Tubeless tyres have become de rigueur for mountain bikers and are rapidly gaining in popularity with road cyclists.
The technology relies on an air-tight seal between the tyre and wheel rim. A fluid poured into the void between tyre and wheel that would be occupied by an inner tube on a conventional ‘clincher’ rim seals the tyre in the event of a puncture.
In the latest of our video maintenance edits, we check in with Jon Hayes, mechanic at independent bike shop, Ride, to learn the simple steps necessary to fit a tubeless tyre.
Applying the rim tape
Jon demonstrates the process with a Stan’s ZTR Alpha 400 rim. The American firm pioneered tubeless technology and their products occupy a dominant position in the mountain bike market.
Stan’s proprietary ‘Bead Socket’ technology provides an airtight seal between tyre and rim, but to complete the process, it’s necessary with this wheel to seal the spoke holes too. Jon applies a length of Stan’s rim tape: a single-sided sticky tape. “It’s worth doing this at least at room temperature,” Jon says. “If you trying doing this in your garage, where it’s damp, or it’s cold, you’re going to have a job getting the tape to adhere to the rim.” Don’t be afraid to add a second layer of tape if using the Alpha series rims demonstrated here – Stan’s recommend it.
Jon anchors the tape with his thumb to help apply tension to the tape as he lays it over the spoke holes. The tension allows the tape to be applied smoothly, without wrinkles. “Apply pressure and work your way around a couple of inches at a time,” Jon says. “You can’t rush this part of the job. You need to go as slowly as you need to.”
“I can’t really emphasise this enough,” Jon says. “Air will escape very quickly from any areas that aren’t stuck down.”
Fitting the valve
Having applied the rim tape, the next requirement is to fit the valve. Because there is no inner tube, the valve is an independent item that is held against the rim with a lock ring on the outside and a rubber bung on the inside. Jon makes a small hole in the rim tape with a pick, and advises against using anything larger – doing so will only allow air to escape more easily.
Fitting the tyre
Tubeless tyres are specifically designed to create an airtight seal and must be used in this application. The example shown is a Schwalbe Ultremo ZX Tubeless. Jon begins by fitting one side of the tyre and checks to ensure the bead of the tyre is not hooked over the valve bung. Satsified that it isn’t, he continues by fitting the other side of the tyre, but stops short of the valve so he can introduce sealant to the void between tyre and wheel. Jon’s technique – making the section of the tyre closest to the valve stem the last to be mounted – is Stan’s recommended method.
Introducing the sealant
Jon pours the sealant into the supplied cup, and pours the sealant from the cup into the void between tyre and rim. He turns the wheel slowly and carefully to allow the sealant to flow around the circumference of the wheel. He completes the fitting of the tyre by hand rather than using tyre levers to avoid damaging the air-tight bead. Be very careful if you need to use a tyre lever, Jon warns, and use a plastic rather than metal one.
Inflating the tyre
Most bike shops will use a compressor to begin the process of inflation”It introduces a lot of air into the tyre very quickly,” Jon says. “It lets the bead seat very fast before too much air can escape.” It is possible, however, to perform the task with a conventional track pump, which Jon demonstrates. “Pump hard and fast, ” he advises. “Get in as much air as quickly as possible.” They tyre will ‘pop’ as the bead seats on the rim.
The tubeless system shown is from Stans, but others exist. Jon completes the edit by describing some of the competing systems, including those from Mavic, who use a sealed rim which doesn’t require tape, and Bontrager, who supply a clip-in, semi-rigid plastic cover.