFB: the Seismic 3512 is 20 lb heavier and sleeps 3 more; the Influence 3804DS is 25 lb heavier and sleeps 2 more; the Momentum 344M is 25 lb heavier and 2 ft shorter and sleeps 2 more. Those are differences in the published numbers only — what they cost, how they are built and how they live are separate questions each of those pages answers on its own terms.

Those are the nearest fifth wheels from other lines by weight — one per line, picked by proximity on that figure and nothing else. They are listed so the same tow vehicle can be checked against real alternatives, not because they are equivalent inside; layout, build and price diverge sharply across that group.

For scale, the Riverstone floorplans profiled here run 16,511 to 19,271 pounds dry and 42 to 45 feet of exterior length across 7 plans. Where a floorplan falls in that spread usually says more about which vehicle can tow it, and which site it fits, than the layout name does.

Every profiled floorplan in this line, with the full weight table, is on the Riverstone line hub.

Named sources publish 18 of the 18 specification fields this catalogue tracks for the 39RKFB (98% complete on the full field set).

Not published for this floorplan: tire size (a tire description is published, a size is not). Those rows are left blank rather than copied from a sibling floorplan.

Sourcing rules: methodology.