ARK Corporation makes the most widely used jockey wheels in the market. The XO series covers three load ratings — 350 kg (≈770 lb), 500 kg (≈1,100 lb), and 750 kg (≈1,650 lb) — but they look nearly identical. Here's what separates them.
Quick Comparison
| XO350 | XO500 | XO750 | |
|---|---|---|---|
| Load rating | 350 kg (≈770 lb) | 500 kg (≈1,100 lb) | 750 kg (≈1,650 lb) |
| Legs | Standard-duty | Heavier-duty | Heaviest-duty |
| Clamps | Standard sizes | Standard sizes | Larger sizes |
| Best for | Mid-size RVs | Large RVs | Boat trailers |
XO350: The Standard RV Jockey Wheel
The XO350 is the most commonly fitted ARK wheel on production rigs. Rated to 350 kg (≈770 lb) static load — enough for a fully-loaded mid-size off-road rig.
Use it for: Black Series HQ12, HQ15, HQ17 (nose weight typically 150–220 kg / ≈330–485 lb loaded). Most rigs with ATM under 3,000 kg (≈6,600 lb).
XO500: For Heavy Rigs and Loaded A-Frames
The XO500 steps up to heavier-duty legs and a 500 kg (≈1,100 lb) rating. The heavier leg and stronger clamp body account for the capacity increase.
Use it for: Black Series HQ19, HQ21 (nose weight can reach 280–320 kg / ≈620–705 lb fully loaded). Any rig where you routinely carry heavy items on the A-frame.
XO750: For Trailers, Not RVs
The XO750 is a commercial/marine unit. For RV use it's overkill — the extra weight serves no purpose.
Our Recommendation by Rig
| Rig | Nose Weight | Recommended |
|---|---|---|
| HQ12/HQ15/HQ17 | 120–240 kg (≈265–530 lb) | XO350 |
| HQ19/HQ21 | 200–310 kg (≈440–685 lb) | XO500 |
If in doubt, size up. The XO500 costs a bit more than the XO350 and lasts years longer when operating near load limits.
Shop the full ARK jockey wheel range at RV Parts Giant.