--- product_id: 14275317 title: "Progressive Suspension 444-4001B Black 12.5\" Standard Big Mile Riders Rear Suspension Shock" brand: "progressive suspension" price: "40628037₫" currency: VND in_stock: true reviews_count: 7 category: "Progressive Suspension" url: https://www.desertcart.vn/products/14275317-progressive-suspension-444-4001b-black-12-5-standard-big-mile store_origin: VN region: Vietnam --- # Hand-adjustable spring preload, no tools needed Progressive rate spring for smooth ride Frequency Sensing Tech for adaptive damping Progressive Suspension 444-4001B Black 12.5" Standard Big Mile Riders Rear Suspension Shock **Brand:** progressive suspension **Price:** 40628037₫ **Availability:** ✅ In Stock ## Summary > ⚡ Elevate your ride with smart suspension that adapts on the fly! ## Quick Answers - **What is this?** Progressive Suspension 444-4001B Black 12.5" Standard Big Mile Riders Rear Suspension Shock by progressive suspension - **How much does it cost?** 40628037₫ with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.vn](https://www.desertcart.vn/products/14275317-progressive-suspension-444-4001b-black-12-5-standard-big-mile) ## Best For - progressive suspension enthusiasts ## Why This Product - Trusted progressive suspension brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Tool-Free Tuning:** Easily adjust spring preload by hand—fine-tune your ride in seconds without any special tools. - • **Precision Engineering:** Deflective disc valve optimizes damping response for a silky smooth ride on any road. - • **Built to Last & Perform:** Durable chrome finish with a progressive rate spring ensures both style and superior shock absorption. - • **Ride Smarter, Not Harder:** Frequency Sensing Technology dynamically adapts to every bump for unmatched comfort. - • **Upgrade Your Ride Instantly:** Raise your rear end by 1.5" and eliminate bottoming out—feel the difference from the first mile. ## Overview The Progressive Suspension 444-4001B Rear Shock features cutting-edge Frequency Sensing Technology that automatically adjusts damping based on road conditions, a hand-adjustable spring preload for effortless customization, and a durable progressive rate spring with chrome finish. Designed specifically for street-cruiser motorcycles, it delivers superior ride quality, reduces bottoming out, and enhances overall handling without requiring special tools. ## Description After more than a decade of ruling the roads with the road proven 440 Series shocks, unveiled another breakthrough design. Dubbed Frequency Sensing Technology (FST) for its unique ability to dynamically adjust damping as you ride. The result is superior performance no matter the road conditions. A top mount threaded preload adjuster allows for fine tuning with a simple twist of the cap. Deflective disc valve. Adjust spring pre-load by hand, no special tool needed. Progressive rate spring. Standard spring rate and chrome finish. Review: worth the money - These shocks are awesome. I installed them on my 2011 Sportster 48. Raised the rear end by 1.5". It sat a little too low for me, I'm 5'11". My ride is much better, the stock shocks were garbage and always bottomed out. The change was like night and day. I also installed the Progressive monotube spring kit on the front and it rides like a brand new bike. This company makes quality products. The hand adjustment is very easy to do. I had a friend help me and we installed the shocks in about an hour. Neither one of us are mechanics and we weren't in a hurry. Just follow the directions, there are spacers you need to use. Review: For the price they give a very good ride on my Road King - A big improvement over the factory air shocks. They have near three inches of travel, so for me there is no topping or bottoming out. For the price they give a very good ride on my Road King. I could see no reason to spend hundreds of dollars more for premium shocks to get a slightly better ride when these fit the bill. ## Features - Frequency Sensing Technology (FST), allows the shocks to sense the frequency of a bump and automatically adjust damping for superior ride quality - Deflective disc valve - Adjust spring pre-load by hand, no special tool needed - Progressive rate spring - Standard spring rate and chrome finish ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B007GRGTKA | | Auto Part Position | Rear | | Automotive Fit Type | Vehicle Specific Fit | | Best Sellers Rank | #3,831,382 in Automotive ( See Top 100 in Automotive ) #3,667 in Powersports Shocks #99,484 in Powersports Body Parts | | Brand Name | Progressive Suspension | | Compatible with Vehicle Type | street-cruiser-motorcycles | | Customer Reviews | 3.6 3.6 out of 5 stars (8) | | Exterior Finish | Chrome | | Included Components | SHOCK | | Item Type Name | PS: 444-4001B HARLEY SHOCK 12.5"BLACK | | Item Weight | 8.2 Pounds | | Manufacturer | Progressive Suspension | | Manufacturer Part Number | 444-4001B | | Material Type | Chrome | | Model Number | 444-4001B | | Style Name | Unique,Fine | | UPC | 953040127391 | ## Product Details - **Auto Part Position:** Rear - **Brand:** Progressive Suspension - **Exterior Finish:** Chrome - **Style:** Unique,Fine - **Vehicle Service Type:** street-cruiser-motorcycles ## Images ![Progressive Suspension 444-4001B Black 12.5" Standard Big Mile Riders Rear Suspension Shock - Image 1](https://m.media-amazon.com/images/I/5173vPS3QiL.jpg) ![Progressive Suspension 444-4001B Black 12.5" Standard Big Mile Riders Rear Suspension Shock - Image 2](https://m.media-amazon.com/images/I/41Op2DcIWaL.jpg) ## Customer Reviews ### ⭐⭐⭐⭐⭐ worth the money *by H***Y on October 25, 2014* These shocks are awesome. I installed them on my 2011 Sportster 48. Raised the rear end by 1.5". It sat a little too low for me, I'm 5'11". My ride is much better, the stock shocks were garbage and always bottomed out. The change was like night and day. I also installed the Progressive monotube spring kit on the front and it rides like a brand new bike. This company makes quality products. The hand adjustment is very easy to do. I had a friend help me and we installed the shocks in about an hour. Neither one of us are mechanics and we weren't in a hurry. Just follow the directions, there are spacers you need to use. ### ⭐⭐⭐⭐⭐ For the price they give a very good ride on my Road King *by S***R on August 10, 2014* A big improvement over the factory air shocks. They have near three inches of travel, so for me there is no topping or bottoming out. For the price they give a very good ride on my Road King. I could see no reason to spend hundreds of dollars more for premium shocks to get a slightly better ride when these fit the bill. ### ⭐ Would not recommend them to a friend *by R***L on March 8, 2018* Way too much work for the price. First up, then down, and then back again. Adjustments sleeves are very tight and hard to move. There's no reference point when doing adjustments so it was hard to keep track of exactly how many turns you have in or out of them. Would not recommend them to a friend. --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.vn/products/14275317-progressive-suspension-444-4001b-black-12-5-standard-big-mile](https://www.desertcart.vn/products/14275317-progressive-suspension-444-4001b-black-12-5-standard-big-mile) --- *Product available on Desertcart Vietnam* *Store origin: VN* *Last updated: 2026-04-26*