Many cyclists think about the latest upgrades they should make to improve their bikes. However, something as simple as a few psi less in your tyre pressure, can actually make a great difference to your cycling experience. Having the right or ideal tyre pressure for your tyres is important before you set off riding the trails or hills. Too full a tyre could cause you a flat because of sudden explosions; too little air could mean your wheels are scraping the ground as you roll. The ideal way to inflate, would be to do so against your weight and the type of terrain you’re conquering.
Let’s start with the Variables:
Tyre pressure by itself is quite a branch of science. However, it is not insurmountable. The best way to do it, according to experts, is to weigh yourself and experiment with different pressures to fit your weight.
Weight: The main consideration. Your weight as rider affects the amount of psi the tyres should carry.
The 40-60 PSI Rule: Ideally, psi distribution should be 10-20% lower on the front tyre than the rear. Say 60-90 psi. This is because the rear tyre carries more of the weight than the front.
Terrain: Paved or unpaved roads? Smooth bitumen or rough chipseal? Depending on the terrain, you need to adjust the tyre pressure accordingly. Traditional wisdom states “higher pressure = lower rolling resistance”. Properly-inflated tyres conform to the road bumps and imperfections and absorb them because of space in the tyres.
Smooth: Higher psi, no problem. Hard tyres flex less on smooth surfaces and you roll faster with fatter tyres because of less contact with the road.
Rougher Roads: For rougher roads, a lower psi is better – there’s “space” in the tyres to absorb bumps and shocks. Having over-inflated tyres on bumpy terrains causes vibrations to be transferred to you, the rider. As a result, you end up taking a rougher hit.
Conditions: Rainy days result in wet roads. If you’re going out after a thunderstorm’s ended, lower your psi by 10 to accommodate the moist terrain. Remember, more air creates more bounce; less air gives you space to roll over obstacles. The balance lies in finding a right median between air and space.
Tyre width: The wider the tyre, the lower the pressure. Road bike tyres typically use the highest psi , followed by hybrid bikes then mountain bikes. However, tyre pressure also depends on the size of tyres used. A mountain biker may swap his fat MTB wheels for hybrid ones, thus using a higher psi for narrower wheels.
Most Typically, We Casual Cyclists
feel the flats in our tyres, turn in to a bike shop and use their pumps to inflate our tyres – Free Of Charge. The upside? Yay if they offer you a floor pump – you can check the meter reading. Nay if they simply offer you a wall-hose sort of pump – that’s automatic and does not come with gauge readings. In this instances, what I normally do is press my tyres to estimate by hand if the pressure’s enough. Following the 40-60 rule, I ensure that my front tyre has a little less air than my rear tyre. And following the -5 psi rule, I allow a bit of space in both tyres unless I’m taking really smooth roads (a somewhat oxymoron despite Singapore’s well-paved roads).
Check out this video for a really cool fast two-minute method on inflating your tyres.
Some Common Issues with Tyre Pressures
50-50 tyres: 40-60 is a more appropriate distribution equation for road riders. Mountain bikers may want to follow this formula with some deviations depending on their terrain and needs. Generally, the rear wheel bears more of our weight than the front, hence more air there. When you tackle bumps, the front wheel absorbs the shocks first, hence more “space” is needed there, less air.
Floor Pumps: Not all floor pumps are supported by accurate gauges. Floor pump gauges measure air pressure inside the pump and not the tyre. It may register a 10 psi variance. The good news however, is that floor pumps are consistent in their air measurements. So you get a consistent wrong measurement, which is a little better than an inconsistent right one. The solution? Invest in a separate gauge. Go digital if you’re that anal about highly accurate readings. If not, a normal one would suffice.
Over-inflation: When you over-eat, your belly bloats and you feel uncomfortable until the food has digested. Same principle with tyres: when you over-inflate them, they’re more likely to explode due to built-up pressure. Over-inflated tyres are poor at taking rougher terrains as they’re not able to deform enough to “conform” to its contours, thus transferring the shocks and vibrations to you, the rider. Reduce the “ego” by 5 to 10 psi helps – a slightly “hungrier” tyre is more eager to eat up the road.
Wider tyres have a higher volume and less rolling resistance. Imagine a 29 inch wheel crusading over bumps while a 25 inch one having difficulty with the same terrain. Hence, decrease air pressure for wide tyres. Thinner tyres require more pressure to make up for a lack of volume and width in supporting their rider. Remember that.
In light of the above pointers, you can enhance your ride performance by simply paying more attention to this oft-overlooked detail – tyre pressure. Spend a little more time on experimenting; probably buy better tyres if you need to. Above all, lessen the pressure on the poor tyres if you want them to perform. Pun intended.
Read this article if you want to get into the advanced mechanics of tyre pressure.
More news at http://www.togoparts.com/magazine
Submit your articles you wish to contribute here or click on the banner below.
WRITE to us at email@example.com if you have any suggestions or feedback regarding content.
Click on the Lucky Draw banner to register for the Grand Lucky Draw happening @ Togo Bike Fest 2017!