If you want to start a fiery debate before your group ride, mention tyre pressure. The perfect tyre pressure is a controversial conversation that can get pretty heated if there are big differences in the how-to.
The pressure of your bike tyres, just like the rest of you bike set-up and clothing is all about one thing: How you feel when you ride.
There are plenty of recommended pressures for your inflation, however, they are really more of a guide rather than a command, and there are a few reasons why.
Variables that affect your ride speed and comfort:
Professional riders go way over the recommended pressure, running around 120psi or higher, going into the 140psi for a race with good weather and smooth, flat roads, and they usually have less body mass, so those numbers are exceptionally high. It’s not really about whether this makes your bike faster, but if it feels faster.
If you are running a narrow tyre then yes, it needs to have a higher psi to give it enough flex on the rotation as well as over bumps and potholes, however, there is a price to pay for that and it’s in the road vibrations. Recent studies have shown that vibrations in your body actually steal energy from your performance, and even the smoothest of roads will cause some vibration.
If you are riding shorter distances, like an ITT, then you will have enough power to overcome the energy loss on narrow tyres, for longer distances though you are really going to suffer, unless you have incredible fitness, which is why the pros are happy to slog it out.
For more casual rides or relaxed competition the best bet is to go for wider tyres that have more grip on the road. The extra rubber will absorb those vibrations, making your ride much more comfortable as well as more efficient. The extra width also means you can get away with lower psi.
For road bikes, if you are running your psi anywhere between 80 and 110 you can rest easy knowing your tyre pressure is normal (e.g. 23mm tyres). So saying you can get good efficacy on a well-maintained road at 60psi when running regular road tyres.
If you are riding a mountain bike (i.e. 2.1-inch) then you want even more suspension, which means flatter tyres, so look for a range between 25 and 35psi although you might need as high as 40psi if you are riding on smoother sealed roads. Bounciness off road will cost you a lot of energy so you want to make your ride as smooth as you can.
For hybrids then 50 to 80psi works best, although for rough road surfaces you might want to avoid the really low pressure zones as it may increase your chance of punctures, as well as the really high pressure zones which will create shock and vibration.
Most people dial in on a particular pressure that is effective and comfortable for them and stick to it. You’ll want to check your pressure before every ride, find the one that you feel most confident with and and keep it at a consistent level. You want to find a blend of comfort, grip and speed.
Under different circumstances your ideal tyre pressure may need to change temporarily.
When raining you will encounter more resistance from a wet road so it’s a good idea to drop your usual tyre pressure by 10psi.
If you ride a concrete bike path it will be smoother than a bitumen road so you can increase your psi by as much as 10 compared to a road ride.
Lower your usual tyre pressure by 10psi for chip rock or a potholed surface.
If you are expecting a road with a lot of curves, hairpin bends and quick descents, drop your usual pressure by 10psi to give you more responsiveness.
Tubeless tyres can run well on incredibly low pressure. You can drop as much as 20% compared to a latex inner tube.
Do run your front lower than your back, even if only slightly, as it will help balance your load. The back wheel takes more of your weight than the front, and if you have saddlebags or a backpack, even more so. (e.g. front 80psi, back 90psi)
Don’t sweat it too much, your pressure is probably not as accurate as you think. Even if your floor pump is brand new your actual tyre pressure is only roughly what the gauge reads. If your pump has been around a while or gets thrown in the back of the car or knocked around the track a lot, chances are the reading isn’t that accurate, although it will be consistent.
If you did want to know exactly how much air you are putting in your tyres and keep it consistent ride to ride then you are best to buy a stand alone pressure gauge that is not attached to your bike pump that can read the pressure at the valve.
Keeping the pressure in your tyres and off your body for a smoother ride? That’s freedom!