NO MORE FLATS

How to make your bike puncture proof, with Steve Peat

TUBELESS PLUS SEALANT

We have so much more tech to help to prevent flats these days and tubeless sealant, combined with tubeless tyres, has probably been the biggest game changer. Tubeless sealant is a thin (usually latex-based) liquid that creates an airtight seal between the tyre bead and rim wall so you can get rid of those heavy inner tubes. It’ll help you seat a tyre, then the residual liquid sealant left inside is flung to the outside when the wheel spins. This means if you do pierce the tyre, the pressurised sealant will squirt out and block the hole before much (if any) air escapes. Most of the time you won’t even realise you’ve punctured.

No two punctures are the same, so it’s still possible to get a puncture that doesn’t seal with tubeless sealant, and in spite of all of the above advice. Chances are it’ll be on the sidewall because punctures on the top of the tyre are more likely to seal themselves as that’s where the sealant gets flung to when the tyre spins. Most tyres only have dual-ply casing on the top of the tyres too, so the sidewall and the bead is the vulnerable spot.

You may need to use a tyre plug to get a reliable seal. Tyre plugs (aka bacon strips, aka dog poos) are super-sticky strips of rubber that are usually 1.5mm or 3mm thick – push one into a puncture using the small metal fork tool. This gives more structure to the hole and works together with tubeless sealant to achieve a reliable seal.

TYRE PRESSURES

Pinch flats (aka snake bites) were the most common reason for punctures back in the day because we hardly had any suspension and sometimes we had to run pretty low tyre pressures to get grip in wet conditions. If we pumped our tyres up too hard in dry conditions we ran the risk of slices and cuts from scuffing rocks or even rolling over thorns.

Tyre pressure, then, is crucial for helping prevent flats. Run pressures too low and you’ll probably get a pinch flat or roll the tyre off the rim. Run the pressure too high and sharp rocks or thorns will more easily puncture the tyre, plus it’ll reduce your grip and comfort.

How do you get it spot on then? There’s no right answer because there are so many factors affecting the optimum pressure – how rocky or fast the trail is, the weight of you and the bike, the wheel size, your riding style and skill level, the tyres you’re running, and plenty more all determine the ideal pressure. The only answer is trial and error – buy a decent pressure gauge and start experimenting. Start at around 22psi in the front and 24psi in the rear and go from there.