(1.) The Progressive Suspension fork lowering kit is fairly simple and includes shorter main springs, preload spacers, and additional top out springs. Adding an additional spring per fork leg will lower the bike 1 inch. Adding two top-out springs per leg will lower it 2 inches.
(2.) Although not particularly difficult, due to the fairing fork removal can be rather tedious and as such, we'll skip directly to disassembly of the legs. For more details on the frontend extraction, consult your manual. The entire process uses basic tools and begins with pulling the top cap.
(3.) Most fork legs are preloaded (meaning the spring is under a degree of tension), so caution should be taken when removing the cap.
(4.) Located at the bottom of the fork leg and fastened by a single bolt at the bottom of the fork, the damper rod has to be removed on each leg. This bike clearly needed fresh fork oil as well.
(5.) In addition to a shorter main spring, we've added a second top out spring. This essentially pulls the upper and lower together, creating a shortened leg and lower bike.
(6.) Chosen for their high pressure gas mono tube design and plush deflective disk damping the Progressive 430 Series shocks are pretty cool looking as well.
(7.) The bike was lifted just enough to release the weight on the rear wheel and the bags removed to access the shocks. The original shock on a Street Glide is already 1-inch lower than most other baggers so we'll stick with that height.
(8.)Removal of the OEM parts is fairly simple and involves only four bolts. The hardware is retained and will be reused with the new shocks.
(9.) The 430 Series shocks are a straight bolt on and come with a detailed instruction sheet. We did the swap in about 15 minutes.
(10.) Setting preload is critical to ride quality and tuning the Progressive shocks only involves a few turns of the top caps. We ran these three turns in of a possible six, which left substantially more adjustment if we needed it.
Fork Lowering Comparison Chart
The void created by a shorter main spring (in order to lower the bike) is filled with a Compensation Spring (shown in red).
Once the bike is taken off of the jack and weight of the bike is loaded on the suspension the spring goes to a solid.
Performance Suspension for Your Performance Bike
In the mad rush for bloated horsepower, chromed nut covers and the latest in leather wrapped loveliness, it seems the importance of ride quality is often overlooked. Big power, speed, and stump-pulling torque are cool and all, but of very little use if your bike won't go around a corner or handle a few bumps in the road.
With that in mind, we took some time to visit the folks at Progressive Suspension to see how they deal with the ins and out of up and down. With just under 30 years of ride control under its belt, Progressive knows a thing or two about Touring bikes. We also brought along the cover bike from our June 2009 issue to act as our suspension guinea pig. It was immediately clear how serious these guys are as they quizzed us about rider weight, riding style and luggage capacity. Well, the Street Glide in question would be host to a 200 pound rider, ridden like a sport bike and would likely never carry more than an evenings worth of luggage. They seemed satisfied with our responses and recommended a pair of their 430 Series shocks and a fork lowering kit to help balance out the height added by a 21-inch front wheel on the Glide.
Since the Street Glide is already one inch lower than other baggers (12-inch shock length as compared to 13), we stuck with that height and based on rider weight stayed with the standard spring rate over the heavy-duty version Progressive offers. They also explained the 430 Series utilizes a state of the art high pressure gas mono tube design and deflective discs to handle the dampening duties as well as an easily adjustable preload cap. The fork kit they chose for us consisted of a progressive rate main spring and a handful of top out springs which provided the option of a one inch or two inch drop.
Install of this particular fork lowering kit required removal and disassembly of the legs but the Progressive guys now build another version (see sidebar) that does not involve disassembly of the legs. Fork preload is also tunable by adding or subtracting from the length of the spacer included in the kit. This machine would be ridden hard, so a little extra preload was added to keep it firm. Once the frontend was buttoned up, we moved on to the rear. All of the stock air lines as well as the shocks were binned and the 430s bolted up in under 15 minutes.
Spinning the top caps a few turns, Progressive set up preload (firmness) of the rear shocks to match the rider as well as showing us how to adjust it further if we decided to add a passenger or substantial amounts of luggage. The results were exactly as promised and the bike transformed from an ill handling monster to a touring bike that now rode as good as it looked.
Progressive's NEW Drop-In Fork Lowering Kit
Since this install was completed, Progressive Suspension has created an entirely new method to lower the frontend of your Harley. Seems the days of taking a fork completely apart and adding top out springs are behind us. Progressive's new Drop-In fork lowering kit is just that and can be done without taking the forks apart and on many bikes without even removing them! The heart of the Drop In kit is the Compensation Spring and its function is to take up the slack when the fork is fully extended (much like adding top out springs). The result is a lowered frontend that goes together in a fraction of the time and because it can still extend to full length it'll actually ride nicer. Take a look at the illustration below, it shows a comparison of a stocker, a Drop-In lowering kit, as well as the traditional style system we just installed. We'll do a detailed install with this new kit in an upcoming issue.
430 Series shocks, chrome
Fork Lowering Kit.10-1561