Progressive Suspension Buying Guide

By Glenn Zetterquist (Zee331)

Have you ever gone into a corner and your bike began to wobble like no other? Have you hit a pothole and been bounced right out of you seat? While riding 2-up, have you ever hit a bump and completely bottomed out?

These are effects of poor suspension or improper suspension setup. The suspension of our motorcycles is one of the three most important things (Suspension, Seat, Tires) that isolate our bodies from the gyrations of the road such as potholes, bumps, and other inconsistencies. In this buying guide, we will talk about how and why an aftermarket suspension upgrade will benefit you and your motorcycle.

You will learn how to:

Eliminate the following: Get the benefits of:
Sharp Jaring Smoother Ride
Bottoming Out Plush Suspension
Cornering gyrations Confident Cornering
Brake Dive Solid Braking
Much more! Staying In Your Seat

Click here to Shop Progressive Suspension products at Cruiser Customizing.

All motorcycles come from the factory with “suspension” so why would you want to or “need to” replace those components? Well, three reasons come to mind: performance upgrade, replacing worn out components or replacing damaged components.

1. Performance Upgrade: Our motorcycles were built at the factory on an assembly line and budgets were in mind... suspension is a not-so-seen component and therefore is less focused upon during the build process. Many riders feel the “jarring effects of the road” and chalk it up to being “normal.” But this doesn’t have to be! Better quality and more “performance orientated” solutions are available which will provide you a smoother and more responsive ride. Aftermarket suspensions are usually progressively wound, and feature quality materials such as billet aluminum, brass valves, and superior technology.

2. Worn Out: Just like anything else on our motorcycles, suspension components are moving constantly as we ride... and they wear out. Manufacturer specifications suggest (depending on the manufacture, make and model) motorcycle fork springs and shocks be replaced every 40k to 60k miles for best performance. Most aftermarket suspension components are rebuildable or serviceable, and will last much longer than most OEM suspension components. In addition, aftermarket components normally cost the same as OEM components and are much better quality, providing a substantially smoother ride.

3. Damaged: If for some reason your OEM suspension components fail or get damaged in a fall, this is the perfect time for an upgrade! OEM replacements can be costly without giving any additional benefits. In addition, you should not run suspension on one side of your bike that has “seen mileage,” and a brand new one on the opposite side. Each side of your motorcycle is different, and will not respond the same- this can be dangerous. Use this as an opportunity to upgrade to Progressive Suspension and improve your motorcycles ride quality.

The term “progressive suspension” is thrown around often in the motorcycle space... yet few really understand what it means. Yes, Progressive Suspension is the brand name of one of the most known and trusted aftermarket manufacturers of motorcycle suspension products. But the term progressive suspension refers to progressively wound springs or springs with progressive rates. (See Image) A standard rate spring has equal compression rate for each inch of compression. In the example, it takes 100 pounds to compress the spring each inch. In the progressive rate spring example, the 1st inch takes 60 pounds, 2nd inch takes 75 pounds, 3rd inch takes 100 pounds, and the 4th inch takes 120 pound of pressure. This means the OEM or standard rate spring is very harsh for light hits and has no variance when encountering varying obstacles. The progressive rate spring will give different “suspension results” with every obstacle encountered.

Progressive Suspension

As with anything, there is a good, better best and suspension (similar to electronics), and you get what you pay for. Generally, a less expensive shock will have “less technology” and less expensive components built into the setup. Examples would be stamped steel housings vs. billet aluminum housings. Rubber bushings vs. polyurethane bushings. Standard rate springs vs. progressive rate springs. Adjusters which require a tool vs. tool-less adjusters. Standard dampening or Frequency Sensing Technology.

Choosing the right shock / suspension for your application can be tough. Balancing cost, with function, quality, style, stance and ride can be tough. Most suspension components from Progressive come in three sizes (or length) and each size is available in either a standard or heavy duty application.

Sizes or Lengths

Shorter: Bike will sit 1 to 2 inches lower than stock and will have LESS ground clearance and decreased cornering abilities.

Slammer Kits are available which give your bike that “Slammed Look” which looks awesome and is perfect for riders with shorter inseams.

Stock: Same length as stock so the bikes stance is unchanged but will have significantly better suspension characteristics.

Longer: Bike will sit taller than stock, which will give it more suspension travel and more ground clearance which will enhance cornering abilities.

Standard vs. Heavy Duty

Standard = Rider weighs less than 250 pounds and seldom rides 2-up.

Heavy Duty = Rider weighs more than 250 pounds and often rides 2-up.

Custom Applications

Air Shocks: Air shocks use compressed air instead of steel springs to give the user total control of their ride height, shock pressure which provides a smooth and consistent ride and in most motorcycle applications it is self-leveling. One downside, if the engine is left off for an extended period, the motorcycle will gradually settle to the ground.

Remote Reservoir Shocks: These are race inspired shocks developed for riders who want more out of their suspensions than just the average cruiser. Most of these types of shocks combine a high pressure gas monotube design with deflective disc damping routed through two unique circuits and adjustable for compression damping via an easily accessible knob.

Once you have purchased your fork springs or rear shocks you will need to properly “set them up” before you will be able to get the optimum ride from your new purchase. Both front fork springs and rear shocks must be adjusted or turned based upon the style of riding you are performing.

Front Forks: Many forks allow for preload and rebound adjustment via clickers and screws, but for most Harley and Metric cruisers this is not the case. For these bikes adjustment will come in the way of preload spacers installed in the top of the forks combined with the amount and viscosity of the fork oil used.

Rear Shocks: All Progressive Suspension shocks come out of the box in the “softest setting” and this is known as preload. The Preload of most shocks (OEM and Aftermarket) can be adjusted using a spanner wrench in the OEM tool kit or one provided with your aftermarket purchase. Adjustments can make to the shocks one click at a time or twist at a time if you have a tool-less shock. How many clicks to get the right amount of preload for your application? This depends on the load you place on your motorcycle and is determined by a measurement called “sag.”

Progressive Shock Progressive shocks

Spanner Wrench

According to Charlie (a Progressive Suspension Employee), the perfect amount of sag for most Harley Davidson and Metric Cruisers is between ¾” and 1-1/4.” This ¾” to 1-1/4” measurement is the distance between the “Free Sag Measurement” and the “Rider Sag Measurement.” (see image) Note, the Rider Sag measurement is “fully loaded” so if you ride 2-up, get both of you on the bike for measurement. If you ride “fully loaded” then load the bike completely up, sit on it and then take your measurement.

Perfect Sag

Now... just how do you determine how much sag you and your motorcycle has?

Follow these steps to find your current sag and then adjust your suspension accordingly.

1. With the bike empty (no rider & no luggage) measure the distance between the shock eyelets.

2. Load the bike with the rider / riders / luggage... however you plan to ride and take the measurement between the shock eyelets.

3. The difference between these two measurements should be ¾” to 1-1/4”

A. If the distance is less than ¾” backoff the preload and remeasure. Repeat until the optimal measurement is achieved.

B. If the distance is greater than 1-1/4” advance the preload adjuster 1 click and remeasure. Repeat until the optimal measurement is achieved.

4. You are now set up to ride!

Helpful Hint: If you swap between fully loaded and riding solo, determine the perfect amount preload for both instances. Then, when you get ready to ride fully loaded adjust to that notch and then when you unload, you will know the perfect notch to adjust back to with no more measurements needed.

It’s now time for the fun part... researching and choosing the style of shock that is perfect for your ride!

Start researching / shopping today by clicking this link:


A quality suspension setup is an important and absolutely key component of your motorcycling enjoyment. Understanding how preload, rebound and sag affect your ride and how to properly set these key adjustments will keep you and your bike safely and more comfortably on the road for miles and years to come. We hope that this Progressive Suspension Buying Guide for 2013 has helped you to better understand your motorcycle and how it functions and how it can function even better!

Thanks for reading. Until next time, take care and ride safe!

Kyle & the CC Team.

Side Note: The author of this article (Kyle Bradshaw) currently rides with progressive suspension on his 2003 Honda VTX1300 as well as his 2006 Honda Goldwing. He says that suspension is one of the best accessory upgrades he has made to these machines.

Read what members have to say about their Progressive Suspension Purchases:

Stars Luis (storem) from Kissimmee, FL, United States, for a 2005 1600 Vulcan Classic wrote:
Very easy to instal and it lowers the motorcycle nicely. I had a hard time with the instructions (ref the spacer size), because they do not have specific instructions for the Vulcan Classic 1600. I called Progressives Tech Dept and eventually I got a hold of the lead tech. He was friendly and told me exactly what I needed to do. I gave the product a 4 for instal because of the lack of clear instructions for my model.

Stars(specialknine) from Canberra, , Australia, for a VS 750 1985 800 Intruder wrote:

Easy to install. Once on, I just road up and down the same stretch of road. Each time I returned I gave the shocks a one click adjustment until i found a comfortable position. What a smooth ride now. No more jarring of my back when hitting large dippers in the road
Review Details

Stars(brad869) from Australia, for a Dyna Glide wrote:

good looking shocks if u wanna black out your bike whilst adding some extra comfort then they are a great buy
Review Details

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