I see other riders diligently checking their mountain bikes tire pressure and dialing in the perfect pressure for them before almost every ride I go on. I didn’t want to be the only one left out, and I want the best performance, so I researched what the best tire pressure for a mountain bike is. Here is what I discovered…
What is The Correct Mountain Bike Tire Pressure?
For tubed MTB tires a great pressure is 30 psi on the front tire and 33 psi on the rear. For tubeless mountain bike tires 22 psi on the front and 24 psi on the rear tire. But there are many factors that go into optimal tire pressure and you should have fun and experiment to find the best pressure for you.
Results From My MTB Tire Pressure Poll
I asked the 29,600 mountain bikers in two Facebook Groups what they recommend as a good starting point for the average rider.
Wow, the results of this poll were amazing, I received 178 comments and broke down the data into the average and most common tire pressures.
For Tubed MTB Tires
|Front Tire||Rear Tire|
|Average = 30.6 psi||Average = 33.9 psi|
|Most Common = 30 psi||Most Common = 30 psi|
For Tubeless Tires
|Front Tire||Rear Tire|
|Average = 22.6 psi||Average = 25.1 psi|
|Most Common = 22 psi||Most Common = 24 psi|
What really came out of the poll is the variety of factors that go into setting the pressure on your MTB bike tires. I’ve tried to tackle each of these in the rest of this article plus I’ve included an experiment for finding the best MTB tire pressure for you.
Problems Associated with Improper Mountain Bike Tire Pressure
Tire Pressure Too Low
If your mountain bike’s tire pressure is too low then a myriad of rim and tire damages can occur. One such problem that can occur are pinch cuts, also known as a “snake bite”. Pinch cuts are the result of hitting an angled surface like a rock or a pothole. Hitting a sharp edge causes a tire with low pressure to pinch the inner tube between the edge and the rim of the bike.
Another problem that running low pressures can cause is burping. Burping, in contrast to the previously mentioned problem, is associated with only tubeless tires. Burping occurs when the seal of the tubeless tire and the rim of the tire is temporarily broken by a hard landing or cornering. This results in a slight loss of tire pressure, although because the tire pressure was already low this could eventually lead to rim damage.
Rim damage is probably the most common issue with running lower than optimal tire pressure. Simply put, if the pressure of the tire is not high enough to absorb the weight of the rider and the impact of the terrain then the tire will bottom out and the rim will be taking the impact. This can cause the rim to bend or simply flatten out at one point. In either case this is usually the end of that rims life and will need to be replaced before the bike can be ridden again.
Tire Pressure Too High
Although it is less common, having a high mountain bike tire pressure can also cause terrible problems for the rider. The most common of which is blowouts. Blowouts are characterized by a sudden loud bang followed by the immediate loss of most of the pressure of the tire. This is caused by a compression of the tire by an impact, coupled with an already high tire pressure. The pressure, simply, becomes too high for the tubed or tubeless tire to withstand and so in tubed tires the inner tube tears and in the case of tubeless tires the seal is completely gone and all pressure is released.
Another problem that goes along with too high of a mountain bike tire pressure is that of low traction and a loss of comfortability in riding. Especially when riding on loose terrain, a lower pressure will allow the tire to conform to the ground beneath it creating more traction. Additionally, when the tire pressure is too high then the tire will become rigid and not conform to any sort of rough terrain, this will cause an unnecessarily uncomfortable ride.
Factors Which Affect the Perfect Mountain Bike Tire Pressure
Rider Weight a BIG Factor in MTB Tire Pressure
The recommended tire pressures above were mad with an average rider weight of 160 lbs in weight. However, since a higher rider weight will compress the tire more, or a lower rider weight will compress the tire lower, I would recommend for every 10 lb’s in difference adding or removing 1 psi. Considering the tire manufacturers minimum and maximum recommendations of course.
How MTB Tire Size / Tire Type Affect Pressure
Wider tires have higher volumes of air which results in their needing less pressure than narrower tires. This same principle holds true with wider diameter tires. A 26-inch tire will need a higher pressure than that of a 29-inch tire. Two simple rules can help you dial in the proper adjustments for each…
- For every 0.2-inch increase in thickness decrease pressure by 3 psi
- For every 2-inch increase in tire diameter decrease pressure by 2 psi
The type of tire, and material of said tire, also impacts the minimum and maximum psi that you should be running. Some higher end mountain bike tires have higher tpi, or threads per inch, this means that the material itself is denser and therefore is much stronger. In this case it is safe to run at lower pressures if that is necessary for the kind of riding you will be doing.
Moreover, some road bike tires or smooth mountain bike tires will have manufacturer recommendations near 65 or even 70 psi. this is because of their narrow stature and need for a very low rolling resistance. In this case it is best to consult the tire manufactures recommendation over everything else.
Surface Conditions That You Mountain Bike On
The conditions of the terrain which you’re riding on can also impact what pressure you might want to run your mountain bikes tires at. Whether it be for traction or decreased rolling resistance, tire pressure can vast improve the performance of your mountain bike. There is going to be a big difference in the need for a bike with good traction when riding on say sand vs asphalt for example.
In regard to traction, generally, a lower tire pressure means more traction. This is because the tire is able to mold to the ground beneath it and grab onto any uneven terrain. Higher tire pressures, conversely, become rigid and instead roll over any malformations in the trail, depositing all of the impact into the suspension of the mountain bike and the rider themselves.
In reference to rolling resistance the same rule holds true. As tire pressure decreases rolling resistance increases, meaning that the bike will roll slower at lower pressures. At higher pressures, conversely, the bike will roll faster. This is because of the effect that pressure has on traction. Higher traction means more friction which results in more rolling resistance.
MTB Front Tire vs Rear Tire Pressure
The front tire can be inflated to a lower tire pressure than that of the rear tire because of the way that weight is distributed on mountain bikes. In the case of both impact absorption and simply weight absorption the rear tire takes most of the force. Therefore, the rear tire needs a higher pressure to maintain proper function as compared to the front tire which does not need this added pressure.
Although, if traction is not an absolute need for the trail you will be riding on then the safest configuration is a higher psi in the front as well. Running both the front and rear tire at the same higher psi will not impact the feel of the bike in any significant manner unless there is a lot of loose ground or uphill riding that will be done.
There is also the consideration type of suspension which is featured on your mountain bike. On a bike that has a front fork with a large amount of travel, the tire can theoretically be inflated to a lower psi if the rider so chooses to do so. The same goes for a bike which is full-suspension, instead of a hardtail, in reference to the pressure of the rear tire. A mountain bike outfitted with a rear suspension system can have a rear tire with lower pressure.
Does Air Temperature Affect MTB Tire Pressure?
Temperature affects the density of air in all tires but, specifically, in regard to mountain bike tires every 10 degrees Fahrenheit of change will result in either a 2% increase or decrease in tire pressure. Meaning that if you inflate your mountain bike’s tires inside then for every 10 degrees that the temperature is different outside the pressure inside the tire will, over time, increase or decrease 2%. Increasing when the temperature outside is higher than where you inflated the mountain bikes tires and lower when it is colder.
It is for this reason that, unless you want to do a bunch of math to figure out exactly how much air to put in the tires to get the perfect psi after the temperature change, I would recommend always inflating your tires in the same environment as you will be riding in. Having a portable air pump can help really help with this although since it can take a while to inflate with these pumps, I recommend inflating the tire to around the psi you desire and the adjusting with the portable pump at the location.
All of this is because with any added suspension the impact that will be absorbed by the tires will decrease. Although, again, just because your bike has good suspension that does not mean that you can run pressures lower than the manufacturers recommended minimum. This is because often the minimum is for extremely light riders and the manufacturers assume some sort of suspension on the bikes which will be using their tires. This is evident, clearly, by the recommendations on the tires which come with your mountain bike to begin with.
Mountain Bike Pressure Safety Tips
- If you are a heavier rider then it is much safer to get a tire with a higher tpi and, in turn, a higher maximum pressure rating than to exceed the manufacturers listed rating and risk a blowout.
- I already mentioned this, but, it is important to inflate your mountain bikes tire in an environment which is the same temperature as that of the environment where you’re going to be riding the mountain bike. That way the tire does not become dangerously under or over inflated for the conditions f the trial and the
- Never go outside of the recommended range of pressure by your mountain bike tire’s manufacturer.
- Always inspect your mountain bike’s tires for any punctures or malformations before inflating them. Do the same for the rims of your mountain bike as well.
- Adjust tire pressure throughout the day if the temperature or elevation of where the environment increases or decreases in a noticeable amount.
Mountain Bike Tire Pressure Gauges
One thing to remember, which can completely throw off all other considerations made in this article, is that not all tire pressure gauges are made to the same standard. While it is, admittedly, very tempting to buy a cheap tire pressure gauge; this is not a good idea. The best thing to do is to get a moderately priced tire pressure gauge that you trust and them always use only this gauge. That way the readings should be consistent.
Pro riders are super protective about their tire pressure gauge. I would Highly Recommend getting the Topeak D2 Smartgauge (link to Amazon) You can read more about this gauge here: Topeak D2 Smartgauge Review (links to my topeak D2 Smartgauge Review)
Using different gauges can cause your tires actual pressure to be off between inflations. This is not really a problem if you are just casually riding your mountain bike every once in a while, but, this is not the case for more regular use. Especially if you run at relatively low or relatively high pressures, this could cause problems which I detailed above.
Mountain Bike Tire Pressure Test
Now, I admit this all may be confusing to the beginning rider. This is why I have created this simple tire pressure test to help put these recommendations into action on your mountain bike.
If properly completed this test should provide any rider with a great set of pressures for both the rear and front tires of their mountain bike which can be used in almost any circumstance.
- Find a small trial or path which represents the kinds of terrain that you will most likely be riding on.
- Inflate the rear tire to the manufacturers maximum pressure recommendation. This will most likely be about 35 psi. Inflate the front to 5 psi below this maximum.
- Ride the trial once to get the tires warmed up and then do one more pass, this time recording your time and taking note of how comfortable the ride was.
- Now, let out 2 psi from each tire and then take another pass on the trail, again, noting your time and level of comfortability. Do this until you get down to the manufacturers recommended minimum on the front tire.
- Take these numbers and make your decision based up what time was the fastest and which one felt the most comfortable to you. This might be the same pressure but if not this will leave you making a compromise that is up to your discretion.
- Once you have these pressures, have a friend look at your tires while you are on the bike. There should be a slight bulge but not one which indicates the tire is flat. This will help prevent and pinch cuts or rim damage. To fix a flatter looking tire simply increase the tire by a few psi.
Does Riding Style Affect Proper Tire Pressure?
The short answer is… yes. The reason for this is that an aggressive rider will not be able to get away with the same low pressures than a more moderate rider will be able to. Furthermore, a downhill rider might want to increase tire pressure in the front to make it safer for drops.
Aggressive riders will suffer much greater impact and have a much higher possibility of rolling the tire while cornering. This is simply because an aggressive rider will run the bike at higher speeds and brake less in corners. Additionally, they are less likely to try and avoid rocks or other things which can cause pinch cuts. It is for this reason that they need higher pressures in both the rear ad front tire to maintain a safe riding experience.
Downhill riders, in particular, face similar difficulties. However, they do have the added caveat that they might want to run the front tire at the same high pressure as the rear tire. This is because in drops where the front tire hits the ground first, whether on purpose or by accident, there will be less of a chance of bottoming out and damaging the tube of the tire or the rim of the mountain bike itself.
Moreover, XC riders might want both tires to have as little rolling resistance as possible and have less of a consideration to traction. This of course depending on the terrain of the trial. However, they might want to do this mainly because the bike will roll farther on less power which in a long race can help the rider maintain their energy throughout.
Other Info on MTB Tires
I wrote an article about the different size tires you can put on MTB rims in this article: Can I Put Wider Tires On My Mountain Bike?
I’ve used a bunch of different Tires Pressure Gauge. Read this article about which one I consider the best: The Best Mountain Bike Tire Pressure Gauge and Review
As I researched this article I came across this article. Stans No Tubes is an icon in the “tire pressure business”. https://www.notubes.com/news/tire-pressure-how-to-find-the-perfect-tire-pressure/