How to properly inflate a suspension fork

Why the right air pressure is important and how to set it for your bike

The suspension fork on your bike provides noticeably more comfort on uneven trails, low curbs, or cobblestones. To ensure it works properly, the correct air pressure is essential. If the pressure is too low, the fork compresses too quickly and loses its effect – if it’s too high, the fork becomes too stiff and barely gives way. So air pressure directly affects how comfortable and safe your bike is to ride.

What you need to inflate it:

To adjust the air pressure, you'll need a shock pump. It is specifically designed for air suspension systems and features a precise pressure gauge that allows you to adjust the pressure with precision. Standard bicycle pumps aren't suitable for this – they don't provide the necessary precision.

How do I know how much air pressure the fork needs?

Every suspension fork has specific guidelines regarding how much air it should be filled with. You can find this information either: 

directly as a sticker on the fork,
in the user manual included with your bike, or
on the fork manufacturer's website.

The guidelines are usually based on body weight – including clothing, a backpack, or a shopping bag. A common value is 1 bar per 10 kg of body weight, but this may vary slightly depending on the type of fork.

Here's how to properly inflate your suspension fork:

Have the shock pump ready 
To inflate the fork, you'll need a special shock pump with a pressure gauge. Conventional bicycle pumps aren't suitable because they aren't precise enough.
Expose the valve 
Unscrew the dust cap from the air valve. It is usually a Schrader valve located at the top of the fork.
Connect the pump and check the pressure 
Screw the shock pump onto the valve so that it is airtight. Now you can check the current air pressure and adjust it as needed, based on the manufacturer's recommendations.
Adjust the pressure and check the sag
If you'd like, you can take the so-called sag test. To do this, sit down gently on the bike, apply a little pressure, and see how far the fork compresses.
For everyday use on a city bike, about 25 to 30% of the total travel is a good guideline. Some forks have a rubber ring for guidance.
Remove the pump again and screw the cap back on 
Turn the pump off slowly – the hissing sound is normal and comes only from the pump, not from the fork. Then replace the valve cap.

Good to know:

You don't have to pump the fork often. Once the pressure is set correctly, it usually remains stable for several weeks. A quick check is only necessary if you notice a change in bike handling or after it has been parked for a longer time.