Fork Spring Preload Moves While On Track?
Posted by Kenny Martin on 8th Jun 2022
If you’ve ever walked through a paddock on a race weekend, you might have seen motorcycles with marks on their fork caps. These marks, usually a straight line across the preload adjuster and housing, made with a black sharpie, are to indicate to a tuner or rider that the preload adjuster has moved while out on track. When the motorcycle returns to the paddock a rider or tuner will re-align the sharpie marks to maintain the correct preload.
Most all fork caps experience this rotation due to vibration and natural frequency of the parts. This issue is mostly noticeable on older sets of fork caps where friction between parts have become less due to age. Sealing O-rings might have dried a little and shrunk. Clamp force wear between parts along with part tolerances have probably increased which allows the adjusters to move. Normal maintenance or repair on fork caps can correct this issue and our technicians will be happy to rebuild your fork caps if you experience this issue.
Those who do not have quick access to rebuild parts, a proper suspension technician locally, or the know how to do a rebuild yourself (it does require some expensive special tools), our preload lock may be the correct tool for you. Our preload lock prevents the hassle of grabbing a tool each time you return to your pit stall. These locks, made for aftermarket fork cartridges, lock external preload adjusters in place. This prevents the adjuster from rotating on its own, changing preload while on track, and keeping your optimal setting locked in place.
Our preload lock is simple to use and easy to install. Once you have finished tuning your suspension to your liking and have settled on external preload adjustment it is time to install the lock. Slide the lock halfway on preload adjustment nut, rotate the adjuster to the nearest lock position and then slide the lock down to lock preload in place. Once the lock is fully seated, tighten the set screw, which I might add, is a flat top set screw so it won’t dig into the aluminum adjuster and leave those nasty “o” marks, then you’re done!
During a race you will no longer have to working about your preload changing during your event. These locks work great for longer 25min races or endurance races