Kids Bike Tire Pressure – The Complete Guide


This post may contain affiliate links. If you click an affiliate link and make a purchase, I may earn a commission. Also, as an Amazon Associate, I earn from qualifying purchases.
--

Kid’s bikes are a bit different from adult bikes.

They come in a more diverse range of heights, and tire sizes. The bike frame itself is also heavier, though children are much lighter than adults.

All of these factors mean that the pressure of kid’s tires is much different from adults’ tires so in this article I will explain everything there is to know about the pressure of kid’s bike tires.

Overall, kid’s bike pressure range from 7.6 PSI for to 2 to 4-year-olds, to about 11.5 PSI for 10-year-olds. The pressure of kid’s tires should also be lower by about 2 PSI for kid’s bikes used on uneven or wet ground.

Below, I will provide some tables that show some PSI ranges for kid’s bikes based on the conditions that the bike will be ridden in and the age of the kid.

Kids bike tire pressure

The diameter and height of the tire affects the tire pressure

Kid’s bikes come in a range of sizes. Older kids need a bigger bike, whereas, smaller kids will have a bike that suits their height. The bigger bike frame needs bigger wheels. Therefore, there are a few different sizes of tires for kids. 

The size of the tire is approximately matched to a child’s age. However, of course, some kids are taller than others for their age, or they might have longer legs which makes a bigger bike frame the right height for them.

Here’s a table that shows what wheel size goes with what bike frame, and about what age each tire size corresponds to.

Wheel SizeAgeInseamHeight
14″2 – 4 years15″ – 20″37 – 44″
16″4 – 6 years16″ – 22″41 – 48″
20″5 – 8 years19″ – 25″45 – 54″
24″8 – 11 years23″ – 28″49″ – 59″
26″10 + years25″ +56″ +

(source)

The width of tires for kid’s bikes ranges from between 1.5 to 2.5 inches (3.81 cm to 6.35 cm). Each wheel size requires a different pressure.

As you may know, tire pressure is measured in pounds per square inch (PSI), and bars. 

The pressure of tires can be estimated by squeezing them, and also seeing how much they sag when the rider is sitting on it.

But, in general, it’s a good idea to be as precise as possible.

To do that you will need a pressure gauge. Some hand pumps have a built-in PSI gauge. These can be digital or mechanical.

That way once the tires get close to the recommended PSI, you can begin testing it until it’s about right. It’s also important to note that the conditions change what the PSI of tires should be. 

The two main types are if the bike is going to be ridden mostly on pavement and the road OR if it’s going to be ridden mostly off-road such as mountain biking, and downhill riding.

The surface of the pavement or road is much harder and therefore, the PSI, in general, should be higher. In off-road conditions such as mountain biking, a lower PSI is better.

The reason is the tires will absorb more of the minor bumps on the riding surface such as dirt, or rocks.

Kids bike tire pressure
Kid bike tire pressure ranges from 7.6psi to 11.5psi depending on a range of factors

How to find the diameter of the tires on your kid’s bike

On the tires of your kid’s bikes will be a few numbers. They can be embossed on the bike tire or written using a special kind of paint. 

The number which will tell you what the diameter of the tires are typically the first number followed by another number. 

Such as 24 x 1.75. The 24 is the diameter of the tire in inches. So, in this case, it will be a 24-inch tire, and the second number is the width of the tire in inches.

In this example is 1.75 inches or 44 mm. It can also have the mm format and be written as something like 660 x 50c. 

The format is the same – the first number is the diameter of the tire and the second number is the width of the tire. The difference is that it’s written in millimeters (mm) rather than in inches.

The maximum and minimum PSI can be written or embossed on the tire

The PSI of a tire does need to be adjusted based on the weight of the child riding it, and the conditions where the bike will be written.

However, on many tires, the maximum and minimum PSI will be embossed or printed on the rim of the tire. It will say something like MIN 20 – MAX 25 P.S.I., which in this example means a minimum of 20 PSI, and a maximum of 25 PSI.

Here’s a really good video that shows what the maximum PSI and diameter of the tires on your bike look like:

Here are the tables that show how the PSI is different based on the conditions (wet or dry), and the surface that the tires are ridden on (off-road or pavement/road):

14-inch wheels (2 to 4 year old kids)

Off road/mountain biking (wet conditions):

Front tireRear tire
7.6 to 13.09.0 to 14.7

Off road/mountain biking (dry conditions):

Front tireRear tire
9.6 to 11.011.0 to 12.7

Road/pavement (wet conditions):

Front tireRear tire
10.6 to 13.412.0 to 14.3

Road/pavement (dry conditions):

Front tireRear tire
Up to 11.4Up to 12.3

16-inch wheels (4 to 6-year-old kids)

Off road/mountain biking (wet conditions):

Front tireRear tire
13.014.7

Off road/mountain biking (dry conditions):

Front tireRear tire
11.012.7

Road/pavement (wet conditions):

Front tireRear tire
13.414.3

Road/pavement (dry conditions):

Front tireRear tire
11.412.3

20-inch wheels (5 to 8 year old kids)

Off road/mountain biking (wet conditions):

Front tireRear tire
15.016.9

Off road/mountain biking (dry conditions):

Front tireRear tire
13.014.9

Road/pavement (wet conditions):

Front tireRear tire
15.416.5

Road/pavement (dry conditions):

Front tireRear tire
13.414.5

24-inch wheels (8 to 11 year old kids)

Off road/mountain biking (wet conditions):

Front tireRear tire
11.2 to 15.012.6 to 16.9

Off road/mountain biking (dry conditions):

Front tireRear tire
9.2 to 13.010.6 to 14.9

Road/pavement (wet conditions):

Front tireRear tire
11.5 to 15.412.3 to 16.5

Road/pavement (dry conditions):

Front tireRear tire
9.5 to 13.410.3 to 14.5

26-inch wheels (8 to 11 year old kids)

Off road/mountain biking (wet conditions):

Front tireRear tire
11.212.6

Off road/mountain biking (dry conditions):

Front tireRear tire
9.210.6

Road/pavement (wet conditions):

Front tireRear tire
11.512.3

Road/pavement (dry conditions):

Front tireRear tire
9.510.3

What happens when bike tires are pumped up too high

In general, you wouldn’t want to purposefully pump up bike tires far more than what’s recommended.

Also, before explaining the advantages it’s not recommended to pump bike tires up past the maximum PSI. If a tire pops when riding it, it can cause a serious accident.

However, here’s what happens if bike tires are pumped up close to the maximum PSI and even over. 

  • Have less grip
  • Are more responsive
  • Aren’t as comfortable on uneven ground/road/pavement
  • Can burst when being pumped up

Bike tires that are much higher pressure have less cushion in them. The extra cushion provided by tires that aren’t pumped up really high absorbs turns, and minor changes in the underlying surface that the bike is riding on.

Overall, this gives them less grip.

Tires that aren’t pumped up as high have a bit of lag between when you pedal and when the tire responds.

Whereas, hard tires respond virtually instantly to any acceleration or deceleration.

This makes them more responsive which also makes them easier to control. Giving you more precision when you ride.

However, going past the recommended maximum PSI can cause them to burst. Here’s a video of an experiment one guy did to see if bike tires burst when pumped up too high:

And here’s another video where a guy sees how high a tire can be pumped using a hand pump. Note: eventually he does get the tire to burst when pumping it up by hand:

What happens when bike tires aren’t pumped up enough

On the other hand, when bike tires are pumped up close to the bottom of the recommended pressure range it’s pretty much the opposite of when bike tires are pumped up to really high PSIs. They are:

  • Not as responsive
  • More comfortable on uneven ground
  • Have more grip
  • If too low they can develop ‘snake bite’ punctures

Tires that aren’t pumped up to the middle of the recommended PSI range, and are closer to the lower end of the recommended PSI range absorb the bumps in the surface more. This makes them more comfortable.

However, when you pedal or brake there is a slight delay that makes them overall less responsive than tires that are pumped to a higher PSI.

If the tires sag too much they can develop what are called snake bite punctures.

This is where the inner tube is cut by the rim of the tire. When the pressure of the tire is too low and you hit an obstacle like a curb or a large branch or log and the tire is pressed hard against the rims.

How Do You Pump Up a Kids Bike Tire?

New bike tires don’t come already pumped up unless you buy a whole bike. New bike tires that are already pumped also need to be checked to see if they are the right PSI, and can require a bit of pumping. So, here’s a summary of how to pump up a kid’s bike tires.

As a general rule, use a hand pump. Care needs to be taken not to pump them up too high as they can burst. The maximum PSI is almost always printed or embossed on the sidewalls of the tire. You need an air pressure gauge to know precisely how pumped up the tires are.

Generally, you can tell if they are pumped up enough by having the child sit on the bike.

However, you need to be careful to have them pumped up enough that when the child sits on the bike the tires don’t sag very much at all. This can cause what are called snake bike punctures.

Especially if the bike is ridden when the tires sag a lot. The tires should not sag more than halfway from the rim to the ground when the person who’s going to ride it is sitting on it.

Kid holding his bicycle tire
Using a simple hand pump and a pressure gauge is the easiest way of keeping kids’ tires at a good air pressure

What PSI Should a Child’s Bike Be?

The pressure of bike tires affects how well they ride, improves the grip, and stops them from developing PSI-related punctures.

Children’s bike tires, especially young children’s bike tires are much smaller in size than adult tires. So, here’s an explanation about what PSI children’s bike tires should be.

Overall, between 7.6 PSI and 14.9 PSI. Children’s bike tires range in diameter from 12 inches for 2 to 4 year old to 26 inches for 8 to 11-year-olds. In general, large tires need more pressure than smaller tires. The minimum and maximum PSI are embossed or printed on the rim of the tire.

It’s very important to not pump your kid’s bike tires over the recommended PSI that is embossed or printed on the tire.

Or, to ride them when they’re not pumped up above the minimum pressure printed on the tire. It can lead to the bike tire developing a puncture.

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/

Recent Posts