Switching to tubeless tyres can be messy, but it's worth it. Here's how.
Tubeless is the biggest advance in tyre technology of the last decade. As the name suggests tubeless wheel and tyre combinations have allowed cyclists to rid themselves of the butyl inner tube. This means improved road feel and when used in conjunction with tyre sealant, fewer punctures. The system isn't as clean or easy to set up as using inner tubes, but the long term benefits to the quality of your riding are, in our opinion, well worth the added investment in time and money.
1 Starting with standard rims. If you're lucky enough to have undrilled tubeless-ready rims you can move on to step 9. If you're running regular rims, with drilled rim beds for spoke nipple access, you'll need to remove the tyre, tube and rim tape. Give the rim bed a thorough clean with some soapy water and possibly some degreaser depending on how icky it is. Allow to dry thoroughly.
2 Applying seal tape. In order for a tubeless tyre to work, the rim must be made air tight. There are two methods to making an air tight seal. One is to use an adhesive tubeless tape like this one from DT Swiss. Line the tape up in the rim bed to one side of the valve hole, and covering the valve hole work around the rim applying the tape evening into the centre of the rim bed. Keep good tension on the tape as you go, as you're looking for a nice sung fit, with no ripples, folds or creases.
3 Join the ends. As you bring the tape around to the valve hole, where you began, make a neat trim to butt the two ends of the tape up to each other. Use a sharp point to pierce a small, neat hole through the tubeless tape through the valve hole - from INSIDE the rim bed in the same direction as the valve will be fitted, other wise you will lift the tape off the rim bed and risk ruining the air tight seal.
4 Fitting a one-piece rubber seal. If you're using a the type of tubeless rim tape that comes in a ready-made hoop, align the valve holes in the tape and the rim and drop a thin screwdriver through them to hold the tape and rim in position. This will allow you to fit the remainder of the tape without it creeping round the rim and its hole going out of alignment with the rim hole. Once the tape is in the rim bed, it's hard to lift out to realign.
5 Keep the tape tensioned. As you work the rubberised tubeless tape around the circumference of the rim keep a steady tension on the tape which will be slightly stretchy. This will give the tape fitted a good seat in the rim bed, and give you a little extra to flex over the final section of rim wall at the end.
6 Keep the tape centred. Make sure the tape is perfectly centred as it is laid down inside the rim well. This will help ensure an air tight seal of the rim bed and help the tyre bead 'find' the inner sidewall of the rim faster as you inflate. This is especially important if you're using a regular track or hand pump.
7 Keep the tape tensioned. As you work around the circumference of the rim, use your thumbs to keep an even tension on the tape. It's usually slightly stretchy and can be pulled to create enough slack to pop the final bit over the outside edge of the rim sidewall. It should snap into position with a tight, positive sound.
8 make sure it's smooth. When the tape is installed, go around the rim checking it's fully seated with no ripples, tucks, folds or creases where air can leak. Take a few minutes to get this right. Use your fingers or the rounded end of a small screwdriver handle to push the tape right down hard. If, after attempting to pressurise the tyre, the fit between the tyre and rim is too loose, you might want to add another wrap (or two) of tape to build up the rim bed depth and create a tighter and more effective seal between the two items.
9 Seat a bead. Time to go counter intuitive. Fit a regular inner tube into your tubeless tyre. Fit the tyre and inflate it until the tyre beads snap into place. Then deflate the tube, break the bead on one side of the tyre away from the rim and remove the inner tube. This means you already have one side of the tyre bead seated, halving the job air pressure alone will have to do.
10 Fit the tubeless valve. Ensure the valve's rubber foot is properly seated into the rim well. Often they're shaped and only fit to make an effective air tight seal one way. Add the necessary rubber O ring seals (if your valve uses them) and threaded lock rings and snug them down tight to make the valve assembly air tight. Remove the valve core.
11 Prepare the sealant. Draw sealant into a syringe fitted with a flexible rubber hose. This will fit over the valve stem and allow direct insertion into the tyre.
12 Squeeze the sealant in. With the rubber hose fitted over the valve stem (the threaded outer will grip the inner surface and stop fluid leaking out) you can push the fluid into the tyre.
13 There will be mess. Some sealant will seep out of the bead during the fluid insertion and tyre fitting inflation process. This is normal, and necessary for the sealant to fill the gaps between the tyre and rim. Wipe it away as soon as you've made the seal and got the tyre to pressure. The sealant is sticky and can leave stains on your frame, tyres and rims. Refit the valve core.
14 Spread the sealant. You can help the sealing process by giving the tyre and wheel, once prepped with sealant, a good jiggle. This moves the sealant around the entirety of the inner surface of the tyre. You can repeat this process once the tyre is inflated as well to help with the final sealing.
15 Inflate the tyre. Ideally you want to get a lot of air into the tyre as quickly as possible to blow the beads into the rim quicker than air is able to escape. This is most easily achieved with a home compressor, or one of the new breed of tubeless-specific track pumps that can be pre-loaded with a high-pressure blast of air. A standard track pump can also work, and if you've set up the system well and chosen your tubeless tyre and rim combination wisely, a hand pump can make the magic happen.
16 Check the pressure. It's not uncommon for tubeless systems to lose a few psi after installation, as the sealant works to plug all the microscopic holes in the carcass and union between tyre and rim. Top up any deficit and ride; that also helps finalise the sealing process. Doing this whole process indoors, in the warm, also helps. You should find the tyre holds pressure consistently after 24 hours.