KroozR WP AER 35mm Big Piston Flow Kit Including Air Fork to Coil Spring Conversion Kit for 2020-on KTM / Husqvarna / Gas Gas 50cc Junior MX Racers

The OEM WP AER35 has a single coil spring in the right hand side fork leg and an air fork setup in the left hand side.

We recommend completely removing all the pneumatic system from your current left hand fork leg to replace it with a traditional coil spring and conventional damping cartridge matching setup in both legs.

The factory WP air system simply has too much fork 'stiction' (due to the large air piston) giving poor performance for light weight 50 and 65cc racers. Our dual spring conversion makes the fork's action more linear and consistent plus eliminates the need to constantly check air pressure. It gives the 35mm fork the smooth operation needed for lighter riders - improving turns and tyre grip with less front end wash outs.

Including our popular and proven Big Piston Flow Adjuster enables even more noticeable damping adjustment form Hard to Soft in both rebound and compression so that it is easily adjusted to suit all levels of rider.

This mechanism is engineered into the fork cartridge on the left hand side compression leg and offers a 're-valve' like feeling just with simple clicker adjustment on the fork cap. From a super plush easy fork action suited to beginners straight to a fork with hold up and smooth operation to suit the faster A-Grade riders in seconds. Easily adjusted on the comp side fork cap in seconds - it has fine machined increments to achieve fine and accurate settings.

This fork kit is also rebound adjustable but we find that not as much adjustment is required across the common spring rates from our recommended setting.

Parts included in the kit:

• Top Out Springs
• Spring Conversion Parts
• WP35 Flow Piston Assembly
• Optional Coil Springs (to suit rider weight)
• Step by Step Detailed Installation Instructions

Install Tools are required and available here:

Complete Tool Kit (All 3 tools)

Install Multi Tool 

35mm Tube Clamp

27mm Cartridge Clamp

Key Features:

• Never have to set your air pressure ever again
• Flow Adjuster mechanism installed to compression leg offering superior compression adjustments over our competitors
• Ease of tuning for various rider speed and levels
• Much more reliable fork
• No fade out or pump up in pressure over long motos - highly noticable on these 65cc machines. We are measuring 3-4psi over 20 minutes at a high level!
• A constant feel in your front end that is more consistent throughout the ride
• User manual included

Fork Spring Rate Recommendation

Fork springs need to be purchased to match this kit. These recommendations are a guide only as fork springs are weight and speed dependent. Match with a single spring or a pair of new springs to your suspension tuner's recommendation. This guide is for rider weight without gear.

Please Note: some springs listed are not available as a pair and two separate springs need to be purchased.

For more accurate advice please contact us.