ASK THE MXPERTS: WP AER AIR FORK PRESSURE ON A 2017-1/2 FACTORY EDITION

Dear MXA,

Do you have any articles on your website that will give me an idea of what air pressure I should be running in my 2017-1/2 KTM 450SXF Factory Edition? It has the WP AER 48 forks. Thanks!

There are those who say that all we have on our website is articles about what pressure to run in WP AER forks. You should Google “MXA 2018 KTM 450SXF test” to get advice for your Factory Edition. The trick to getting the most from your AER air forks is to find the proper air pressure for your weight, speed and track.

We typically start with the OEM-recommended air pressure and then lower it in 2-psi increments. How do we know when we have the proper pressure? We lower the air pressure to the point where the forks are almost getting full travel. We don’t want them to bottom completely, but we also don’t want them to feel like they are dropping into their stroke.

Typically, the AER forks ride high in their stroke with the stock air pressure. Slower or lighter riders might have to lower the oil height in the damping leg by 10cc or more to get full travel. Additionally, the air pressure goes up as the ambient temperature rises. In these cases, just reset the air pressure to your chosen setting between motos. It should be noted that if you ride long motos, the air pressure will rise by 4 psi because of internal friction. We bleed the outer chambers regularly.

Don’t be afraid to go down on the air pressure just because the manual says to run 156 psi. We use a zip-tie on the fork leg to see how much travel we are getting. Then, we raise or lower the air pressure until we have 1.5 inches of travel left on the zip-tie. We have riders who run as low as 135 psi. Once you find the right air pressure for you, use the compression clicker to dial in the feel. Set the air pressure in the WP AER forks first and then tune with the clickers.

For hardcore racing, we recommend this fork setup for your 2017-1/2 KTM 450SXF Factory Edition, which is an early-model release of the 2018 model:

2017-1/2 KTM 450SXF FACTORY EDITION FORK SETTINGS
Spring rate: 135 psi (Novice), 145 psi (Intermediate), 150 psi (Expert)
Compression: 15 clicks out
Rebound: 15 clicks out
Fork-leg height: Third line