Welcome back to another Hot Bike’s Tech Tips. In this installment, we are going to cover front and rear suspension basics on one of the late-model Softails, a 2022 Low Rider ST.
So, what is the point of suspension? Some people might say that a motorcycle suspension’s purpose or function is to make the ride more comfortable. That’s actually not the case. While a good suspension setup or a finely tuned application can, and does, make the ride more comfortable, ultimately, the main point of suspension is to keep the tire in contact with the road. When your tires are not in contact with the asphalt then basically you have no control of the motorcycle, which is obviously not ideal.
Harley-Davidson has two styles of front suspension: A conventional style front fork and an inverted front fork (or upside-down fork). Up until recently, most Harley-Davidsons have been equipped with conventional front forks, but with performance being the name of the game with riders these days, a lot of Harleys nowadays come equipped with inverted front forks from the factory. And they work pretty well. This particular model, the ’22 Low Rider ST, has the inverted front fork, which is more complicated to work on, but far superior in terms of functionality. There are people that make an entire career out of building and tuning suspension. It’s an art much like engine building, but it’s not talked about as much.
To be clear I’m not a master-certified suspension tech, but I do understand suspension and want to explain some basics so you know what we’re talking about here. Then you can make a more informed decision when making a purchase on some potentially costly new suspension products for your personal bike.
So, what’s the difference between an inverted front fork and a conventional? A conventional frontend’s fork tubes are what are anchored into the triple tree. The tubes are the least rigid part of the front fork. When you lay the bike into a turn the lateral force can cause the fork tubes to flex. With an inverted front fork, the fork tube is at the bottom of the front fork. The strongest part of the front fork, the fork leg, is anchored into the triple tree, so it has far less flex when lateral force is applied.
Be aware, performance suspension installations, especially front forks, require quite a few special tools. You will fuck something up if you don’t use the right tools. Also, the forks are under spring pressure so be careful when tearing down because the steel preload tube can jump out and cut you pretty good.
For this performance suspension application, we are using a GP cartridge kit for the Low Rider’s frontend. Our specific GP kit ($1,499 as assembled) includes the model-specific Low Rider ST cartridges ($1,379) and 35.1x260x1.05 KG 10.29 N/mm fork springs in each (add $60 for each fork leg, $120 total). The new GP frontend is fully adjustable and handles like a dream. The stock suspension is good, but the GP suspension is great. It feels like a completely different motorcycle once installed. It also comes set up pretty close for your weight. When we ordered the kit from GP we simply provided some basic rider information and it came set up to our specs close enough that all you need to do is fine tune it to your personal taste.
We are also changing out the stock tubes for black tubes. To do this you need to remove the fork feet. There is no magic involved in doing this, they simply thread onto the tube. To get them off you need to throw some heat at them and use the axle to unscrew them. The threads are really fine so take care when putting them on your new tubes to not cross thread them.
The Milwaukee-Eight Softail features a monoshock frame, meaning it has one rear shock that rides in the center of the frame attaching to the top of the swingarm at its center.
Note: Certain 2018–2023 Softails have been recalled for rear suspension mounting bolt failure. The bottom bolt can shear, causing damage to the rear tire. A damaged rear tire can result in a loss of tire pressure, increasing the risk of a crash. While we were replacing the rear shock, we obviously needed to replace the bolts too.
For the rear shock in this performance suspension upgrade we went with a RWD 13.5-inch RS-1 Adjustable M-8 Softail Suspension system for 2018–2023 Softail models ($799). This shock has far more adjustability and better valving than stock. Much like the frontend, you’ll think you’re riding a different motorcycle. The combination of the GP Suspension fork internals and the RWD rear shock gives you amazing performance while still maintaining comfort.
The rear shock install is pretty straightforward. You will need to support the bike to take the pressure off the stock shock. It is held in with a large bolt at either end. At the swingarm there is a pinch bolt that needs to be undone. When installing the new RWD rear shock you will need to route the remote adjuster and mount it. This is also not hard to do, which we installed ours to the ST’s side cover.
All of the parts we’re covering here have superior fit and finish and are made specifically for you and your bike and can be fine-tuned based on your riding style and your riding specifications. Check out the subsequent YouTube video above.
Until next time ride safe and have fun on your motorcycle.
Source : Hotbikeweb
