2027 Grand Design Momentum G-Class21G

The 21G is the smallest way into a G-Class garage, and it is a genuine toy hauler rather than a trailer with a ramp: a full-sized rear ramp door, a flat garage floor with no wheel wells, rear-ramp loading lights with a back-up function, 2,500-pound tie-downs anchored into the chassis and a 30-gallon fuel station with interior and exterior gauges — all standard across the G-Class travel-trailer roster. At twenty-six feet eleven inches on one slide, it is the only single-slide plan of the seven. Laminated aluminum walls at R-7 sit under a 5-inch radius wood-framed R-40 roof with a double-insulated front cap, and the underbelly is heated and enclosed with suspended tanks.

Grand Design publishes 11,000 pounds of GVWR against 7,280 dry, so the payload is 3,720 pounds — more than the entry Momentum fifth wheel's 3,090, in a trailer half its weight. The dry tongue is 1,056 pounds, which is the number to think hardest about: it is a comfortable half-ton figure at rest, but a toy hauler's tongue weight climbs with everything ahead of the axles, and an 11,000-pound loaded trailer will not stay at 1,056. Weigh it loaded and read your vehicle's door-jamb placard before you commit to a half-ton.

Momentum is Grand Design's toy-hauler family, and it spans four rosters across both tow types. The full-size Momentum fifth wheel is the flagship — a 101-inch wide-body coach on MORryde independent suspension with disc brakes, carrying a 60-gallon dual fuel station. The Momentum G-Class fifth wheel sits below it on MORryde CRE3000 suspension and a Rotoflex pin box with a 30-gallon fuel station, and the G-Class travel trailer puts that same garage behind a bumper pull. The Momentum MAV is the compact end — the lightest and cheapest way into a Momentum garage, and the one roster with no fuel station at all. The 21G on this page is highlighted; each other profiled plan links to its own page. The full MY2027 catalogue runs to 28 floorplans across the four rosters; eight are profiled in depth here and the rest are catalogued on the line hub with their weights.

This floorplan carries its water comfortably. A full 90-gallon fresh tank is roughly 20% of the 3,720-pound cargo capacity, leaving the 21G with a usable gear budget even when you tow full.

The published dry tongue weight of 1,056 pounds is 15% of the 7,280-pound dry weight, which sits inside the 10–15% band usually quoted for stable towing. It is still a dry figure: loading the front pass-through and the fresh tank both push it up.

Nothing above changes the ceiling. Loaded to its 11,000-pound GVWR the 21G is towing 3,720 pounds more than its 7,280-pound dry figure, and that is the number your vehicle has to be rated for — not the brochure weight.

Tank balance is generous here: 90 gallons of fresh against 74 grey and 39 black, so waste capacity keeps pace with supply and the fresh tank is the constraint that ends a dry stay.

Ranked by GVWR, the 21G sits 2 of 8 in the Momentum line: 11,000 pounds against a line that runs from 9,950 to 23,500 pounds. That position is the useful thing to know, because the plans immediately either side of it are the real alternatives.

Either side of it in the same line: Momentum 17MAV is 1,050 pounds lighter at 9,950 lb GVWR; and Momentum 28MAV matches it exactly at 11,000 lb GVWR.

1 other Momentum plan shares this floorplan’s 11,000 lb GVWR, so the ranking above separates plans that tow to the same ceiling. On a shared chassis the figure that actually differs between them is cargo capacity and where the weight sits, not the rating.

Against the 21G: the Outback 340BH is 12 ft longer and sleeps 4 more; the Voyage 3235FK is 8 ft longer and sleeps 1 fewer; the Coachmen Catalina 313RLTS is 1 lb lighter and 9 ft longer and sleeps 2 fewer. 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 travel trailers 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 Momentum floorplans profiled here run 5,542 to 18,114 pounds dry and 23 to 46 feet of exterior length across 8 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 Momentum line hub.

This catalog tracks 18 specification fields per floorplan. Named sources publish 16 of them for the 21G. The rest are not shown, because the alternative is reading a figure across from a sibling floorplan or from what the segment usually does — and a number nobody published is worth less than an admitted gap.

Not published for this floorplan: axle count, tire specification. If you find one of these in a manufacturer document for this plan, it belongs on this page.

The completeness figure at the foot of this page (97%) measures the same thing on the full field set: it is a measurement of how much this floorplan’s manufacturer publishes, not of how much research went into the page.

How every figure here was sourced and checked is set out on the methodology page.