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DK Custom Front Suspension Testing Report - Part I of II

Front Suspension Testing Report

Part I

This is our Third Update of The Front Suspension Testing Report.

How We Tested:

Everyone’s perception of what is a good ride can vary.  So we employ the butts of more than a few folks.


Like our Rear Suspension testing, we have tested some front suspension on a suspension dyno (Damper Dynamometer).  However, the more important testing is on two test courses we have on the street, since ride quality is what really matters.


We used 3 Sportsters,  2 Dynas, a Heritage Softail, a Street Glide, an Electra-Glide, an Ultra, a Freewheeler and a 3 Tri Glides.


We ran solo, 2-up, & loaded down with luggage.


Our focus was on how it felt, and how it handled, in a variety of situations-


On the Two Test circuits we rode:

  1. Slowly

  2. Cruising speed

  3. Fast.




Specific Ride Compliance Testing Strategies-

Riding two circuits, with straights, curves with smooth & bumpy surfaces.  We rode over the same bumps & dips under acceleration, cruising and braking conditions.


Safety & Tire Wear Compliance Test:  With the front brakes applied and the throttle applied, we hit a sharp edged bump, as well as 2 rounded bumps to see if the tire stayed in contact with the road the entire time. 


Tested front end brake dive by hard braking


Taking corners for stability and road “feel” under acceleration and braking (not recommended).


Riding solo, 2-up & loaded.


Pulling wheelies (not on the Softail) and seeing what it felt like coming down.

What We Tested & Compared In Report Below

Stock Configuration

Stock springs with corrected Sag

Progressive Springs 

Racetech Springs


Gold Emulators

Pro-Action Fork Kit

Progressive Monotube Cartridge-Standard

Progressive Monotube Cartridge-Asymmetric

Progressive Monotube Cartridge-Frequency Sensing Technology

Legend Axeo (3 latest model variations)

Ohlins FKS (NIX) Cartridge Kit 

AK-20 Cartridge Kit

A variety of fork oils

To keep the report from being excessively large/confusing, we have not listed all the products we tested.   What we have left off the report are some that produced less than favorable results, nor have we listed some of the products that were very expensive and produced results no better than significantly less expensive options.

Test Results  (some of these need the pricing updated, please arrange them in price order)

In all our testing, the stock suspension was consistently the least favorable, and the AK-20 Cartridge was the most favorable. For grading we used the stock as a reference # of 0, and the AK-20 as a reference # of 100.  

Everything else was awarded points between 0-100, based on how much better they are than stock, and how close they are to the AK-20 Cartridge Kit.


 Front Suspension Report



XL- Sportster Models

FX- Dyna & non-floorboard equipped Softail Models

FXS- Non-floorboard equipped Softail Models

FLS- Floorboard equipped Softail Models

FLH- Touring & Trike Models




* The RaceTech High Performance Springs were given a 35-40 because they were a little stiffer, which was preferred for road feel with aggressive riding, but not as plush a ride for cruising.  Conversely, the Progressive Springs were a bit plusher ride, but not quite as good of a feel for aggressive riding.


****With the Gold Valve Emulators that are quite a few extra steps in the installation process, including complete disassembly of the forks, drilling holes in the Damper Rods, and reassembly.  Because the Intiminators produce just as good a result, and are much easier to install, we prefer them.



Click HERE for PART II

Live Free - Ride Free!