PROGRESSIVE SKU: T14-613980

Progressive Fork Cartridge Kit - Harley-Davidson

$632.95
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About Progressive

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.

This Progressive Suspension fork cartridge kit is engineered to transform your Harley-Davidson's front end performance. It replaces the factory fork internals with advanced gas-charged monotube damper cartridges and custom-tuned springs. The result is a significant improvement in ride dynamics, offering better stability and control.

Why riders pick this

  • Replaces OEM fork internals with advanced cartridges
  • Reduces front-end brake dive for better control
  • Improves stability and confidence in corners
  • Custom-tuned springs for optimal damping
  • Available in stock and lowered ride heights

Factory Harley-Davidson forks can often feel undersprung or underdamped, especially when pushed hard. This Progressive fork cartridge kit addresses those shortcomings by providing a complete overhaul of your front suspension. Riders will immediately notice reduced front-end brake dive during heavy braking and a more planted feel through corners, inspiring greater confidence on every ride.

Superior Front-End Control

  • Features gas-charged monotube damper cartridges
  • Includes custom-tuned fork springs for optimal performance
  • Significantly reduces front-end brake dive
  • Enhances cornering stability and control
  • Improves resistance to bottoming out

Dial In Your Ride Height

Beyond performance, this kit offers versatility in setting up your bike. With options for both stock and lowered ride-height versions, you can tailor your Harley-Davidson's stance to your preference or riding style. Whether you're looking to maintain factory geometry or achieve a more aggressive, lowered look, these cartridge kits provide the flexibility to get your front end dialed in just right.

Specifications

  • Brand: Progressive
  • Manufacturer Part #: 31-4004
  • Category: Suspension / Fork Cartridge Kits
  • Weight: 9.7 lb
  • WARNING: Cancer and Reproductive Harm — California Prop 65. www.P65Warnings.ca.gov

Common questions

Will this kit reduce brake dive under hard braking?

Yes, the gas-charged monotube design of these cartridges is specifically engineered to resist compression during hard braking, keeping the front end more stable.

Does this kit offer different ride height options?

Yes, this Progressive fork cartridge kit is available with options for both stock and lowered ride heights to suit your preference.

Is this a universal kit for all Harley-Davidson models?

While designed for Harley-Davidson, specific fitment varies by model and year. Always verify compatibility for your exact bike before ordering.

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.
BRANDProgressive
TYPEFork Cartridge Kits
SKUT14-613980
WEIGHT9.7 lb
Please contact us to confirm fitment for your specific motorcycle, or check the product title for compatibility notes.
CUSTOMER REVIEWS
4.85
75 RATINGS
5★ 66
4★ 7
3★ 2
2★ 0
1★ 0
✓ VERIFIED
Mar 19, 2017

Quality Product

I recently installed a set of monotubes on my 2013 FLTRX. The suspension installs easily but I strongly recommend using your manufacturer's service manual in order to avoid any issues with the disassembly or reassembly.<br /><br />I bought the 2inch lowering kit but chose to only lower it a little over an inch. This is accomplished by fine tuning the setup with the supplied preload clips. I ride 2-up often so I chose not to "slam" the front end but still closed the gap between the fairing and front fender a noticeable amount.<br /><br />Satisfied with my purchase and quick delivery.

— Ryan R
✓ VERIFIED
Mar 27, 2020

Performance Bagger

Don’t bother pumping up your motor if you’re not going to build a suspension that can keep up with the added power. I did motor work first just to find out that my stock suspension was not meant for the added power. A little shaky at high speeds and wandering through sweepers not to mention nose diving when braking for tight corners. <br /><br />I added a rear stabilizer, 944’s, and Heavier fork oil and things got a lot better but not where I wanted it. Still had too much brake dive and liked to wander around in high speed sweepers. <br /><br />I added a front stabilizer and found it tightened things up a bit but that outdated hydro front end was still the weak link. <br /><br />Installed the Monotubes which was not very difficult at all on a Road King (No Fairing to deal with). I’m happy to say that my motor is finally not out running my suspension. No Brake Dive, No wandering through sweepers, and straight as an arrow at higher speeds. In 09 they made good improvements to the frame but they should have contracted the suspension out to progressive. <br /><br />Thanks PS and RZ for getting these Monotubes out to me so I could finally get my bike dialed in!

— Dwayne N
✓ VERIFIED
Jul 29, 2019

solid and firm

installed on 2013 FLHR.. 200lb solo rider.. debated and read alot of reviews before this purchase.. installed new 21 front and 17 rear.. (front end rise was 1") -kit dropped front end 1" and used 1 spacer for weight. front end now feels very heavy. ride is firm but not harsh.(did not like this ride) -lowered back air to 10lb and now front feels better balanced..bars now feel to far forward as well as windscreen is lowered.. bike feels planted, wheel does not wander and tracks well.. no issues with speed wobble, slow speed turn is slower, but still ok.. if i was to do over i would order standard monotube..

— brett w
✓ VERIFIED
Mar 22, 2019

Great ride

I’m really happy. My 2006 roadking rides sooo much better. Wish I would’ve done this upgrade sooner. Easy to follow install instructions. I did have to call support for a question. Good customer service with progressive. ??

— Mitchell L
✓ VERIFIED
Nov 4, 2017

ride

the progressive monotube cartridge kit for harley is well worth the cost it has really made a difference in the ride and handling of the bike 2004 ultra 112,000 also i replaced the rear shocks with progressive 412 better than new. also revilla great service and friendly

— gene s
✓ VERIFIED
Jan 18, 2020

Great product

I recommend to all who love their baggers and want better handling. Best upgrade so far.

— Ryan H