Air is an integral part of the structure of your wheel-tyre unit.
Ensuring that your tyre is inflated to the correct pressure is key if you want them to give both optimum performance and durability when you’re out riding.
Earlier this year, our Brand Manager Graham helped Bennetts put together a Complete Guide to Motorcycle Tyres.
From that article, here’s a few things you need to know about tyre pressures:
- How Do I Check My Tyre Pressures?
Always check your pressures when the tyres are cold. As you ride a bike on the road and your tyre heats up, this can increase pressures by around 0.5 bar (close to 7psi). It’s important that you don’t let your tyres down to remove this excess pressure, as they’ll be under-inflated next time you ride.
Make sure you use a quality stand-alone pressure gauge, not the one fitted to your pump, or on an airline. Garages offering free air are not required to calibrate their gauge.
- What Tyre Pressure Should I Use On My Motorcycle?
Your bike’s owners’ manual will tell you the recommended pressures, also occasionally displayed on a sticker on the swing-arm or hugger. Use them – your bike will have been thoroughly tested to find a safe recommendation based on getting heat into the rubber, and the load you’re likely to carry.
Incorrect pressures reduce the life of your tyres, and can affect the handling; if you run them low, the contact patch can be reduced – not increased – because the tyre deforms, lifting the middle section away from the road. They’ll also overheat more easily and can be damaged. If you over-inflate your tyres, they’ll wear unevenly, handle poorly and give an uncomfortable ride.
You might find different pressures recommended for different loads and riding – Continental recommends that you ride at the highest pressure stated in your owner’s manual. If you don’t have the bike manual, check your tyre manufacturer’s website.
- Should I Reduce My Tyre Pressure In Wet Or Bad Weather?
No. Your tyres have been designed to work at a specific pressure. Some people reduce the pressure of their tyres in the winter, believing they’ll offer increased levels of grip. What actually happens is that they get warmer, because they will move around more. However, the size of the contact patch will actually be reduced due to deformation. This means that the tread pattern will perform less efficiently when clearing water for example; plus you’ll get less miles, and it could be potentially dangerous.
- Should I Reduce My Tyre Pressure For A Track Day?
If it’s your first time on track, then no – just get out there and enjoy it.
Because manufacturers test bikes for safe pressures on the road, if worked very hard, the tyres can get too hot. The air inside your tyres is, of course, the same as the atmosphere around us – it contains water. As the temperature inside increases, the water expands, and the pressure increases.
Some people avoid this by using nitrogen, but as you don’t get that ‘bedding in’ feeling you expect from a cold tyre, it can feel odd when pulling away – the bike can feel ‘wooden’ at first, and once a bike feels odd, a rider can often lose confidence in it.
How far you need to reduce the pressure of your tyres on track will depend on how hard you ride. Keep in mind that you don’t need to reduce them for any form of road riding, so be honest about how hard you can push you bike. Graham’s recommendation, if you are riding hard, would be to take a pressure gauge with you – ride the first session at road pressures, then check the tyre while it’s still hot. As a rule of thumb on a sportsbike, reduce the rear to 42psi if it’s above that as soon as you get in from your opening session while your still is still hot, and drop the front to 36psi. At the end of each session, just check the hot pressures again and reduce only if they’ve gone over 36/42psi as you get quicker through the day. Just remember to pump them back up when they’re cold at the end of the day before you ride home.
True racers will go a lot further – the recommendation for a Continental race tyre is just 26psi when it’s hot! This takes into account just how hard the tyre will be working under race conditions – this is way in excess of any track day pressures, even in the fast group, and would feel awful to a rider who wasn’t trying to win a race.
Interestingly, Graham has found that for every 10°C change in temperature, the tyre pressure will typically change by 1psi, which as a percentage of the overall pressure is significant. If your pressures are off, you won’t be getting the best out of your tyres or your track day – and you’ll be wasting money and track time.
If you’re unsure about any aspect of your motorcycle tyre, always ensure that you speak to a specialist for further advice.