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Progressive Suspension Monotube Fork Cartridge Lowering Kit

J&P Cycles Part Number: 137-680

Manufacturer Part Number: 31-2518

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Description for Progressive Suspension Monotube Fork Cartridge Lowering Kit

•Lowered version of [BRAND] Monotube Fork Cartridge kits, this kit will lower the front end of your bike up to 2”

• True high performance and increased comfort is provided with this kit by upgrading the technology your front forks are using

• This state-of-the-art monotube fork Kit represents the pinnacle of front end handling

• High performance specialty components replace the sloppy open bath damping found in stock H-D forks

• The kit features a set of gas charged monotube fork cartridges and a set of custom tuned fork springs, and is a complete direct replacement for your stock internal components

• Improved resistance to front brake dive

• Improved front end stability

• Improved cornering

• Improved bottoming control

Product Specs

Product Specs for Progressive Suspension Monotube Fork Cartridge Lowering Kit

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Compatible Models

Harley-Davidson® Models

  • Sportster 1200 Forty-Eight XL1200X : 2010–2015
  • Sportster 1200 Nightster XL1200N : 2007–2012
  • Sportster 883 Iron XL883N : 2009–2015
  • Sportster 883 Low XL883L : 2007–2010
Customer Reviews

Customer Reviews for Progressive Suspension Monotube Fork Cartridge Lowering Kit

Overall Rating

5 out of 5 stars (based on 14 reviews)

5 stars (14)

4 stars (0)

3 stars (0)

2 stars (0)

1 star (0)

0 stars (0)


I love this kit. The responsiveness is just right. Incredibly easy installation.


Worth every penny .


A vast improvement to handling over the stock suspension.

gary st.

Perform better than expected,would rate as one of the best upgrades for your Harley,s


Great fit. Better ride.


Rides like a dream.


Easy to install with the right tools. Instructions are a little lacking but the Progressive web site has great videos that helped.


The best way to lower a bike after installing a 21" front wheel. It actually rides better than stock.


I'll admit I was on the fence about if these monotubes would really make much of a difference. I am BLOWN AWAY at how much of a difference they made. It's hard to explain, but it really is like if you have ever driven a high end sports car, everything just feels tight and responsive, firm, but not hard. These were worth every penny, hell... i'd of paid twice as much knowing what I'm getting now. It's unbelievable how sloppy the stock HD suspension is.. and you probably won't even know it until you put this upgrade in. I have my rear end lowered 2", so I lowered the front 1" and my bike feels great. 2013 Street Glide.


Lowered the front one inch on my 2008 Street Glide. Wish I had done it sooner.


Best value for the money


Great product! Instructions were exact, and tech support was second to none... Very pleased!

1996 roadking

Good price, easy installation, great quality, I give it a 10

Sean Coleman

I just got the new shock cartridges installed and they are wonderful! Less nose dive on heavy braking, and very little front end lift on acceleration. This translates to a more controlled ride and is exactly what I was hoping for.

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