LUC’S TIPS AUGUST 2013: Don’t Get Forked By Your Forks
Last Updated: April 1st, 2024
Oddly enough, the average motorcyclist doesn’t pay much attention to one of the most important systems of the motorcycle: SUSPENSION. Making sure our suspension is operating properly is key to our job as traction managers (also known as motorcyclists). Fork fluid is a key element to keeping the rubber on the road. So what do we need to know about it?
WHAT DOES FORK FLUID (oil) DO?
Simply, the fork fluid helps with the damping properties of the fork, including rebound and compression damping. By damping, we mean the fork oil helps control the spring’s energy by dissipating the spring’s energy into heat. The fork oil accomplishes this mission by being directed through orifices or valving systems. As the fluid rushes through the holes or valves, friction is created and heat is generated.
WHY DO I NEED TO MAINTAIN THE FORK FLUID?
We care about the condition of the fork oil because as the oil ages, it breaks down and its ability to convert the spring’s energy declines, and our ability to maintain proper traction with the road decreases. Less traction means a greater chance for a handling issue, especially when superior maneuvering skills are necessary.
The fork oil’s ability to provide damping properties declines because of the following reasons:
- HEAT- Any dirt biker knows to avoid placing their bare hands near their forks or shocks after several spirited laps around the motocross track as those suspension components will get extremely hot. The oil tries its best to dissipate spring energy being released by a spring compressing/decompressing up to seven feet per second.
- SHEARING– Friction from parts moving across each other, including metal components, breaks down the oil and tearing it apart on a molecular level.
- CONTAMINATION- Dirt and moisture work their way into the forks causing the degradation of the fork fluid.
HOW OFTEN SHOULD I REPLACE THE FORK FLUID?
Different motorcycles require different maintenance periods. The application, riding aggressiveness, and style of your motorcycle will help to dictate the actual maintenance schedule. Want to know a great resource and baseline for when you need to replace fork oil? Simply ask M.O.M. (Motorcycle Owner’s Manual)! There are some general guidelines for street riders if a manual isn’t handy:
- Do you see leaking around your fork seal? Good time to replace the fork oil AND seals!
- Sport bike riders, aggressive street riders, riders who tour with excessive weight (including 2-up), and riders who cover rough terrain often (dual-sports), may find major benefits in a fork oil change in as little as 10,000 miles.
- Cruisers and touring bikes may find their maintenance intervals to be much longer – 20,000+ miles.
Again, we recommend verifying the maintenance intervals with M.O.M., but if you have any doubt, the sooner the better. We also prefer visiting a trusted local dealership or experienced repair shop to freshen up your front end. You will receive an immediate benefit in ride plushness and ride safety. Who wouldn’t like that?
Enjoy your comfy ride,
-LUC
DISCLAIMER: THE VIEWS AND OPINIONS EXPRESSED IN THIS COLUMN ARE NOT NECESSARILY THOSE OF ANY MANUFACTURER. THE CONTENT PROVIDED IS MERELY EDUCATIONAL AND NOT INTENDED AS A REPLACEMENT FOR PROFESSIONAL REPAIR. TEAM ARIZONA, ITS STAFF, AND ITS RIDERCOACHES ARE UNAVAILABLE FOR PRIVATE MOTORCYCLE REPAIR; WE RECOMMEND SEEING YOUR LOCAL DEALERSHIP OR REPAIR SHOP.
Oddly enough, the average motorcyclist doesn’t pay much attention to one of the most important systems of the motorcycle: SUSPENSION. Making sure our suspension is operating properly is key to our job as traction managers (also known as motorcyclists). Fork fluid is a key element to keeping the rubber on the road. So what do we need to know about it?
WHAT DOES FORK FLUID (oil) DO?
Simply, the fork fluid helps with the damping properties of the fork, including rebound and compression damping. By damping, we mean the fork oil helps control the spring’s energy by dissipating the spring’s energy into heat. The fork oil accomplishes this mission by being directed through orifices or valving systems. As the fluid rushes through the holes or valves, friction is created and heat is generated.
WHY DO I NEED TO MAINTAIN THE FORK FLUID?
We care about the condition of the fork oil because as the oil ages, it breaks down and its ability to convert the spring’s energy declines, and our ability to maintain proper traction with the road decreases. Less traction means a greater chance for a handling issue, especially when superior maneuvering skills are necessary.
The fork oil’s ability to provide damping properties declines because of the following reasons:
- HEAT- Any dirt biker knows to avoid placing their bare hands near their forks or shocks after several spirited laps around the motocross track as those suspension components will get extremely hot. The oil tries its best to dissipate spring energy being released by a spring compressing/decompressing up to seven feet per second.
- SHEARING– Friction from parts moving across each other, including metal components, breaks down the oil and tearing it apart on a molecular level.
- CONTAMINATION- Dirt and moisture work their way into the forks causing the degradation of the fork fluid.
HOW OFTEN SHOULD I REPLACE THE FORK FLUID?
Different motorcycles require different maintenance periods. The application, riding aggressiveness, and style of your motorcycle will help to dictate the actual maintenance schedule. Want to know a great resource and baseline for when you need to replace fork oil? Simply ask M.O.M. (Motorcycle Owner’s Manual)! There are some general guidelines for street riders if a manual isn’t handy:
- Do you see leaking around your fork seal? Good time to replace the fork oil AND seals!
- Sport bike riders, aggressive street riders, riders who tour with excessive weight (including 2-up), and riders who cover rough terrain often (dual-sports), may find major benefits in a fork oil change in as little as 10,000 miles.
- Cruisers and touring bikes may find their maintenance intervals to be much longer – 20,000+ miles.
Again, we recommend verifying the maintenance intervals with M.O.M., but if you have any doubt, the sooner the better. We also prefer visiting a trusted local dealership or experienced repair shop to freshen up your front end. You will receive an immediate benefit in ride plushness and ride safety. Who wouldn’t like that?
Enjoy your comfy ride,
-LUC
