We know that this is one of the most common questions we encounter regarding the maintenance of our bicycle, whether it’s a road, mountain, gravel or electric bike. Having the correct tire pressure on your bicycle will improve the riding experience and the bike's performance. However, it can often be difficult to find the right measurement. This is because there are a number of factors, both mechanical and related to the cyclist, that mean the inflation pressure is not the same in every case. Among this first group of factors, we must highlight the wheel size, the tire width or volume, the type of compound it is made of, or the rim width. Likewise, aspects such as the rider's weight, their usual riding style, the type of terrain, or the weather conditions also influence the pressure at which bicycle tires should be inflated: higher, lower... We are going to explain how all these factors influence the choice of the ideal tire pressure. At the end of the post, we will show you a complete table where you can find the recommended pressures considering all these variables.
Two references for measuring tire pressure: PSI and BAR
Before analyzing each of the aspects that influence the pressure at which bicycle tires should be inflated, we must start by clarifying some measurement terms. Especially for those who are still confused when applying the correct pressure using a pressure gauge. On pumps with a pressure gauge, you will generally see guides in PSI (pounds per square inch) and bar. Both are units for measuring pressure, the first being more commonly used in English-speaking countries and the second more internationally. You can measure your tire pressure with either reference, although the PSI guide may be more convenient. This is because, for bicycle tires, most manufacturers usually indicate the recommended pressure in PSI. However, and especially in Spain, bar has become more widely used among most cyclists. The equivalence between both units is 1 bar = 14.5 psi.
1 bar = 14.5 psi
In this way, it is important to have, first and foremost, a floor pump with an integrated pressure gauge. This will allow us to calibrate the pressure of each tire in detail, discarding the imprecise method of checking by touch.
BAR/PSI equivalence table
| BAR | 0.5 | 1 | 1, | 2 | 2.5 | 3 | 3.5 | 4 | 4.5 | 5 |
| PSI | 7 | 15 | 22 | 19 | 36 | 44 | 51 | 58 | 65 | 73 |
| BAR | 5.5 | 6 | 6.5 | 7 | 7.5 | 8 | 8.5 | 9 | 9.5 | 10 |
| PSI | 80 | 87 | 94 | 102 | 109 | 116 | 123 | 131 | 138 | 145 |
Factors that influence tire pressure
Below we show you some relevant factors that influence determining the most appropriate pressure to which we should inflate the tires of our bicycle.
The size of the tire
The size of the tire, its diameter and width or balloon, largely determine the pressure it should have. In mountain bike, for example, possibly the discipline where tire pressure plays the most important role, a 27.5-inch diameter tire will have greater rolling resistance (the contact surface with the ground will be larger) than a 29” one. That’s why it will need to be inflated to a higher pressure. The same happens with a narrower tire. Taking again the measurements for mountain bike and referring to the manufacturers’ recommended pressure table, as a general rule, you should increase the pressure by 0.2 bar for every 0.2 inches the balloon is reduced. In road cycling, the width of the tires is usually expressed in millimeters. The rule is usually that for every 1 mm the width is reduced, the pressure should increase by 0.5 bar.
Thus, considering only the width of the tire, we can obtain a pressure measurement very close to our needs. Wider tires will always provide more grip and stability with less pressure. But at the same time, they will wear out faster than narrower ones, which will not be as stable and manageable as the former, but will be more agile and faster. Related to this, the internal width of the rim also matters. Just like the tire itself, a wider rim requires less pressure than a narrower one.
The material of the tire
Manufacturers offer within each tire model different versions depending on the type of compound used. The resistance of each is measured in TPI (threads per inch – threads per inch). The higher the TPI, the lighter and less durable the compound will be. A tire with higher TPI will require an increase in pressure. On the other hand, a lower TPI, that is, with fewer threads in the compound needed for its manufacture, will be more resistant to wear and, therefore, will require less pressure to achieve its ideal performance. On the other hand, the chosen puncture-proof solution also influences pressure variation. If you ride with tubeless tires, you can lower the pressure by 0.2 to 0.3 bars, obtaining the same or better performance, since you will reduce the moving weight of the wheels.
The position of the wheel (front or rear)
In addition, another mechanical factor to consider is the position of the tire, whether it is the front or the rear. It is advisable, and the main manufacturers in the sector (Michelin, Maxxis, Schwalbe or Continental) recommend that both wheels should not have the same pressure, indicating a 60-40 distribution for the rear and front tires, respectively. This is because the driving wheel, the rear, will need more pressure due to its greater rolling condition than the front. And the latter needs more grip and stability because it is primarily responsible for steering the bike, as well as absorbing much of the impact from obstacles and terrain irregularities.
The cyclist's weight
The cyclist's weight is one of the key factors, along with tire width, when choosing the ideal pressure. A heavier cyclist will need to put more pressure in their tires than a lighter one. The weight itself increases the surface or tread area of the tire and, therefore, reduces speed and increases wear. Each manufacturer recommends a certain pressure according to weight ranges. But, in general, and as an initial point of reference, for every 5 kg of extra weight, the pressure should be increased by 0.1 bars.
The type of terrain and the weather
The most specific tire pressure adjustments are determined by the type of terrain (smooth or uneven) and weather conditions. All of these are external factors that can change from one day to the next. That is why it is recommended that, starting from a reference pressure taken into account by the factors described above, you adjust more or less within certain margins depending on the type of terrain you are going to ride on and/or the weather. Thus, the smoother and firmer the terrain, the higher the pressure will be beneficial. While on rough, uneven, obstacle-filled, or slippery surfaces (wet, muddy, or sandy), it is advisable to lower it slightly to increase grip. On the other hand, although less important due to its reduced impact during the ride itself, a lower external temperature reduces tire pressure. Manufacturers disagree on how much it is reduced depending on the degrees, but approximately for every 10ºC less, the tire will lose 0.1 bar, because air tends to contract with cold.
Recommended tire pressure table for bicycle tires
Taking into account the most important factors when choosing the correct tire pressure, which are tire width and rider weight, we have created this general pressure table or guide. This time, we divide it into the two most common cycling disciplines, MTB and road, taking into account the ranges recommended by the main manufacturers.
Wheel pressure table for mountain bikes
| Rider weight (in kg) | Tire width (in inches) | ||||
| 1.9" - 2.1" | 2.2" - 2.3" | 2.4" - 2.5" | 2.6" - 3" (Plus) | 3.8" - 4.5" (Fatbike) | |
| 60 kg | 2 bar / 29 psi | 1.9 bar / 27 psi | 1.7 bar / 24 psi | 1.2 bar / 1.7 psi | 0.5 bar / 7 psi |
| 70 kg | 2.1 bar / 30 psi | 2 bar / 29 psi | 1.8 bar / 26 psi | 1.3 bar / 1.9 psi | 0.6 bar / 9 psi |
| 80 kg | 2.2 bar / 32 psi | 2.1 bar / 30 psi | 1.9 bar / 27 psi | 1.4 bar / 20 psi | 0.7 bar / 10 psi |
| 90 kg | 2.3 bar / 33 psi | 2.2 bar / 32 psi | 2 bar / 29 psi | 1.6 bar / 23 psi | 0.9 bar / 13 psi |
| 100 kg | 2.4 bar / 35 psi | 2.3 bar / 33 psi | 2.1 bar / 30 psi | 1.7 bar / 24 psi | 1 bar / 14 psi |
Road bike wheel pressure table
| Rider weight (in kg) | Tire width (in millimeters) | ||||
| 23 mm | 25 mm | 28 mm | 30 mm | 32 mm | |
| 50 kg | 6 bar / 87 psi | 5 bar / 72 psi | 4 bar / 58 psi | 3 bar / 43 psi | 2.6 bar / 38 psi |
| 60 kg | 6.7 bar / 97 psi | 5.6 bar / 81 psi | 4.6 bar / 67 psi | 3.5 bar / 51 psi | 2.9 bar / 42 psi |
| 70 kg | 7.3 bar / 106 psi | 6.3 bar / 91 psi | 5.3 bar / 77 psi | 4.1 bar / 59 psi | 3.2 bar / 46 psi |
| 80 kg | 7.8 bar / 113 psi | 6.9 bar / 100 psi | 6 bar / 87 psi | 4.8 bar / 69 psi | 3.5 bar / 51 psi |
| 90 kg | 8.3 bar / 120 psi | 7.4 bar / 107 psi | 6.5 bar / 94 psi | 5.4 bar / 78 psi | 3.9 bar / 56 psi |
Finally, if you want to adjust your tire pressure precisely, you can use a specific app. In the Google Play Store (for Android phones) or the App Store (for iPhone), you will find various options by searching for terms like "bike tire pressure." Also, many bicycle tire manufacturers offer tools and guides on their websites to calculate the optimal pressure according to tire width, compound type, and rider weight. Properly adjusting your wheel pressure not only improves performance and comfort while riding, but also prolongs tire life and optimizes traction on different terrains.