Softail FXLRS Fork Cartridges
In the Harley-Davidson Softail M8 range, the Fat Bob and Low Rider S/ST models come with the same upside-down forks. Thanks to this fork, these motorcycles feel noticeably stiffer on the move and steer better than other Softail models.
Unfortunately, stiffness is the only advantage of the upside-down fork, because only one leg has an open damper with an obscure valve inside (we didn't notice a pronounced difference between low-speed and high-speed compression). The second leg has no damper at all, only a spring.
Progressive Suspension uses a similar configuration in its Harley-Davidson kits, but with a much larger-diameter damper (higher energy absorption), a sealed pressurized monotube and an effective FST valve that automatically adjusts resistance depending on the frequency of oscillations.
Since we had already fitted a Legend air shock at the rear, we decided to fit cartridges from the same brand at the front.
Each Legend cartridge has a monotube damper pressurized by a compressed nitrogen chamber under the top cap. Pressurized oil doesn't foam under impacts and heavy loads, which keeps the damper working consistently.
The drawbacks of this design include the lack of compression and rebound adjustments. Even preload is set when the cartridges are installed and can't be changed without disassembly.
To provide adjustments in the top cap, adjustment rods must reach the piston in the damper. But Legend's cap holds a compressed nitrogen chamber separated from the oil by a floating piston, which makes it impossible to fit adjustment rods. In our opinion, for city use pressure is more important than adjustments.
We have fitted Legend cartridges in conventional forks many times and have always been happy with the result. The factory setting of the damping is quite adequate and takes a passenger into account. Riding solo, the fork can be a bit stiff, but it's always stable, reliably presses the wheels to the road on bumps, recovers quickly after hard impacts and is much more resistant to bottoming out.
Installation isn't difficult, but the HD upside-down fork requires a special socket to unscrew the spring stop in the right leg.
It's very important not to damage the right cartridge's locknut during installation. In the video we tighten it with an adjustable wrench with plastic jaws. This nut also works as a centering guide and rubs against the walls of the aluminum tube. If you damage it, it will leave scoring on the tube walls, plus it will create extra resistance as the fork works.
It's important to fill the oil according to the instructions, since the wrong amount can lead to the fork locking up, incorrect operation or rapid cartridge wear.
Test rides showed a very big difference in stability and steadiness, which is strongly felt in the load on your hands. With Legend cartridges you can accelerate and brake to zero holding the handlebar with one hand: the motorcycle goes straight, without veering to the side. On the stock motorcycle this wasn't possible, because the handlebar gets thrown from side to side and you have to actively correct, and with one hand that's scary and unsafe.
Stability is the most significant difference, which greatly affects steering fatigue and safety under braking. The bike feels lighter on the move and dives less under emergency braking, the braking distance is shorter, but what we liked most is that it goes straight without veering. We couldn't compare on a bad road, since our bike has higher ground clearance because of the air shock, so it can ride where the stock one can't. Small bumps are less noticeable and don't hit the handlebar as hard as on stock.
In our motorcycle shop you can get advice and buy and install suspension from leading brands. We work with Legend, Bitubo, Ohlins, Progressive Suspension, RaceTech, Wilbers, Russ Wernimont Designs, Hyperpro, Drag Specialties and ThunderMax.
