29er Tire Pressure – A Guide To All Conditions


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Getting the tire pressure right for 29ers is no mean feat.

Riding with tires that are pumped up too much can lead to blowouts, and makes the riding conditions harsher. On the flip side, tires that are underinflated can get pinch punctures.

Therefore, getting the tire pressure right is very important.

For wet conditions, and for trails/mountain biking, the PSI range for 29ers should be between 14.7 PSI and 22.8 PSI, and for dry conditions between 16.4 PSI and 25.4 PSI. However, never go above the recommended PSI stated on the tire.

In general, you want to use a pump that tells you the tire pressure as you’re pumping. That way you won’t be guessing. However, based on your weight, and the conditions of the ground you’re riding on you should adjust the pressure of all bicycle tires, including 29ers. 

So, below I will provide a full guide for what to change the tire pressure of 29ers to based on different factors such as your body weight, the type of riding you’re doing, and the conditions of the ground you’re riding on. 

29er bike tire pressure

How To Adjust the Tire Pressure of 29ers For All Conditions

In regions that have 4 seasons, the temperature will drop in winter, and increase in summer, and the change in temperature affects the PSI of tires. Also, in wet weather, it’s better to have your tires at a lower PSI. 

So, below I will explain a reasonable PSI range to have your 29’er tires at based on wet conditions, dry conditions, how heavy you are, and the air temperature.

Overall, set the tire pressure to the minimum tire pressure stated on the tire, and test how it feels to ride. Then increase it gradually and see how it feels. Don’t go above the maximum pressure. In winter reduce the PSI by about 1.3 compared to summer, as it will provide a better grip.

For wet conditions, and for riding on the ROAD the PSI range for 29ers should be between 18.1 PSI and 28.1 PSI.

The PSI changes based on how heavy you/the rider is.

For example, if you’re a heavier individual you should pump your tires closer to the higher end of the range. However, if you’re much lighter then you should have them pumped up to the PSI on the lower end of the range.

To be more precise about the tire pressure that 29ers should aim for, I’ve compiled 4 tables below showing how pumped up they should be. The 4 tables cover:

  • A mountain/trail bike – wet conditions
  • A mountain/trail bike – dry conditions
  • A road bike – wet conditions
  • A road bike – dry conditions

Here are the 4 tables with the PSI ranges for the front and rear tires and based on how heavy you or the rider is:

29er Tire Pressure PSI – Mountain/trail bike – wet conditions

Weight of rider (lbs)Weight of rider (kg)Front tireRear tire
110 lbs50 kg14.7 PSI15.7 PSI
121 lbs55 kg15.2 PSI16.1 PSI
132 lbs60 kg15.6 PSI16.6 PSI
143 lbs65 kg16.1 PSI17.1 PSI
154 lbs70 kg16.5 PSI17.6 PSI
165 lbs75 kg17.0 PSI18.1 PSI
176 lbs80 kg17.4 PSI18.5 PSI
187 lbs85 kg17.9 PSI19.0 PSI
198 lbs90 kg18.3 PSI19.5 PSI
209 lbs95 kg18.8 PSI20.0 PSI
220 lbs100 kg19.2 PSI20.5 PSI
231 lbs105 kg19.7 PSI20.9 PSI
242 lbs110 kg20.1 PSI21.4 PSI
253 lbs115 kg20.6 PSI21.9 PSI
264 lbs120 kg21.0 PSI22.4 PSI
275 lbs125 kg21.5 PSI22.9 PSI

29er Tire Pressure PSI – Mountain/trail bike – dry conditions

Weight of rider (lbs)Weight of rider (kg)Front tireRear tire
110 lbs50 kg16.4 PSI17.4 PSI
121 lbs55 kg16.9 PSI17.9 PSI
132 lbs60 kg17.4 PSI18.5 PSI
143 lbs65 kg17.9 PSI19.0 PSI
154 lbs70 kg18.4 PSI19.5 PSI
165 lbs75 kg18.9 PSI20.1 PSI
176 lbs80 kg19.4 PSI20.6 PSI
187 lbs85 kg19.9 PSI21.1 PSI
198 lbs90 kg20.4 PSI21.7 PSI
209 lbs95 kg20.9 PSI22.2 PSI
220 lbs100 kg21.4 PSI22.7 PSI
231 lbs105 kg21.9 PSI23.3 PSI
242 lbs110 kg22.4 PSI23.8 PSI
253 lbs115 kg22.9 PSI24.3 PSI
264 lbs120 kg23.4 PSI24.9 PSI
275 lbs125 kg23.9 PSI25.4 PSI

29er Tire Pressure PSI – Road bike – wet conditions

Weight of rider (lbs)Weight of rider (kg)Front tireRear tire
110 lbs50 kg18.1 PSI19.3 PSI
121 lbs55 kg18.7 PSI19.9 PSI
132 lbs60 kg19.2 PSI20.5 PSI
143 lbs65 kg19.8 PSI21.1 PSI
154 lbs70 kg20.3 PSI21.6 PSI
165 lbs75 kg20.9 PSI22.2 PSI
176 lbs80 kg21.5 PSI22.8 PSI
187 lbs85 kg22.0 PSI23.4 PSI
198 lbs90 kg22.6 PSI24.0 PSI
209 lbs95 kg23.1 PSI24.6 PSI
220 lbs100 kg23.7 PSI25.2 PSI
231 lbs105 kg24.2 PSI25.8 PSI
242 lbs110 kg24.8 PSI26.4 PSI
253 lbs115 kg25.3 PSI27.0 PSI
264 lbs120 kg25.9 PSI27.6 PSI
275 lbs125 kg26.5 PSI28.1 PSI

29er Tire Pressure PSI – Road bike – dry conditions

Weight of rider (lbs)Weight of rider (kg)Front tireRear tire
110 lbs50 kg20.1 PSI21.4 PSI
121 lbs55 kg20.8 PSI22.1 PSI
132 lbs60 kg21.4 PSI22.7 PSI
143 lbs65 kg22.0 PSI23.4 PSI
154 lbs70 kg22.6 PSI24.0 PSI
165 lbs75 kg23.2 PSI24.7 PSI
176 lbs80 kg23.8 PSI25.4 PSI
187 lbs85 kg24.5 PSI26.0 PSI
198 lbs90 kg25.1 PSI26.7 PSI
209 lbs95 kg25.7 PSI27.3 PSI
220 lbs100 kg26.3 PSI28.0 PSI
231 lbs105 kg26.9 PSI28.6 PSI
242 lbs110 kg27.5 PSI29.3 PSI
253 lbs115 kg28.2 PSI30.0 PSI
264 lbs120 kg28.8 PSI30.6 PSI
275 lbs125 kg29.4 PSI31.3 PSI

*Note that recommended tire pressures are a guide only. The exact pressure should never exceed that stated on the tire. There are also multiple different tire constructions that alter the PSI that the tire should be.

There are a few different types of casing used in 29er tires. These are:

  • Standard
  • Reinforced
  • DH casing/Double-ply

As well as different rim types such as:

  • Tubes (crochet)
  • Tubular
  • Hooks (Tubeless crochet)
  • Hooks (Tubeless straight side)

The exact PSI does vary slightly based on these factors as well. These different factors are generally printed on the tire. But, can also be listed in the product description.

For the exact tire pressure based on the casing, and rim type refer to this tool by the cycling company SRAM.

When using the tool note that 29ers are also called 700C tires. So, use this for the wheel diameter option.

29er tire pressure
The exact psi required for a particular 29er tire is influenced by a range of factors, including conditions, rider weight, tire materials, and more…

Why the PSI is lower for wet conditions and for a trail/mountain bike

The PSI that you should pump your 29er tires to varies for wet and dry conditions, and for trail/mountain biking and road riding because the surface is harder or softer. When the surface is harder such as a road, the tire pressure should be more. 

This is because you don’t need the extra grip provided by tires that aren’t pumped to as high a PSI. Tires that are a lower PSI have more ‘give’ in them. Meaning they absorb the changes in the surface underneath more. This gives them more traction, so the tires are less likely to skid out.

29’ers are used most commonly on mountain bikes and hybrid bikes. As, you may know, hybrid bikes can be used well on the road and for mountain bike style riding. Whereas, a traditional mountain bike/trail bike is ideally suited to riding offroad, and not as good for riding on the road.

How the air temperature affects the PSI of 29ers should be

The air pressure listed above refers to temperate conditions. When the temperature drops or increases. The PSI that your tires are will increase and decrease ever so slightly. A general rule of thumb is that for every 10 degrees Fahrenheit that the temperature increases or decreases, the tire pressure will increase or decrease by 2%.

As you may remember, from high school chemistry class when the temperature increases it increases the kinetic energy.

This is what causes water to turn to steam. The molecules bounce around so fast that some escape to the air as they turn from a liquid into a gas. So, when the temperature increases the tire pressure increases.

The increase and decrease are not very large, and would only amount to about a 10% increase or decrease in the PSI for large temperature changes

Therefore, when the temperature changes quite a lot, it’s best to pump them to a PSI recommended in the tables above and then adjust it slightly up or down based on what feels better, and as previously mentioned don’t go above the PSI printed on your tires

Here’s a table that shows how the PSI would change based on the temperature:

Temperature (°F)Temperature (°C)Recommended PSI
47 °F8 °C22.8 PSI
57 °F14 °C22.4 PSI
67 °F19 °C21.9 PSI
77 °F25 °C21.5 PSI
87 °F30 °C21.1 PSI
97 °F36 °C20.6 PSI
107 °F41 °C20.2 PSI

From the table, you can see that when the average temperate temperature of say around 70 °F goes down to the point where it feels cold, for example in the wintertime. The PSI of your tires will only go down 1.3 PSI. 

The same is true when it gets extremely hot in the summertime. Except the PSI goes up 1.3 PSI. Therefore, it isn’t a major factor but is something to be aware of because it will be slightly noticeable.

There are also different tire widths that are used for different types of cycling (source).

The reason is that fatter tires are:

  • Not as responsive
  • Provide additional drag

But, have the advantages of:

  • Have better traction
  • Are better at absorbing impacts

Should You Inflate Bike Tires to the Max PSI

There is a PSI range stated on bike tires, a minimum, and a maximum. You can inflate bike tires based on how they feel provided you don’t ride your bike outside this range. But, here’s whether you should inflate bike tires to the maximum PSI.

As a general rule, do not inflate bike tires to the maximum PSI. The maximum PSI makes the ride feel harsher. Start by inflating the tires to the minimum PSI on the tire. Then slightly increase it until it feels comfortable for you. But, never exceed the maximum PSI stated on the tire.

Bike tires that are inflated to the max don’t absorb as much of the bumps. This means every small bump goes through the bike and makes the ride overall less comfortable. 

Therefore, it’s generally not best to pump bike tires to the maximum PSI. It is more of a provided as a guide so that the tire is accidentally pumped up so high that it bursts.

Sources

Martin Williams

Martin has been tearing up all sorts of trails on a range of bikes ever since he was young. He once cycled across France, and once fell into a canal on a hybrid. He writes about everything to do with cycling on our site. You can find out more about him at bicycle2work.com/about-martin-williams/

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