Product Description
This 18-inch rear inner tube is designed for mid-to-wide profile motorcycle rims. Manufactured from thick butyl rubber, it provides consistent air retention, structural flexibility, and puncture resistance during highway, street, or trail use.
This rear inner tube matches an 18-inch wheel running a metric 120/80-18 tire size. It serves as a direct cross-fitment for traditional imperial inch sizes, including 3.50-18 and 4.10-18. It includes a threaded, straight metal TR4 valve stem equipped with a lock ring and valve cap, which anchors the stem to the rim hole to prevent movement or shearing under acceleration and braking forces.
This sizing is common on dual-sport motorcycles, intermediate off-road dirt bikes, vintage standard motorcycles, and custom café racer builds requiring a tubed, 18" rear tire setup.
Fitment & Size Compatibility
This 18" rear tube spans modern metric measurements and traditional standard-inch designations.
Size Cross-Reference:
- Metric: 120/80-18, 110/90-18, 120/90-18
- Imperial (Inch): 3.50-18, 4.10-18, 4.60-18, 3.50/4.10x18
Common Vehicle Fitments:
- Dual-Sport & Enduro Motorcycles: Fits 18-inch rear spoked wheels on common dual-sport and trail models running mid-sized metric or imperial rear knobby/dual-purpose tires.
- Vintage & Classic Standard Motorcycles: Fits older-generation standard and metric cruiser motorcycles from Honda, Yamaha, Kawasaki, and Suzuki utilizing an 18-inch spoked rear rim.
- Custom Café Racers & Scramblers: Suitable for retro builds, custom scramblers, and laced wire wheels requiring a classic 18" rear profile.
Key Features & Bullet Points
- Optimized Rear Profile: Sized specifically for 18-inch rear rims to ensure uniform wall expansion and prevent over-stretching when inflated to operational pressure.
- Butyl Rubber Material: Made from butyl rubber, which provides higher resistance to natural air loss, temperature changes, and structural wear than standard natural rubber.
- Threaded TR4 Valve Stem: Features a straight metal TR4 valve stem with a locking nut to hold the stem securely in place against the rim, reducing the risk of flats from valve rotation under heavy acceleration or braking.
- Size Versatility: Crosses over smoothly between modern metric 120/80-18 tire sizes and classic imperial 3.50-18 or 4.10-18 configurations.
- Thick-Walled Construction: Built with an even thickness throughout the tube body to eliminate thin weak spots and help protect against pinch flats during tire lever installation.
