Progressive Suspension has focused exclusively on American V-twin suspension since 1982, and its Monotube fork cartridges and 400/970/970G shock series are among the most common upgrades on baggers and Softails. For most riders the stock rear shock is the single worst part on the bike — this is the fix.
Transform your Harley-Davidson's front end with a Progressive Suspension Fork Cartridge Kit. This comprehensive upgrade replaces all OEM fork internals with high-performance gas-charged monotube dampers and custom-tuned progressive-rate springs. Experience a dramatic improvement in handling stability, cornering confidence, and braking control.
Why riders pick this
Replaces all OEM fork internals for a complete upgrade
Gas-charged monotube damper cartridges
Custom-tuned progressive-rate fork springs
Reduces front-brake dive and improves stability
Enhances cornering performance
Available in stock and lowered ride heights
A weak front end can compromise even the best V-twin. This Progressive Fork Cartridge Kit addresses common complaints like excessive brake dive and vague steering by providing a complete overhaul of your fork's damping and spring system. The result is a front end that stays planted, absorbs bumps effectively, and inspires confidence whether you're leaning into a turn or scrubbing speed.
Engineered for Superior Front-End Performance
Gas-charged monotube damper cartridges for consistent performance
Custom-tuned progressive-rate fork springs for optimal ride quality
Significantly reduces front-brake dive for better control
Enhances front-end stability and precision in corners
Available in both stock and lowered ride heights to suit your preference
A Foundation for Better Handling
The Progressive Fork Cartridge Kit is a foundational upgrade for any Harley-Davidson rider looking to improve their bike's dynamics. By replacing the outdated OEM internals, you gain a modern, high-performance suspension system that reacts predictably to road conditions and rider input. Whether you opt for the stock height or a lowered stance, this kit ensures your front end works in harmony with your rear suspension for a balanced and controlled ride. This is a must-have for riders pushing their V-twin's limits.
Specifications
Brand: Progressive
Manufacturer Part #: 31-2533
Category: Suspension / Fork Cartridge Kits
Weight: 10.05 lb
California Prop 65 Warning: Yes — Cancer and Reproductive Harm. www.P65Warnings.ca.gov
Common questions
What parts does this cartridge kit replace?
This Progressive Fork Cartridge Kit replaces all the OEM fork internals, including the dampers and springs inside your Harley-Davidson's fork tubes. The outer fork tubes themselves are reused.
Can I choose between stock and lowered ride heights?
Yes, you can select a kit that provides either a stock ride height or a lowered stance, allowing you to customize your bike's look and feel while improving performance. Be sure to select the correct version when ordering.
Will this kit help with front-end brake dive?
Absolutely. One of the primary benefits of this Progressive Fork Cartridge Kit is its ability to significantly reduce front-end dive during braking, providing a more stable and controlled stopping experience.
Ordering from Vtwinbikers
Brand new, sourced through authorized US distribution — never used, never grey-market.
Not sure it fits? Use Shop by Bike to filter by your year and model, or email us and we will confirm before you order.
Harley-Davidson and Indian Motorcycle is all we do, so you are talking to people who ride what you ride.
BRAND
Progressive
TYPE
Fork Cartridge Kits
SKU
T14-669279
WEIGHT
10.05 lb
Please contact us to confirm fitment for your specific motorcycle, or check the product title for compatibility notes.
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YOUR RATING
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✓ VERIFIED
Jun 29, 2014
The Feel is Greatly Improved
I replaced the the front and rear shocks on my 2013 Iron 883 and these both completely changed the feel of my bike! If you are going to do one upgrade on your Iron, replace both the front and rear shocks with Progressives. I could ride over a pothole the size of a moon crater and not even have to stand up with the 13" 444s. These fork cartridges dramatically improve the cornering and handling. I can't recommended these highly enough!
✓ VERIFIED
Apr 5, 2015
Super happy with these shocks
My ride: 2007 HD Sportster XL883L. The most critical test, an old set of train tracks halfway up a hill near my house. The grade goes level suddenly, has deep pot holes, really rough. Normally I bottom out hard. Went over that same spot after the Monotube fork kit was installed and the difference was amazing. It was like a different set of tracks. I love it when I spend the bucks and you know right away it was money well worth spent.
✓ VERIFIED
Feb 4, 2019
Awesome improvement
03 Ultra. Now it matches my Ohlins in the read. Great improvement over stock. No dive. Suspension is doing the work not my skeleton!
✓ VERIFIED
Jul 5, 2023
LOOK NO FURTHER
Installed in a 2001 Heritage Softail.<br />Top Shelf item. Easy to install. Made a world of difference in the handling of the motorcycle - braking, cornering, and overall ride. A life time guarantee to boot.
Progressive Fork Cartridge Kit - ...
$505.95
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