DK Custom Products

Phone: 662.252.8828
Text: 662.420.4891
Email: [email protected]

FST Asymmetric Fork Cartridge System Harley 14+ Touring & Trike

Availability: In stock
Item #: DK-PRG-MT-CTG-4
Manufacturer: Progressive Suspension

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DK Custom Front Suspension - Progressive Monotube FST Asymmetric Fork Cartridge System Harley 14+ Touring & Trike More Comfortable Ride suspension







2014-Up Touring & Trike* Models


Features & Specs:

  • Progressive Rate Spring
  • Gas Charged Damper Cartridge
  • Frequency Sensing Technology Valve (FST)
  • Improved Stability & Control
  • Improved Lean Angle
  • Reduced Brake Dive and Bottoming
  • Includes Spacer for Sag Adjustment
  • Lifetime Warranty
  • Includes Step-by-Step Instructions


DK Custom Products has tested numerous aftermarket suspension components.  We've logged well over 16,000 miles on a variety of bikes and trikes, covering an array of road condtions, loads and speeds.   All this, while paying close attention to the ride quality with various suspension configurations.

You can view our full report on our testing of various suspension components at this LINK.


 When you order let us know the year and exactly what Model HD you have, so we can send you the correct FST Cartridge System for your bike.


This FST Asymmetrical Fork Cartridge System is a breakthrough in Drop-In Cartridge Suspension.


Road smoothing Frequency Sensing Technology (FST) damper combined with a progressive rate spring, create a state of the art fork cartridge kit for the late model Baggers & Trikes.


The way it works? An asymmetrical layout places a progressive rate spring in one leg and an aluminum bodied, sealed cartridge damper on the other. The result is superior damping via the internal bypass of the FST valve, increased ride control and a new benchmark for high performance front suspension.

You can experience surprising improvements in-

Cornering, small & large bump absorption, reduced brake dive and overall stability and road feel.



2014-Up Touring

*Trike Models 2014-2018 (2019+ is coming shortly, but not available for the Trikes right now)


It is necessary to change the fork fluid when installing these FST Cartridges.  We recommend Maxima Racing Formula Fork Fluid. 

Fork fluid is something you can get locally, or use the option to add it to your order.

 More Plush Ride- 2 liters of 10 Weight

 More Aggressive Ride- 2 liters of 15 weight


 You can see our grading of these FST Monotubes & other suspension components HERE.


Save $ with a Special Package

 See Stage I, II, & III Total Suspension Upgrades HERE.


*Special package pricing is available only when purchased via the Stage I, II or III upgrades at the above link.  Applying the savings After ordering the components individually actually costs us more $, so no additional savings are available after the fact.

Customer Reviews

Working well Review by Dave
I have a couple thousand miles on these now. Working better than stock set up for sure. You don't need 2 bottles of fork oil. (Posted on 4/14/2020)

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