Seems to me that a lot of people are rollin’ on what could be called “Performance Harleys,” bikes that have been modified from stock to be ridden at high speed for extended periods of time. Not that anyone out there rides faster than the speed limit of course, but bikes that are meant to really work for that style of riding. Harleys have never really been a “Performance handling bike” so to say. They work, but the suspensions have never been up to par with what they could be. The performance Harleys that I am referring to are mainly Dynas and FXRs, but can extend for sure to XLs. The 39mm Showa forks on these bikes are a decent fork, if you have the FXDX or Sportster sport fork you have adjusters built in, but, as is the stock 39mm fork needs a little work. I have always recommended a progressive wound fork spring and heavier oil for these forks as well as the various damper modifications out there to really get them where they need to be a suitable fork.
Speed Merchant has come up with another way to add a bit of adjustability to your tuned 39mm fork. These fork adjusters are the final piece of the puzzle to allow you to adjust your spring preload without pulling the top caps off. They are super easy to install and we are going to show you just how they go in.
STEP 1: First off you need to disconnect the ground to your battery; you should always do this to make sure that the bike can’t be started while the wheel is off the ground. Raise the front wheel off the ground to unload the spring tension on the fork. You never want to pull a fork cap off the bike with the wheel sitting on the ground, it’s a real easy way to collapse your forks and drop your bike.
STEP 2: Loosen your upper fork tree pinch bolts. Sometimes they can make the cap hard to get off, and then remove the stock fork caps. They have a 1 3/8-inch hex on them and when you get them almost off make sure that you have your hand cupped over them as they might want to fly off when they last thread is released.
STEP 3: Ok you now have the caps off. This is where you need to do some homework! If you take them off and find just a spring underneath, you have stock springs and probably stock everything in there, go to step seven. But if you take them off and find any sort of spacer (PVC, metal, stacked washers, whatever) you need to make some decisions. If you have spacers in your fork you probably have some aftermarket springs in there. If you are essentially happy with your frontend feel then I suggest shortening your spacer so when you install the adjuster you will have equal adjustment up and also down. It’s this kind of fine-tuning that can make all the difference. Yes it’s hard to believe that � inch of adjustment will even make a difference but it totally does. This would mean taking � inch off the installed spacer. When you shorten it this way it makes it so when the adjuster is right in the middle of its travel, it’s right where it was when you started. If you just want the adjuster to make it stif
STEP 4: Make sure that your Speed Merchant adjuster is backed off, so it puts the least pressure on the supplied spacer and drop the supplied spacers on top of the spring and install the new top caps. If you have aftermarket springs etc in your fork you might have more preload than stock. Just take your time and be careful. Remember to retighten those pinch bolts on your top clamp when the new caps have been installed.
STEP 6: If you have stock springs, take the bike off the lift and put the front wheel on the ground. If you have aftermarket springs or other internals, go ahead and adjust the SM adjusters down seven and a half full turns. That will put you basically where you started. Then take the bike off the lift.
STEP 7: Ride your bike as you would normally and adjust the forks to where you are happiest with the ride. Simple right? Many people might doubt the difference � inch of spring pressure can make, but believe me, it does.