Front Suspension

Most of this article will be basic, but I will cover a few points that you normally will not see or be told about anywhere else.   We will start with some basic maintenance.  Get out your service manual.  The manual will give you the bolts and nuts of how to do the basic tear down.  Before you start, measure the height of the fork tube that is above the top of the upper triple clamp and write this measurement down.

If you have a new bike, have the fork oil height checked and have any corrections made if needed.  If you just bought a used cycle, get a suspension shop to service the forks and replace the seals and wipers.  If you have a cycle that has over 5 months riding time on it, have a shop service the forks.  Set the clickers to stock settings. Basic fork oil change should be performed at least every 6 months.

Next, remove the upper and lower triple clamps and inspect the upper and lower bearings and races for wear or pitting.  Grease and reinstall, or replace, depending on condition.  This service should be performed when you first get the cycle and once a year thereafter.  Reinstall the triple clamps and adjust the tension on the bearings.  Check your service manual for the proper tension.

This next step is VERY IMPORTANT.  This is the PROPER WAY to install forks.  ATTENTION – if improperly installed, the forks can’t work to their full potential.  First install the left fork (left is determined as if you were sitting on the bike) into the triple clamps.   (A little WD 40 sprayed on the fork tubes will make them slide in easier.)  The measurement you took before you removed the forks will allow you to re-install the left fork at the proper height.  VERY IMPORTANT – Torque the pinch bolts to factory specs.  Next, install the right fork in the triple clamp at approximately the same height as the left fork and LIGHTLY tighten ONLY ONE of the pinch bolts.  This next step is CRITICAL –install the axle into the forks, grab the axle between the left and right fork, and begin rotating the axle.  As you rotate the axle, loosen the pinch bolt on the right fork and move the right fork up and down until you locate the place where the axle turns most freely.   Now, at this position, torque the pinch bolts to factory specs.  Install the wheel and brakes, and tighten the axle and/or axle nut.  Torque the axle pinch bolts on the LEFT FORK ONLY.  Now, you need to work the forks up and down.  The best way is to tie the cycle down in/on your trailer, or ride the cycle SLOWLY up and down the driveway, and pump the front brake level several times, making the forks move deep into the travel.  Now you can TORQUE the RIGHT axle pinch bolts.

The last step for the forks is to check race sag.  Most manuals and articles never mention front race sag, but it is important.  With the cycle on a stand and the wheels off the ground, wrap a piece of duct tape around the brake hose such that the top of the duct tape is even with the bottom of the brake hose guide.  Take the cycle off the stand, mount the cycle, and bounce up and down while you hold the front brake.  Then sit down with your shoulders over the handlebars and your hips over the foot pegs.  Now, look at the tape on the brake hose.  The bottom of the tape should be between the bottom and the top of the guide.  In this position, you will have the recommended race sag of 2 to 2 1/2 inches.  If the tape is not between the top and bottom of the guide, changes need to be made.  If the bottom of the tape is above the top of the guide, you need heavier springs.  If the bottom of the tape is below the bottom of the guide, you need softer springs.

Within the three columns we have now covered the front and back of the cycle.  Everything should have been  serviced, and you should have good bearings, proper springs, sags properly set, and fresh oil.  Next month we will learn how to adjust the suspension to make what you have work the best it can for you.