A tyre needs replacing when the tread is worn smooth, the sidewall is cracked or cut, or you want a different tyre for the season. Tread usually lasts 1,000-2,000 km, and winter salt and grit age rubber faster.
The job takes about half an hour on any road, mountain or e-bike. Buy a tyre of the same diameter and a suitable width, plus a new tube.
What you will need
Important: Keep all lubricants away from the tread, brake discs, pads and the rim braking surface. If any gets there, wipe it dry and degrease before riding.
Step 1
Remove the wheel
Shift onto the smallest rear sprocket. Release rim brakes; with discs, do not squeeze the lever while the wheel is out.
Open the quick release or undo the axle nuts. If the nuts have seized with dirt and moisture, apply WD-40 Multi-Use and wait 2-3 minutes. For the rear wheel, pull the derailleur back and lift the wheel out of the chain.
Step 2
Deflate and unseat the bead
Let all the air out, even if the tyre looks flat. Push the tyre into the centre of the rim all the way round so the bead comes off more easily.
Hook a lever under the bead opposite the valve and clip it to a spoke. Insert a second 10-15 cm further on and run it round the rim until one bead is off.
Step 3
Take out the tube and inspect the rim
Push the valve out of its hole, pull out the tube, then remove the second bead by hand.
Check the rim tape covers every spoke hole; replace it if shifted or torn, or the new tube will puncture from inside. Wipe grit off the rim.
Step 4
Fit the new tyre and tube
Check the rotation arrow on the new tyre and seat the first bead on the rim. Put a little air in the tube so it holds its shape, fit the valve through the hole and lay the tube inside the tyre all the way round.
Work the second bead on with your thumbs from the valve both ways. Ease the last section over with a lever, taking care not to pinch the tube.
Step 5
Inflate the tyre
Pump to half pressure and spin the wheel: the sidewall line should run evenly along the rim. If the bead sits low, deflate and adjust.
Inflate to the pressure shown on the sidewall. On tubeless tyres skip the tube and add sealant before seating the last part of the bead.
Step 6
Refit the wheel and service the drivetrain
Refit the wheel, the rear one over the smallest sprocket. Tighten, reset the brakes and check the wheel spins true without pad rub.
While the bike is on the stand, clean the chain and apply WD-40 Bike chain lube, and protect the quick release and axle threads with a thin film of WD-40 Smart Straw.
Tip: Carry a spare tube, two levers and a mini pump. If punctures keep recurring, run your fingers round the inside of the tyre: a sliver of wire or glass in the tread often punctures every new tube.
What next
Inspect tyres after winter and then monthly for cracks, cuts and wear. Check pressure weekly, especially in the cold. Treat threads and quick releases with WD-40 Multi-Use once a season so they do not seize.
These uses come from the experience of WD-40 users in many countries. Always follow the instructions and warnings on the product label.
More guides in «How to use».