One of the biggest headaches involved in riding a bike is getting punctures. The loss of time, the effort, frustration, and expense of repairing a rubber inner tube can really ruin a day on the trail or make you very late for work.
I know this from personal experience. Once on a long ride, a piece of glass managed to worm its way between the tire and the rim of my front tire, which quickly deflated. On inspection, the tube was punctured in five places - my heart sank. Assessing the damage, I chose to replace it, rather than wasting hours fixing multiple ragged holes, then dealing with the liability of a tube with five patches on it. This happened in the city and close to home, so finding a replacement tube was easy. Had it happened out on the trail, it could have been a very different story.
In recent years, a revolution in tire technology has taken place. Its innovations now extend across road bikes and hybrids as well as trail bikes. The simple question that inspired this revolution was - can we do away with inner tubes altogether? Automobiles have been using tubeless tires since 1955 - why have bikes taken so long to catch up?
Some clever yet simple design ideas came to the rescue. By changing rim, tire, and valve styles slightly, and introducing liquid sealant, the new tubeless tire was invented. Although favored mainly by off-road bikers around 2012-2013, this tire type has become increasingly common among all cyclists. It's true to say that inner tubes probably have their days numbered!
Let's have a look at the pros and cons of inner tubes versus tubeless tires, examine how to fit a tubeless tire, and answer some FAQs about the technology.
Tubed vs Tubeless: What's the Difference?
Tubed tires have a flexible rubber inner tube, with a fitted, sealed valve. The tube sits between the rim and the heavier tire casing and is inflated to fill the space and push the tire out. If a puncture occurs, these tubes can be removed and either patched or replaced. Both procedures can be difficult and time-consuming. Furthermore, repairs are not guaranteed to produce an airtight seal, no matter how thorough you are.
Tubeless tires create a seal between the tire and the rim and remove the necessity for an inner tube. They require the rim to be fully sealed (usually with specialized rim tape) and a unique type of valve is fitted, featuring a removable core. This allows the fluid sealant to be injected into the tire in sufficient quantity to run around the inside of the tire, maintaining an effective seal by filling any punctures that occur and hardening. On such bikes, normal tire pressure is maintained, with 1-2 ounces of sealant injected into each tire.
Pros and Cons of Tubed Tires
The only real pros of continuing to use tubed tires are custom. If your bike has inner tubes, you'll be used to fitting, patching, and replacing them. If the effort and difficulty of this procedure are acceptable to you, then there may be no urgency to switch technologies. However, you should take a look at the benefits of tubed tires before resisting change.
The cons of tubed tires are several:
- They are difficult to fit, and the tire is tricky to fit into place around them.
- They are prone to puncture and once punctured, difficult to repair.
- Constantly replacing them can be expensive.
Because inner tubes are made of thin rubber (or latex in older models) they puncture easily. Once punctured you have to remove both tire and inner tube, locate the puncture (or multiple punctures), patch, test, inflate, wait, and then replace the inner tube, before refitting the tire and re-inflating it. This is a laborious process and one that can be immensely frustrating (if you've missed a subtle second tear, for instance).
Also, inner tubes can add up to 18 ounces of rotational weight to your tires, which could make all the difference if you're racing, or going for a long ride in challenging terrain.
Pros and Cons of Tubeless
Tubeless tires have many advantages. They are designed to be puncture-resistant and retain this quality when used with reduced pressure. Riding with less-inflated tires increases grip on technical terrain and makes for safer mountain biking. Punctures will certainly occur less frequently on such a tire, assuming it is correctly fitted. For more on fitting a tubeless tire, see below.
When they do occur on a tubeless tire, punctures need not necessarily require much labor. Puncture plugs now exist to temporarily fix a tear or hole, so that you can get home quickly. As noted above, tubeless tires can be significantly lighter than their tubed counterparts.
The only real cons are that setting-up tubeless tires can be a little more complex and pumping them up is something not best achieved with a hand-pump. A compressor should be used, or a floor-pump, for maximum efficiency and to ensure correct tire pressure. Different types of tire require a very different pressure, ranging from just 25 - 40 psi for a mountain bike to 80 to 130 psi for a road bike.
You also have to make sure your bike's tires are tubeless-ready and that the rims are properly sealed. If in doubt, take your bike to a repair shop and ask if it can be reasonably converted. If you choose to do this yourself, instructions are below.
Here's a video that discusses these issues in depth.
Frequently Asked Questions
What's faster, tubes or tubeless?
Because tubeless tires are generally lighter, they should offer less rolling resistance. When you cycle, you are overcoming several different forces and impediments to forward motion including gravity, friction and the weight of rider and bicycle. All these factors, plus a coefficient specific to each brand and model of tire, combine to produce what is called rolling resistance.
Lighter tires minimize rolling resistance - they turn with less effort on the part of the cyclist. As this article in Cycling Weekly shows, this is especially evident at lower tire pressures, such as you might choose on a mountain bike.
What is a valve stem?
This is the metal valve that allows air to be pumped into the tire and then either springs closed when released, or is kept closed by the pressure inside the tire. On an inner tube, this is attached and pre-sealed. In a tubeless bike set-up, the valve must be fitted and sealed by hand.
On a tubeless tire, a special kind of valve is required, one which contains a removable core. This allows sealant fluid to be inserted through the valve, either when initially fitting the tire, or when topping up the sealant. Make sure that the sealant is circulated around the base of the valve when you fit the tire, as air can escape here otherwise.
What does tubeless ready mean?
Tubeless-ready tires and rims are manufactured specifically for tubeless use. They are designed to achieve a perfect seal between tire and rim. Tubeless-ready rims are pre-sealed so that air does not leak from the places where the spokes connect to the wheel, or from the edges of the rims. Tires prepared in this way may not need taping to achieve a good seal or they may come pre-taped for this purpose. If in doubt about whether your rims or tires are tubeless-ready, consult the retailer or manufacturer.
What is rim tape for?
You can convert non-tubeless ready rims for tubeless tire use by running tape around the inside of the rim. This must be done carefully to avoid air bubbles or folds. The tape must not extend beyond the edge of the rim and must be applied evenly over all metal surfaces within the rim. Specialist tape can be obtained but you can also use Gorilla Tape. See this video for tips on how to convert rims in this way.
Once the tape is fitted, you must make a small X-shaped incision above the hole in the rim for inserting the valve through. Then fit the valve, as per the provided instructions. These valves usually come with a small tool for removing the inner core, so that you can then insert the sealant.
What are the two methods for fitting tubeless tires?
These are commonly called the Wet and Dry Methods.
The wet method involves half-fitting the tire, then squirting the sealant into the lower arch of the rim. Simply rotate the wheel as you fit the rest of the tire. Once the tire is fully in place, use an air compressor to inflate the tire. It's called the wet method primarily due to how messy it can be - the sealant can drip from the wheel as you fit the tire. You should definitely do this on a surface you can easily wipe clean and wear old clothes.
The dry method means that you fit the tire completely then squirt in the sealant through the air valve collar (with the core removed). Then insert the core and inflate the tire as normal. You may wish to use some soapy water to lubricate the sides of the tire so that when inflated, the tire beading easily slips and pops into the rim.
The dry method should prove a little easier and less messy than the wet method.
How is the tire sealant used?
A small quantity of sealant coats the inside of the tire and slips into the edge between tire and rim, creating a perfect seal. The rotational movement of the tire spreads the sealant evenly, meaning that you only need 1-2 ounces of it at a time. Do note that it will dry up over time, so will need to be topped up roughly every two months.
It is a bad idea to mix different brands of sealant in the same wheel, as they can react together unhelpfully. When you have added your sealant, make sure you roll the wheel around in your hands, holding it flat and turning it over, to ensure a good initial spread. Then leave the tire flat overnight so that the sealant seeps into any imperfections in the rubber. If removing your tire for inspection, take the opportunity to clean the interior of the tire of any dried-up or old sealant.
How do I inflate tubeless bike tires?
As tubeless bike tires are much harder than rubber inner tubes, fully manual pumps should be avoided. Manual floor-pumps can be used at a pinch but compressed air systems work best. These come in four basic types:
- air compressors where you pump air into them, then release this in one blast into your tire.
- portable systems you can fill with compressed air at a gas station, then use as above.
- miniature CO2 canisters - if you use these, check that CO2 is compatible with your sealant to avoid unhelpful interactions.
- floor-pumps that send the air directly into the tire as you pump.
If you use the latter type of pump you may want to check intermittently that the tire is popping correctly into place. You should hear an audible snapping sound as the rubber beading hooks into the inside of the rim. You'll also want to rest your arms from time to time!
Should I go tubeless on my mountain bike?
Tubeless tires are a great choice for mountain bikes. You can ride on less fully-inflated tires, providing a much-improved ride quality and better traction, whilst still avoiding punctures. That said, you should always bring puncture plugs and a spare inner tube just in case you do get that rare puncture out on the trail.
There are very few reasons to stick with inner tubes, provided you are happy to either pay for professional tubeless tire installation or do it yourself. Fortunately, there are many very helpful online videos explaining the whole process, such as this one.
Once you've gone tubeless, the consensus among serious bikers is that you're unlikely to return to inner tubes. Perhaps it's time to commit to change?