Showa SFF TAC Fork

 

Adjusting the Showa SFF TAC Fork

 

Check the air pressure of the fork before every ride.  Adjust the fork pressure with the bike on a stand so the front wheel is off the ground.  Use a high pressure air fork pump rated between 0 and 300 psi to adjust the air pressure in the order of inner chamber, outer chamber and balance chamber.  Do not use air from a compressor to fill the fork (it might contain traces of moisture which will wreck the internals).  When you remove your pressure gauge from the fork a small amount of air will be lost from the chambers.  The amount of air loss is not a big factor on the inner and outer chambers, but it can be significant on the balance chamber where it can affect the setting by as much as 15 psi.  To determine, how much air loss you are experiencing, remove and reinstall your pump several times to determine the exact amount of loss and add that extra amount to the balance chamber each time you adjust the air pressure.

 

 

Tuning

 

Start by adjusting your fork's air pressure to the standard air pressure and set your clickers to the standard damper settings.  Changes to the clicker settings have more effect than with a conventional fork because of the stiff valving in the single damper.  Make inner chamber air pressure changes in 7 to 14 psi increments.  If you want a stiffer spring, add air to the inner and/or outer chamber.  Reduce air pressure in the inner and/or outer chamber to make the spring softer.  The spring rate can also be tuned to be more progressive by adding oil to the outer air chamber.  Removing oil from the outer air chamber will make the air spring have a more linear rate.

 

The pressure of the balance chamber should not exceed the inner chamber.  Adding more pressure to the balance chamber will make the fork plusher but will pull the front end down and lower the ride height.  Reducing air in the balance chamber will make the fork stiffer initially and make the front end ride higher.  The key is to find the proper balance.

 

Troubleshooting Symptoms

TOO Soft

*Increase air in the inner chamber if too soft overall

*Increase air in the outer chamber if too soft overall

*Decrease air in the balnce chamber if too soft initially

*Increase compression damping

*Note; Increase rebound damping whenever you increase inner or outer air pressure

 

TOO Stiff

*Decrease air in the inner chamber if too stiff overall

*Decrease air in the outer chamber if too stiff overall

*Increase air in the balnce chamber if too stiff initially

*Note; Decrease rebound damping whenever you decrease inner or outer air pressure

 

Bottoming

*Add fork oil to damping chamber

*Increase outer chamber air pressure

*Increase Compression damping

 

Low Ride Height

*Decrease pressure in the balance chamber

*Increase compression damping

*Decrease rebound damping

 

High Ride Height

*Increase pressure in the balance chamber

*Decrease compression damping

*Increase rebound damping