What They Have in Common
Both are three-accessory push carts: umbrella holder, cup holder, and storage console are included with each. The Nitron's fold is auto-open; the PX4's is a two-step E-Z Latch. They're close in weight — 16.7 lbs for the Nitron, 17.2 for the PX4 — and both list well under $350.
Where They Differ
Folded Size
This is the biggest gap between these two, and it has nothing to do with the carts and everything to do with what the makers publish. The Nitron folds to 19 × 13.5 × 22 inches — 3.3 cubic feet, with 22 inches as the longest single dimension. The PX4? Sun Mountain doesn't publish a folded size for it. That means you can't compare them on trunk fit. If you park in a small car and the rear cargo area is a known quantity, the Nitron lets you measure before you buy. The PX4 doesn't.
That 22-inch longest dimension on the Nitron is worth thinking about. If your trunk is shared with a stroller or a set of clubs in a travel bag, that's the number to check.
Wheels, Brake, and Stability
The PX4 has four wheels with extendable front axles. The Nitron has three. What either cart does on a slope is not something a spec sheet settles.
The Nitron has a handle-mounted parking brake. Sun Mountain's copy describes no brake for the PX4. That's worth knowing if your course has a slope near the green where you set the cart down and walk away. Bag Boy publishes that the Nitron has one; Sun Mountain doesn't say the PX4 does.
Bag Retention and the Auto-Open
Bag Boy's Top-Lok system locks a compatible Bag Boy bag to the cart — a compatible Bag Boy bag, so check yours before counting on it. The PX4 uses adjustable-length bungee cords.
The Nitron's fold is auto-open: a gas piston unfolds it. Bag Boy calls this the Nitro-Piston. The PX4 uses a two-step E-Z Latch System. Both fold differently; Bag Boy publishes theirs as gas-assisted, Sun Mountain describes theirs as two steps.
Warranty
The PX4 splits its coverage: three years on the frame, one year on other parts. The Nitron offers a flat two-year limited warranty. If the frame outlasting the wheels or accessories by two extra years matters to you, that's the PX4's clearest advantage.
Price
The Nitron lists at $319.95. The PX4 lists at $330. That's $10.05 at list. Not a deciding factor on its own.
Who Should Buy Which
Get the Bag Boy Nitron if:
- You need to know the folded dimensions before you commit — the Nitron publishes them, the PX4 doesn't
- Your course has slopes and you rely on a parking brake to hold the cart while you putt
- You carry a compatible Bag Boy bag and want it locked to the cart
- You want a flat two-year warranty with no parts split
Get the Sun Mountain PX4 if:
- You want four wheels and extendable front axles
- You don't carry a compatible Bag Boy bag, so Top-Lok isn't a draw for you
- The three-year frame warranty matters more than the one-year coverage on other parts
- You're fine measuring a cart's folded size in person before buying
The Bottom Line
These are close carts at close prices. The $10.05 gap at list is almost nothing. What isn't close is the information available: the Nitron gives you a folded size, a published brake, and a gas-piston auto-open; the PX4 gives you four wheels and a longer frame warranty. For most buyers who walk and need to know a cart fits their trunk before it arrives, the Nitron is the easier call.
Get the Bag Boy Nitron.