AR-PRO 3.50/4.10-18 Dirt Bike Inner Tubes with TR4 Straight

These AR-PRO 3.50/4.10-18 inner tubes are heavy-duty butyl replacement tubes with TR4 straight valves designed to fit a wide range of 18" off-road motorcycle tires for reliable, airtight performance.

When you need dependable replacement tubes for trail days, practice sessions, or race prep, the AR-PRO 3.50/4.10-18 inner tubes combine a universal fit with durable materials and a straight TR4 valve for easy inflation. Built from premium butyl rubber, they offer resilience against punctures, heat and cold aging, and repeated flexing—helping keep you riding longer between repairs. Each 2-pack contains tubes sized to fit commonly used 18" dirt bike tires, making them a convenient spare to carry or keep in the garage.

How do these tubes match different 18" dirt bike tires?

AR-PRO 3.50/4.10-18 tubes are manufactured to cover a range of tire widths, so one tube can serve multiple tire specs. The nominal sizing accommodates 3.50 to 4.10-inch tire widths and is compatible with sizes commonly listed as 100/90-18, 110/80-18, 110/90-18, and similar 18" designations.

• Compatible sizes: 3.50-18, 4.00-18, 3.50/4.10-18, 100/90-18, 110/80-18, 110/90-18.
• One tube size fits multiple tire width ranges for fewer SKUs needed.
• Designed for standard 18" rim diameters used on many off-road motorcycles.

What makes the TR4 straight valve useful off-road?

The TR4 straight valve provides a robust stem that works with common pump and compressor fittings, and it’s easy to access when the wheel is mounted. Its straight profile reduces the chance of valve stem stress in knobby tires and simplifies adding or releasing air trackside.

• Straight TR4 valve fits most air tools and manual pumps.
• Sturdy base reduces wobble and stem damage during heavy off-road use.
• Accessible for quick inflation, pressure checks and sealant application.

How durable and repairable are these butyl tubes?

Constructed from high-quality butyl rubber, the AR-PRO tubes prioritize airtight integrity, resistance to environmental aging, and puncture tolerance compared with cheaper materials. Small punctures can typically be patched with standard tube repair kits, extending service life and reducing downtime.

• Butyl composition resists air loss and temperature-related degradation.
• Puncture repairable using conventional vulcanizing or patch kits.
• Engineered to flex without cracking under repeated off-road loads.

What are the best practices for installing these inner tubes?

Correct installation reduces pinches, twists, and premature leaks. Slightly inflating the tube before seating it inside the tire prevents folds and keeps the tube centered while the tire bead is worked onto the rim.

• Partially inflate the tube just enough to hold its shape before mounting.
• Avoid sharp metal tools; use plastic tire levers to protect the tube.
• Ensure the tire bead is evenly seated and rotate the wheel to check alignment before full inflation.

Who is this for? The AR-PRO 3.50/4.10-18 TR4 inner tubes are for off-road riders, pit crews, and weekend mechanics who want a reliable spare that fits multiple 18" tire widths. They suit motocross and trail riders who value easy valve access, durable butyl construction, and tubes that can be patched and reused. Keep a two-pack in your toolkit for quick roadside fixes or as replacements during bike maintenance.