The tube vs. tubeless debate is common in mountain biking circles. While both systems are reliable and have their own sets of advantages, it may really come down to a rider's preferences and peace of mind. Many riders are satisfied with the option of running either system. Experimenting with the two systems is a sure way to find what works best for you.
Tube Tire Basics
This well-known system is based on having a separate inner tube within the tire itself that inflates with air and dictates the riding performance characteristics of the tire. The tubes are easy to repair in the field, can be carried in a tool kit and are inexpensive to replace. Different tubes are available for different size tires. Tube tires are lightweight, but when coupled with tubes, they become heavier.
Tube Tire Cons
Sharp objects can easily puncture these tubes, or when running lower tire pressure they can "pinch flat," a kind of snake-bite rupture caused by air pressure building up in one area of the tube that is common in off-road bicycling. Repairing a ruptured tube is relatively easy but takes practice and skill to be quick and efficient. A patch kit/spare tube and some basic mechanical skill are necessary for these repairs on the trail.
Universal System Tubeless
UST tubeless tires require no inner tube but do require a special rim that has a lip for the bead of the tire to seat itself in, allowing a proper seal. These rims are compatible with the use of inner tubes, as are tubeless tires, so the rider has the option of either system. Many companies offer versions of the same tire in tube and UST. A valve stem is necessary for the tubeless rim, and many riders choose to add a seam sealant of some kind to avoid air loss and protect against punctures.
Tubeless Tire Advantages
Tubeless tires are somewhat more durable. They are slightly heavier than normal tires, but lighter overall when you consider no need for a tube. Many manufacturers, like IRC, provide an internal liner in their UST tires that prevents leaking or inhibits damage to the casing. According to IRC, applying a thin rubber coating to the inner wall of the tires stops leaking and allows it to be repaired easier in the field.
Less Air Equals Better Traction
In both systems, decreasing air pressure in the tire increases the surface area of the tread in contact with the ground. This results in a better grip, or traction of the tire. Riders can run up to 15 percent less air pressure in tubeless tires, providing terrific traction in the most demanding conditions.
Seam Seal and a Patch Kit
Both types of tires can be repaired with specialty patch kits. As stated, many tubeless users add a sealant to the tire before mounting to the rim, although this may void certain tire manufacturers' warranties. Tubeless tires may also be difficult to install and remove due to the stiff bead designed to grip the lip on the rim.