01 What makes it unique
The 344M is where the flagship Momentum fifth wheel starts. It is the shortest and lightest of the ten, on three slides at just under forty feet, and it carries the full Momentum build: a 101-inch wide-body Super Chassis with drop-frame storage, a five-side aluminum cage, MORryde Independent Suspension 2.0 with disc brakes, six-point hydraulic leveling and 17.5-inch H-rated aluminum wheels. Inside the garage are an R-40 ceiling, keyed-alike ramp-door latches and an LED TV; up front, a twenty-cubic-foot refrigerator, a 30,000-BTU air conditioner, a 35,000-BTU furnace and a 60x80 queen with a king option.
Its numbers deserve a careful read. Grand Design publishes a 19,000-pound GVWR against a 15,910-pound dry weight, so the payload is 3,090 pounds — the smallest of any Momentum fifth wheel, and the reason this plan needs the most honest arithmetic in the line. The 60-gallon dual fuel station alone accounts for roughly 360 pounds of that at about six pounds a gallon, and 140 gallons of fresh water would be another 1,160 or so if you travelled full. What is left is the actual toy budget. The 3,500-pound dry pin is already a serious number for a three-quarter-ton, and it climbs with everything you put behind the axles. This is a one-ton coach in practice, and the payload math is the argument for it.
02 Full specifications
Dimensions
- Exterior length
- 39 ft 11 in
- Exterior width
- 8 ft 5 in
- Width, slides out
- 12 ft 10 in
- Exterior height
- 13 ft 6 in
- Chassis
- 101″ wide body · 5-side aluminum cage
- Garage / flex length
- 11 ft
Weights
- Dry / unit base weight (UVW)
- 15,910 lbs
- GVWR (max loaded)
- 19,000 lbs
- Net cargo / payload
- 3,090 lbs
- Dry pin weight
- 3,500 lbs
Capacities
- Fresh water
- 140 gal
- Grey water
- 104 gal
- Black water
- 52 gal
- LP gas
- 60 lbs · 2 tanks
- Refrigerator
- 20 cu. ft.
Construction
- Chassis
- 101″ Wide Body Super Chassis w/ drop-frame storage
- Body
- 5-side aluminum cage · 101″ wide body
- Sidewalls
- High-gloss gel coat · frameless tinted windows
- Roof
- Worry-Free composite w/ lifetime warranty · walk-on
- Underbelly
- Fully enclosed and heated underbelly and storage area
Running gear
- Hitch
- Fifth-wheel (in-bed) · MORryde® pin box
- Suspension
- MORryde® Independent Suspension 2.0 w/ disc brakes
- Leveling
- 6-point hydraulic
- Tires
- Heavy-duty H-rated · 17.5″ H-rated aluminum wheels
- Spare
- 17.5″ undermount
Garage
- Garage / flex length
- 11 ft
- Garage insulation
- R-40
- Ramp
- Ramp door w/ Keyed Alike™ latches
- Tie-downs
- 2,500 lb rated flush-mount tie-downs
- Fuel station
- 60 gal · dual tank
Galley & systems
- Refrigerator
- 20 cu. ft. 12-volt
- Air conditioning
- 30,000 BTU
- Furnace
- 35,000 BTU
- Water heater
- Tankless
- Solar
- 330W roof-mounted panel · 50 AMP controller w/ Bluetooth · inverter prep · 2 USB dock ports
- Shower
- 30 x 48″
Sleeping & layout
- Sleeps
- 6
- Slides
- 3
- Awnings
- 2 · 18 ft + 10 ft
- Hitch type
- Fifth-wheel (in-bed)
- Primary bed
- 60 X 80 Queen Bed (King Opt.)
03 The Momentum floorplan family
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 344M 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.
| Floorplan | Roster | Type | Length | Garage | Sleeps | Notable |
|---|---|---|---|---|---|---|
| 344M | Momentum | 5W | 39′ 11″ | 11 ft | 6 | Entry Momentum — lowest GVWR of the ten, tightest payload |
| 392M | Momentum | 5W | 45′ 11″ | 17 ft | 9 | Sleeps nine, longest fifth-wheel garage in the family |
| 320G | Momentum G-Class | 5W | 36′ 3″ | 11 ft | 6 | Entry G-Class fifth wheel — lowest GVWR of the six |
| 394G | Momentum G-Class | 5W | 44′ 11″ | 15 ft* | 7 | Top G-Class GVWR, biggest G-Class payload, triple awning |
| 21G | Momentum G-Class | TT | 26′ 11″ | 14 ft* | 6 | Entry G-Class trailer — only single-slide, lowest GVWR |
| 30G | Momentum G-Class | TT | 34′ 10″ | 20 ft 7 in | 7 | Longest garage in the whole Momentum family |
| 17MAV | Momentum MAV | TT | 22′ 11″ | 11 ft 6 in | 2 | Lightest and cheapest Momentum built |
| 28MAV | Momentum MAV | TT | 33′ 11″ | 10 ft 4 in | 6 | Top of the MAV range — the only MAV with a slide-out |
The full-size Momentum is Grand Design's luxury fifth-wheel toy hauler and the top of the family — a 101-inch wide-body coach on MORryde independent suspension with disc brakes, a 60-gallon dual fuel station and a 20-cubic-foot refrigerator. Pin weights here are factory dry figures and a toy hauler's real loaded pin climbs hard once the garage is full — weigh the loaded coach against your truck's payload and rear-axle rating. The other Momentum fifth-wheel floorplans are catalogued on the line hub.
04 What owners & reviewers report
Tightest payload in the Momentum fifth-wheel roster
3,090 pounds against a 19,000-pound GVWR — every other Momentum fifth wheel gives you more. Fuel and fresh water can claim nearly half of it before a single toy is loaded.
Entry price, full build
The lowest GVWR of the ten does not mean a lesser coach — the wide-body chassis, MORryde independent suspension with disc brakes and the 20-cubic-foot refrigerator are the same as the flagship plans.
Sixty-gallon dual fuel station
The full-size Momentum roster is the only one carrying a 60-gallon station; the G-Class runs 30 and the MAV carries none. Grand Design describes it as an enclosed dual fuel tank.
Weigh it loaded, then weigh your truck
A 3,500-pound dry pin on a toy hauler is a starting figure, not a working one. Confirm the loaded pin against your truck's payload and rear-axle rating before you buy.
05 How it compares
The other luxury fifth-wheel toy-hauler entry — a bigger garage and a higher-end interior, at a higher price and a longer body.
Heartland's premium toy hauler, profiled here. Cyclone publishes cargo capacity directly instead of leaving it to arithmetic, and it does not publish a garage length at all.
A bigger garage and nearly twice the payload for roughly forty thousand dollars less — on CRE3000 suspension rather than the independent 2.0, and a 15-cubic-foot fridge rather than 20.