Getintomtb – Tubeless

You may have heard the term “tubeless” in mountain biking and wondered what it is or how to go about it. We’ll do our best to explain.

In simple terms, Tubeless refers to running  your wheels with no inner tube. This is very similar to a car tyre, but bicycle tyres have a trick up their sleeve, with tyre sealant. A small amount (about 70ml) of sealant solution is added into the tyre, so that when something punctures the tyre, the sealant quickly fills the hole, allowing you to just keep riding. And it’s that simple – just check your tyre pressure and you’re good to go again. Most occasions you won’t even notice the puncture occur and it’s an amusing surprise when you’re cleaning your bike and find thorns sticking out of the tyre.

So are there any other advantages? Yes, starting with the ability to run lower tyre pressures, which increases grip. That increased grip also comes with a reduction in rolling resistance. When you run an inner tube you effectively have 2 layers of rubber contacting the ground. Running tubeless means there is only one, more supple layer, which snaps back from deforming quicker.

Can I run my bike tubeless? 

As long as your rims are tubeless compatible, you will be able to convert them to running tubeless. Normally rims will say if they are tubeless compatible – as a bare minimum the rims will need to be welded where they join (as opposed to pinned), but if the rims don’t have any clues, a Google search should either tell you definitively, or generally tell you if people have been successful or not trying (forms like Pinkbike or Singletrack are great for this).

How do I do the conversion? 

Pay a bike shop! Ok that’s a flippant comment, but it definitely worth considering for the initial conversion, as it can be tricky the first time and bike shops normally price the conversion very reasonably (especially if you use the opportunity to upgrade your tyres).

But if you’re game for trying it yourself, here’s what you’ll need:

  • Air tight rim tape
  • Valves with removable cores
  • Tyre sealant
  • An inflation device, such as as Airshot or an air compressor.

Whilst the final one is optional, it’s extremely hard work (or impossible in some cases) without one.

So first of all, you will need to tape the rim on the inside, covering any holes (normally spoke nipple holes). Get some suitable tape that is correct width for the inside of your rims – it needs to cover the spoke holes completely with sufficient spare on either side to maintain an airtight seal. There are lots of different tapes out there, but again your local bike shop is a good place to go, as they can advise on the correct width.

Remove your old tyre and inner tube and give the rim a good clean, so that the tape can stick properly to it. Then start the tape at least a quarter rotation away from the valve hole, pressing the tape on good and hard, making sure you cover those spoke holes. Go all the way round and overlap by at least a quarter turn past the valve hole before stopping. The valve fitting is one of the main things that goes wrong when setting up tubeless, so you want a double layer of tape over the hole.

Next use a small philips screwdriver to make a very small hole in the tape over the middle of the valve hole. Then push your new valve through this hole gently, letting the valve widen the hole just enough to let it through. If something goes wrong and the hole opens up too wide accidentally, don’t panic – apply a puncture repair patch over the hole and try again. That should maintain the seal.

Take your tyre and fit one side of it, like you would normally. Now pour in the sealant and fit the other side of the tyre. You are now ready to inflate it, which can be the tricky part! If the tyre is very tight on the rim, you might be able to inflate it with some quick strokes on a track pump, but normally you need an Airshot or compressor. The Airshot (or similar) are the best way, so we’ll describe that method.

The valve you’ve fitted will have a removable core – take some pliers and unscrew the valve core (grabbing as gently as you can, as the cores are bendable).

Fill up your airshot as much as you can with a track pump – try to get at least 100psi in it, ideally a bit more. Attach the Airshot to the valve body and turn the lever. The Airshot will dump its entire contents of air in one blast, which should inflate the tyre instantly.

Unscrew the Airshot and stick your finger over the valve hole as quick as you can, retaining as much air in the tyre as you can. Then refit the valve core, again trying to keep as much air in as possible.

Now continue inflating the tyre with a track pump. You want to get at least 40-45psi in the tyre to seat it properly – you should hear some loud pops and pings as the tyre seats in the rim beds.

Give the wheel a good shake and spin and generally turn it upside down and the back again to distribute the sealant round the inside of the tyre. If possible leave the tyre for a good few hours before readjusting the pressure to the correct level for you.

What pressure? 

A Tubeless setup will run at lower pressures than one with inner tubes. As a starting point, take your fully loaded riding weight (so that’s all your riding kit, shoes, helmet, backpack etc) in lbs and divide by 7 and take away 1 for the front pressure and add 3 for the rear. So someone at 10 stone is 140 lbs and gives a front tyre pressure of 19psi and rear of 23psi. Those are just starting points though, so start there and go for a ride and see if you need a little more or less.

And that’s it – happy riding!