Factory Connection AER48 Spring Kit


FC Install Only


The AER48 forks are separate function. The left side is the air side, the right side is the damping. The damping fork has the external clickers for compression and rebound adjustment. It has pistons and shims internally creating the damping forces necessary to control the action. So the AER48 forks do require Revalving and clicker adjustments to get them properly set up for the riders specific needs.

 AER48 Spring Kit

The AER48 air side fork has a sealed cartridge inside it; the internal cartridge is pressurized to create the spring effect. The air pressure is set on the top of the left fork. As air is compressed the pressure increases. In a fork as the air pressure increases it is essentially the same as going up on spring rate. In the AER48 fork to try and create the same effect as a spring you have a negative chamber air pressure. The negative chamber pressure decreases as the fork compresses creating a negative force. The AER48 fork is combining these two pressures to try and create the same effect as a straight rate spring.

At Factory Connection we have spent countless hours testing with the AER48 forks. We also field calls daily from riders trying to address the air aspect to the fork both in performance and maintenance. Based on our test rider feedback combined with the comments we hear from AER48 owners we have decided to offer a spring conversion kit for the WP AER48 forks. This kit installs in the left side fork only replacing the internal pressurized cartridge to eliminate the need for air pressurization of the fork.

With the Factory Connection spring conversion kit installed the fork is held up by a steel spring. The chance of an air leak causing a fork collapse or sticking is eliminated. The need to check and set air pressure is no longer there as the “air spring” is completely removed and replaced with the traditional coil spring set up. The kit has external spring preload adjustability with a range of 9mm; one turn of the preload adjuster equals 1mm of preload on the spring. Depending on spring rate and oil levels used the kit adds about 2.8lbs to the total weight of the bike.

With the kit installed the feel to the rider is greatly improved on all terrain types. The front end feels more connected to the ground inspiring confidence on corner entry with better front end “bite”. The initial movement of the fork is suppler giving improved hand feel; the bike will follow smaller ruts better with improved front to rear balance. Overall on back to back tests every rider chose the spring kit over the air every time.

This kit is installed by Factory Connection only and is recommended in conjunction with a Revalve. The cost of the kit with the correct spring rate is $674.90 plus labor, fluids and wear parts. For riders that already have a Factory Connection Revalve; or are happy with the current damping performance of the fork the kit can be installed as part of a Rebuild.

For more information please contact us at 1-800-221-7560.