The Quick Verdict
Get the Sun Mountain PX4. It lists at $330 — $29.95 less than the Nitron Swivel — weighs 1.3 lbs less, comes with two umbrella holders and a three-year frame warranty. The Nitron Swivel is worth considering if you want a cart that opens in one step with the Nitro-Piston system and you care about a brake that locks both rear wheels simultaneously; Sun Mountain's copy doesn't describe any brake for the PX4. Check price at TGW →
What They Have in Common
Both are push carts with a storage console and a cup holder. Bag retention is Top-Lok on the Nitron Swivel and adjustable-length bungee cords on the PX4.
Where They Differ
Wheels
The PX4 runs four wheels with extendable front axles. The Nitron Swivel runs three, with a 360° swivel front wheel that locks. A fourth wheel widens the base; whether that matters on your course is a judgment call. Sun Mountain doesn't say whether the PX4's front wheels swivel.
Braking
The Nitron Swivel has a dual rear brake that locks both back wheels at once. The PX4's product copy doesn't describe any brake at all. That's not the same as the PX4 having no brake, but if your course has slopes it's something to confirm before you buy.
What Comes in the Box
The PX4 ships with dual umbrella holders, a drink holder, a mesh basket, and a valuables pouch. The Nitron Swivel includes a detachable umbrella holder, an underbar accessory bag, a cup holder and a deep storage console. The PX4 gives you two umbrella holders to the Nitron Swivel's one, plus the mesh basket and valuables pouch.
Folded Size
The Nitron Swivel folds to 18.7 × 13 × 22 inches. That 22-inch longest dimension is the one to measure against your trunk height. Sun Mountain doesn't publish folded dimensions for the PX4, so there's no comparison to make there — just check whether 22 inches clears your hatch before buying the Nitron.
Fold Mechanism
The Nitron Swivel opens in one step via what Bag Boy calls the Nitro-Piston. The PX4 uses the E-Z Latch system, which takes two steps. Use the maker's terms; that's all either of us knows about how they feel in practice.
Warranty
Sun Mountain covers the PX4's frame for three years, other parts for one. Bag Boy covers the Nitron Swivel with a two-year limited warranty. The frame warranty difference is real over a cart's lifespan.
Who Should Buy Which
Get the Sun Mountain PX4 if:
- You want two umbrella holders on the cart rather than one
- You want the longer frame warranty and can accept that the folded dimensions aren't published
- The $29.95 list-price savings matters to you
Get the Bag Boy Nitron Swivel if:
- Your course has hills and you want a brake that's stated to lock both rear wheels
- You need to know the folded size before buying — the Nitron gives you 18.7 × 13 × 22 inches to measure against
- A one-step auto-open matters to your routine
The Bottom Line
The PX4 lists for less, weighs less, and comes stocked with more accessories — two umbrella holders to the Nitron Swivel's one, plus a mesh basket and a valuables pouch. Sun Mountain's three-year frame warranty is the longer frame coverage, though its other parts get one year to Bag Boy's two. The Nitron Swivel's case rests on two specific things: a dual rear brake that Sun Mountain's copy doesn't match, and published folded dimensions if trunk fit is something you need to confirm before buying.