Is it worth converting your mountain bike to tubeless?
All your tubeless questions answered
Tubeless tyre systems have massively grown in popularity for all sorts of off-road riding, but it can often be confusing as to exactly what the benefits are and if it's worth doing. If you're wondering whether to make the switch to tubeless, here's everything you need to know about the benefits and the drawbacks of ditching tubes on your bike.
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While we're big fans of running tubeless and do so on almost all our bikes, it's not a simple case of fitting and forgetting about ever having a puncture again, so we'll cover both the positives and the negatives of going tubeless, as well as some of the commonly asked questions.
What are the benefits of going tubeless?
- Pinch punctures are virtually eliminated
- It's possible to run lower tyre pressures for improved grip
- Even multiple thorns are unlikely to cause issues
- It's generally much lighter
What are the downsides to going tubeless?
- Sealant is relatively costly, dries out eventually and will need replacing
- It's still possible to puncture so you'll need to carry a tube and/or repair kit anyway
- Running lower pressure can leave your rims more vulnerable to damage
- Changing tyres is a messier process and some wheel/tyre combos are hard to seal
The main thing to know when you switch to tubeless is that it's not going to stop you from ever having another puncture. While pinch flats - where the tyre is hit so hard that the tyre compresses enough that bead of the rim cuts through the inner tube - are eliminated, you can still have a pinch flat (of a kind) by cutting through the tyre casing itself, though obviously, this is much harder to do.
Tubeless setups are also virtually impervious to thorns - it's not uncommon to switch a tyre after running it tubeless for some time and discover a high number that have penetrated to the tyre without you noticing any effect - but if you put a big enough hole or tear into your tyre, the sealant is unlikely to seal and it'll still go flat if left alone.
Another oft-touted benefit of tubeless is that you can run lower tyre pressures, which is true to a certain degree. You will still be limited by the fact that going too low will create a lot of tyre squirm and roll that damages handling, increases rolling resistance and could even end up with you tearing the tyre off the rim. It's better to think of it that tubeless allows you to run the correct tyre pressures for your weight, tyre casing and riding style without needing to overinflate them to protect fragile inner tubes.
Commonly asked tubeless questions
Is tubeless lighter than tubed?
The short answer to this is yes. We bought a couple of standard Specialized innertubes, one 650b and one 29", both for tyres up to 2.4" wide, weighing 199g and 205g respectively. We then chucked a Muc-Off long tubeless valve stem on the scales plus 120ml of Orange Seal Regular sealant (enough for a 29" tyre) and the combined weight was 121g, which isn't a bad weight saving, though this assumes a number of things.
Having a tubeless ready tyre and a rim tape has a weight penalty over non-tubeless tyres and old style cloth tape, but when researching this article, we found it extremely hard to find a decent quality aftermarket non-tubeless ready tyre that we could use to compare with a tubeless ready one - and the same went for rims, of which all but the cheapest tend to come pre-taped nowadays.
Most sealants will seal up a non-tubeless tyre if you chuck a bit extra in there and even converting a non-tubeless rim to tubeless doesn't have much of a weight penalty - fag packet calculations suggest using a double layer of Gorilla Tape will add about 50g for a 29" wheel.
So, while the weight savings aren't huge and very much depend on what your stock setup is, but they do exist. Regardless, tubeless is best viewed as a way to protect yourself from the faff of frequent punctures, rather than as a way to drop any significant weight from your wheelset.
How much does it cost to go tubeless?
The answer to this very much depends on what you're starting with in the first place. If you've bought a new bike and it has tubeless ready rims and tyres plus some tubeless valve stems supplied with it then you'll be good to go with the cost of around 250ml of sealant, which is around the £15 mark from a respected brand.
If you have tubeless ready rims and tyres but no valves, those can vary from around £7 for basic brass valves to £23 for fancier, lighter aluminium valves such as the Muc-Off items we mentioned earlier, which come with a number of differently shaped rubber seals to better fit as many rim shapes as possible.
If your tyres aren't tubeless ready, then many sealants might still make them airtight enough, but you'll likely need to use more sealant to do this, which is why we always recommend getting more than you think you need as splashing a load more in will often get you out of trouble. Tubeless ready tyres do tend to inflate and seat much more easily, so if you upgrade to one of those, look at about £40 per tyre, depending on brand.
If you don't have tubeless ready rims, this is where things can get expensive, as a new wheelset isn't cheap. However, it is possible to use a rimstrip tubeless kit to convert non-tubeless rims to tubeless and these usually come with tubeless valves and often sealant too, making them an easy way to get set up. If you need one of these, budget around £40-£70 depending on the brand and what's included.
That said, the cheap way to do it is to use something like Gorilla Tape to seal your rims - indeed, it's what we usually do. A 24mm wide, 9m long roll costs about a tenner and you can usually do four wheels with it.
What different types of tubeless system are there?
This is where things can get a bit confusing, as 'tubeless' and 'tubeless ready' or 'tubeless compatible' can all mean different things.
Tubeless usually refers to UST or 'Uniform System Tubeless', which is the original mountain bike tubeless tyre standard. It uses special rims with no spoke holes in the bed and tyres with a thicker, airtight casing and special bead, all built to such an accurate tolerance that they don't need sealant, though in practice it is usually run with a little bit to prevent thorns from causing air loss. However, it is expensive due to the precision fit needing tight tolerances, generally heavier thanks to the airtight layer in the tyre and has generally fallen out of favour these days, despite being the most secure and easiest to fit by far.
Tubeless ready, tubeless compatible and similarly named systems do not follow the strict tolerances required by the UST standard, especially when it comes to tyres. With a tubeless ready tyre, you'll need to use sealant to make the tyre airtight and you'll often need to use a blast of high-pressure air to get the tyre bead locked (seated) onto the rim when you're pumping the tyres up. The same goes for tubeless ready rims, which usually have a drilled rim bed for ease of manufacture, but use a tape or liner layer to make them airtight in conjunction with sealant.
You can run tubeless ready tyres on a UST rim but you'll need sealant and you can run a UST tyre on a tubeless ready rim, but again, you're likely to need sealant to keep everything airtight.
How big a hole can tubeless sealant seal?
This one is a bit of a piece of string question, as it can very much vary. We've seen small punctures absolutely refuse to seal due to the tyre, sealant and puncture location simply not wanting to play together and we've also seen tyres peppered with thorns and with mighty holes and gashs in them continue on with barely any air loss.
Basically, most thorn holes will seal quickly and without air loss with a decent sealant and you're best off leaving them stuck in there, especially if it's a biggy. Small 5-8mm cuts and holes tend to seal more often than not too, but it really does depend on the location and the tyre, with a more robust heavy duty casing being less likely to cut in the first place and more likely to seal when it does.
Of course, if you use some tubeless bungs, it's possible to repair some pretty heavy duty holes and cuts in a tyre without needing to replace it or remove it and fit a tube, so that's worth bearing in mind.
How often should I change or replace the sealant?
Again, this very much depends on what the manufacturer says and the conditions the bike is kept and used in. Hotter temperatures will generally dry out the sealant more quickly, rendering it more likely to lose air pressure over time and also lose it's ability to seal new holes.
Manufacturers reckon anywhere from two months to six, but it's often best to take a look and see whether your sealant is still liquid every couple of months, with some clever systems on the market such as Milkit's valves and injector that allow you to do this without having to take the tyre off. Don't do it and you'll probably have to pull a great big ball of solidified sealant out of your tyre the next time it goes flat and won't seal again.
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