NATGAI 2 Pack 18x8.50-8, 18x9.50-8 Inner Tubes, Replacement Tire Tube with TR-13 Straight Valve Stem, Fits Lawn Mowers, Yard Tractors, Go Karts, Golf Carts, ATVs, Wheelbarrows, Hand Trucks

What It Is

This is a 2-pack of 18x8.50-8 and 18x9.50-8 inner tubes with TR-13 straight valve stems, designed to replace worn or punctured tubes in lawn mowers, yard tractors, go karts, golf carts, ATVs, wheelbarrows, and hand trucks.

Fitment & Compatibility

Check your tire sidewall for the exact size—must be either 18x8.50-8 or 18x9.50-8. These tubes fit both sizes because the tube stretches to fill the tire cavity. The TR-13 stem is straight (not angled), so verify your wheel rim has clearance for a straight valve. These are aftermarket, not OEM-specific; they work with most brands (e.g., John Deere, Cub Cadet, Toro) as long as tire size matches. Measure your current tube’s width and diameter—do not rely on tire size alone if the tube is oversized or undersized for your rim.

Key Things to Know

• Quality: 4.1 rating from 17 reviews—decent for the price, but some users report valve stem leaks or premature wear. Inspect stem seal during install.
• Installation: Moderate difficulty. You’ll need tire irons and a bead breaker. The tube is flexible but can pinch if not lubricated with soapy water. Inflate to low pressure first, then seat the bead.
• Common gotcha: The TR-13 stem may be too short for deep-dish or offset rims. Measure stem length (typically ~1.5”) and check if it clears the wheel hub or axle.
• Dual-size fit: These tubes are sold as fitting both 18x8.50-8 and 18x9.50-8 tires, but if your tire is on the larger end, the tube may be slightly loose—use a tire liner if needed.

Should You Buy It

If you need a budget-friendly 2-pack for standard lawn mower or small utility tires and can handle basic installation, this is a solid value. Skip it if you need a heavy-duty tube for high-speed ATV or golf cart use, or if your rim requires an angled valve stem—look for a more robust option with a longer stem and higher ply rating.