Contrary to the general imagination, it is the moving parts of our bike that are most important in its performance! It’s no use having a super-exchange, a great suspension, a next-generation disc brake, if our central motion, crankshaft, hubs and wheels are of poor quality. So the first “upgrades” on our thinnings should be the moving parts.
From this, it is useless to have a wheel and tire of excellent quality, if we do not know how to use correct calibration. The purpose of this post is about how to correctly calibrate our bike tires, which is not as simple as it seems! Come on?
The first common mistake is not knowing the correct calibration of our tires. If you are filling your tires with a “floor pump” it probably has a watch that records the tire pressure. Most of the time, this watch records the current pump pressure, not the tire pressure. Only then can we have a big flaw in our calibration. We have reported errors of more than 10 PSI of difference!!!! To correct this error, the ideal one is a single pressure gauge, easily found in the market. There are even digital versions. With this, you fill your tire and check the calibration from a tire meter.
Each tire has its “PSI” gauge (pound force per square inch) and has the maximum allowable gauge size (see example below, whose value is 36 PSI)
Normally, we use the same calibration measure on the front and rear tires. However, our larger weight is concentrated on the rear wheel. So here’s another important consideration!
If You Want To Know How Much Difference You Can Have In Front And Rear Calibration, Take A Simple Test:
1-) Weigh yourself with all your uniform/clothing (shoes/sneakers included) holding your bike;
2) Put one of the wheels of the bicycle on the scale and support the other wheel in a block of the same size of the scale so as to leave the bike stable for you to mount it, and ask a friend to support you and your bike in this position, and Check the weight on the scale.
3-) Change the scale to the other wheel and do the same procedure.
The total amount should correspond to its static weight obtained in step 1, and the weight of steps 2 and 3 is to give you the percentage of total weight in each wheel. See the difference!
The bad news is that there is apparently no scientifically supported formula to adjust tire pressure based on weight distribution. This is just an instructive test because it shows you the difference in weight between one wheel and another, but it will not give you an accurate equation to adjust the tire pressure. It will only give you an idea of proportion.
The truth is, whatever the pressure of your preference, it will depend on a variety of things, including your choice of type of tires and style of pilotage. But from this test it is clear that you should not use the same front and back pressure. If you weigh 70 pounds, you have a 60-40 weight distribution, that would be 40 pounds on the rear wheel and 30 pounds on the front. So ideally you use less pressure on the front. 15 to 20% less pressure is enough to balance this difference.
One important thing: tires leak air over time. Do you check your tire pressure regularly?
“Butyl” chambers (the most common type) leak much less than the lighter latex versions, but they still lose a few PSI a week, especially if the bike stands still! You do not need to check the pressure before each pedal, but at least once a week. “Withered tires”, in addition to making the bike slower, are more susceptible to bores!
Our standard is almost always “over stuffing.” The maximum pressure listed on the sidewall is generally higher, and does not take into account any of the factors that influence tire pressure such as the size of the rider, the type of terrain, and other factors.
For a long time we have been “indoctrinated” into thinking that higher pressures offer less rolling resistance. And higher pressures also reduce the likelihood of holes. As we said above, this is true.
However, If You Have Switched To Wider Tires, You Must Lower The Pressure. Here’s Why:
Larger tires have a larger volume, so you should decrease the pressure proportionately. They also have less side wall deformation, which reduces rolling resistance compared to narrow tires at a given pressure.
Rolling resistance increases with lower pressure, but several studies show that in various road tires, rolling resistance increases only slightly, in the order of a few watts, even with pressures down to 60 PSI in Standard road. The biggest differences in rolling resistance are not in pressure, but in the type of tire you are using.
The lower pressure increases curve adhesion, in part by increasing the contact area.A low pressure tire also deforms more around the road surface, which is in part responsible for increased rolling resistance. But a heavily inflated tire will give you all the unevenness of the terrain. So when we use lower pressure, you get bonus: In addition to increasing the grip of your bike, you’ll also feel much more comfortable, especially on off-road paths!
Try wilting your front and rear tires, say 5 percent each ( percent, not PSI , because remember, front and rear are different and should be changed proportionately). Go cycling and see how the bike feels. If this is the case, decrease it a little more.
It may take a while, but by “finding” your tires’ ideal tire pressure, you’ll have to ride a more comfortable ride with a feeling of greater safety when cornering more closely, especially on tracks. If you notice the front wheel “bobear” a little in the curves, in the next roll increase the calibration a little more.
Then, when you find your ideal calibration, be sure to write it down and save this note!
But if you change the size and/or brand of tires, you must repeat this whole process again!