At the turn of the century one of the hottest new technologies was the tubeless tire system. Now, it seems to be all but forgotten. Unlike many components, there are just not that many new developments to be made to keep this performance enhancer in the limelight. In fact, many mountain bikes come equipped with tubeless compatible components and their owners don’t know it. As salespeople, sometimes we even forget to mention it. But using a tubeless tire system can increase the performance and enjoyment of our rides. There are two distinct types of tubeless systems available today.
In order to create a tubeless tire system, an airtight seal was needed in the rim bed. Mavic accomplished this by developing a method of installing the spokes from the hub side of the rim, leaving the inner rim bed completely sealed. The rim bead seat was also redesigned to provide an airtight seal and Universal System Tubeless (UST) was born. The tire companies Hutchinson and Michelin designed special tires that use a stronger bead wire to withstand the increased stress of the airtight bead seal. In addition, the UST tire has a layer of rubber inside the casing to complete the air containment.
Why go tubeless? The benefits of tubeless tires include lower rolling resistance, greater traction and less punctures. Without a tube, the rider can use lower tire pressure with less risk of pinch flats. With lower pressure, the tire contact patch is larger which provides more traction. The rolling resistance is decreased because with the lower tire pressure because the tire deforms and rolls over more objects instead of being deflected.
However, benefits do not come without cost. Upgrading to a UST wheel set with tires will cost several hundred dollars. Weight is always an issue on a bicycle, especially when it comes to wheels. A tubeless wheel set is of comparable weight, but the tubeless tire is a little heavier than its non-tubeless counterpart with tube. Installation can be frustrating if the tire does not inflate right away. Also, air pressure of approximately 60psi is needed to seat the bead completely; not an easy task without a floor pump or compressed air. Finally, the tire is still subject to punctures from sharp objects, and pinch flats can still occur if the tire pressure is too low. Instead of pinching a tube, the tire will have two punctures in it.
A lower cost alternative to UST tubeless is a tubeless conversion kit. While Bontrager manufactures a kit for its own brand, the most popular conversion kit is made by NoTubes.com. The tubeless conversion is made possible by a rim strip and valve combination that seals the rim spoke holes and provides an airtight bead seat. Therefore, any UST tire can then be used. More often though, a standard tube tire is used with a liquid sealant inside.
The benefits of a tubeless conversion kit are many. First, it provides all the performance enhancements of a tubeless tire system at a much lower cost. Second, the wheels are much lighter weight if used with sealant and a tube type tire. Finally, puncture resistance is increased with the sealant and seating the bead is often easier.
Tubeless conversion kits also have own their drawbacks. Installing or removing the sealant can be messy. Latex based sealants are prone to drying out, needing to be “refreshed every couple months or so. Similar to UST tubeless, initial inflation and sealing can sometimes be a challenge. Tire selection is reduced due to manufacturers recommendations.
Replacing tires is often a task that no one wants to do. New tires are not nearly as glamorous as a new shock. But look at the stacks of tires in any race truck and you will see how important tires are to performance. The correct tire and the benefits of tubeless could be just what you need to put a little excitement into your riding. Ten years later, what’s next? Road tubeless.
Tips for Tubeless
* Follow the manufacturers recommendations and instructions.
* Upon initial inflation, lubricate tire beads with soapy water. Use as little pressure as necessary to seat the bead and wear safety glasses.
* When using sealant, immediately after seating the beads, shake the tire horizontally to better distribute the liquid.
* Start with initial pressure 5psi less than with tubes. Decrease slowly until comfortable or you reach 30psi. Inadequate pressure leads to pinch flats and decreased control.
* When performing repairs, unlock as few tire beads as necessary. That means one.
* Inspect tire casings, treads and inflation pressure often
* Tubeless conversion for Cyclocross.