With that said, his write up on our Velotape will come soon but it dawned on me in the meantime: why attempt to write some thing that experts and trusted testers have already said. Who else to turn to than the 29er guru himself, Guitar Ted. I was able to find over at TwentyNineInches.com a series of posts that he made last year concerning tubeless and 'What you need to know'. Enjoy.
Going Tubeless: What You Need To Know- Why Tubeless?
July 6th, 2009 by Guitar Ted
The tubeless tire discussion really can not begin until we cover the “why” of the tubeless tire choice for cycling. While it may seem obvious to some, this may enlighten a few first timers and there may be a few surprises along the way.
First of all, the cyclists worst enemy is a flat tire. Nothing ruins a rides flow like a flat tire. Tubeless tires can puncture, rip, and leak, of course- so does a tubeless tire help in regards to the flat tire problem? Is it worth setting up your tires tubeless for this reason?
The short answer? Yes! Tubeless tires, while vulnerable to flatting, are far less likely to flat, and if you use sealant in them, they are even less likely to lose all the air in your tires. Here is why: A tube in a conventional tire is not part of the tire casing, obviously. Because of this, the tire casing can pinch the tube between it and your rim edge, or “bead”. This can happen when you strike an object hard enough that the force applied overcomes the pressure in the tube to withstand that force, allowing the tire carcass to pinch the tube against the rim. This is commonly referred to as a “snake bite” due to the usual pattern of two punctures on each rim bead directly across from each other which reminded someone of a snake’s bite, thus the name.
A tubeless tire has no tube, so nothing to pinch against the rim means no pinch flats……usually! One still can pinch the sidewall against the rim beads, but this is very unusual.
But what about punctures? Well, this is where sealant comes in. Sealant- some substance that seals punctures and seals up non-UST tire carcasses so they can be air tight, is a product that comes in many forms. Usually some form of latex sealant is most popular, however glycol based sealants are also somewhat popular for cycling. At any rate, the sealant seals up punctures, small tears, and holes….sometimes…and allows you to finish out the ride.
So, sealant combined with a tubeless tire greatly reduces the chances for flat tires. This is perhaps the single most popular reason for average mountain bikers to run tubeless tires, but there are other benefits.
Tubeless tires, since they do not pinch flat very easily, can be run at slightly lower pressures, enhancing traction. Also, since there is no tube to cause rolling resistance, this makes lower pressures even more attractive. A tubeless tire run at a slightly lower pressure than a tubed tire can get better grip, ride smoother, and have similar or less rolling resistance than the tubed tire. Reduce the pressure on the tubed tire to match and generally you will increase the likely hood of a pinch flat and greatly increase the rolling resistance.
Weight was an early reasoning for going tubeless, but this is not necessarily the number one priority of off road cyclists. Tubed tires, if the tire is a very lightweight folding type, can weigh less by far than a similar model that is tubeless. The extra butyl rubber necessary to make the casing air tight is the culprit. Now days though, there are a vast number of cyclists who convert standard tires to tubeless use by way of sealant. This has met with varying degrees of success and should be approached with caution. We’ll cover a few of the techniques used to do this in a later post. At any rate, tubed tire to tubeless tire weights are very similar these days, especially with conversions to tubeless type set ups.
To recap- Tubeless tires are a great way to avoid flat tires, get better performance characteristics, and may save some weight over a standard tube and tire set up.
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For more on Guitar Ted's series on 'Going Tubeless' here are a few links:
Going Tubeless: How to
Going Tubeless: Day to Day
Going Tubeless: Questions and Answers
Going Tubeless: The Future
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