Instructions for Adding Fork Oil to Storz/Ceriani Inverted Forks
  1. Place the bike on a stand or lift to take all of the weight off of the front wheel.
  2. Loosen the fork tube pinch bolts on the upper triple tree only.
  3. Remove the chrome trim buttons using your fingernail. This will expose two shallow holes for a pin spanner tool (our p/n FT5481A1) to unscrew the top cap.
  4. Use a piece of thin cloth between the pin spanner and the top cap to prevent scratches. Unscrew just one top cap at a time. NOTE: The top cap is attached to a cartridge rod so it will not come completely off when you unscrew it (see photo).
  5. Slowly lower the bike off the stand allowing the weight of the bike to push on the the fork leg that is still assembled. This will expose the fork spring and the cartridge rod on the fork leg that you unscrewed the top cap from. Carefully pour the fork oil between the fork spring and cartridge rod.
  6. Place the bike back on the stand to remove the weight from the front wheel. This will allow you to screw the top cap plug back into the fork leg. Repeat the process for the opposite fork leg. Tighten the pinch bolts on the upper triple tree when you are finished.

Oil Quantities and Type of Fork Oil

To drain fork oil, unscrew the drain screws found of the backside of the lower fork leg near the front axle. Due to the internal cartridge design, a significant amount of oil will remain in the fork after the drain screws have been removed. To properly drain the fork oil, it will be necessary to pump the front forks several times, then allow the bike to sit and slowly drain. It may be necessary to repeat the process several times.

You must use lightweight Cartridge Fork oil, we recommend Golden Spectro GS85/150 which is approximately 3W viscosity. Do NOT use fork oils for conventional H-D forks.

Refill Quantity: 420cc each leg for 31/32" length fork, 490cc for 33/34" length fork

NOTE: If you find the fork is too soft and bottoms out easily, you can add 50cc to each leg quantity. This will decrease the air space inside the fork and effectively increase the spring rate.


Instructions for Changing Oil Seals on Storz/Ceriani 55mm Inverted Forks

  1. Drain the fork oil from each leg by removing the drain screws and pumping each leg until empty. Loosen the (4) pinch bolts on the upper tree only. Use a pin spanner tool (our p/n FT6481A1) with a soft thin cloth to prevent scratches and just loosen the top cap on each leg. Remove the front wheel and fender, and then remove the individual fork legs from the triple trees.
  2. Hold the exposed section of the steel fork tube (45mm diameter) carefully in a vise using aluminum soft jaws.
  3. Loosen the pinch bolt at the top of the lower leg (or set screw on later forks) that helps lock the lower leg onto the steel tube.
  4. The lower legs are threaded onto the steel tubes with a normal right hand thread. Insert the front axle into the lower leg and use it a wrench to unscrew the lower leg from the steel tube. It may be necessary in some cases to slightly warm the lower leg with a heat gun to aid in removing the lower leg.
  5. Remove the threaded cap at the top of the fork tube using a pin spanner and a soft thin cloth to prevent scratches to the cap. This will expose the fork spring and cartridge rod. Loosen the jam nut located on the cartridge rod and unscrew the top cap from the cartridge rod. The complete cartridge and spring assembly can be removed from the bottom of the steel fork tube. NOTE: It is not necessary to dis-assemble the cartridge unit or remove the fork spring from the cartridge rod.
  6. Carefully remove the dust seal (or dust cover on V-Rod forks) from the upper fork tube. Then remove the wire retaining ring located just above the fork seal.
  7. Hold the upper tube securely and use a slide hammer motion with the steel tube to drive out the fork bushing, spacer washer, and oil seal.
  8. Clean the fork tubes and re-install the guide bushing into the upper fork tube. Assemble the steel fork tube into the aluminum tube using a small amount of fork oil on sliding surfaces. Slide the fork seal spacer washer over the steel tube; it will rest against the guide bushing in the upper tube.
  9. Use a thin packing tape to cover the threaded area of the fork tube. This will prevent the threads from tearing the new oil seal during installation. Use a seal driver to drive the seal into place against the spacer washer. Now install the wire circlip to retain the fork seal.
  10. Remove the packing tape that was used to protect the threaded area of the steel fork tube. Re-install the cartridge assembly with fork spring in place.
  11. Make sure the threads are clean and re-install the lower leg using a small amount of Loctite 565 Teflon pipe thread sealant on the threads of the steel tube. Tighten the set screw or pinch bolt on the lower leg.
  12. Re-install the top caps and tighten them against the jam nut (and spacer, if used) on the cartridge rod. Add fork oil, 420cc each leg. We recommend Golden Spectro GS85/150 (3w) fork oil.


Instructions for Changing Oil seals on GCB 54mm Inverted Forks

  1. 1) Drain oil from each fork leg by removing the drain screws and pumping each leg until empty. Loosen the (4) pinch bolts on the upper triple tree only. Use a pin spanner tool (Storz p/n FT6481A1) with a soft thin cloth to prevent scratches and just loosen the top cap on each fork leg. Remove the front wheel and fender, then remove the individual fork legs from the triple trees.
  2. Hold the exposed section of the steel fork tube (43mm diameter) carefully in a vice using aluminum soft jaws to prevent scratches.
  3. Loosen the pinch bolt at the top of the lower leg that helps lock the lower leg onto the steel tube.
  4. The lower legs are threaded onto the steel tube with a normal right hand thread. Insert the front axle into the lower leg and use it to unscrew the lower leg from the steel tube. It may be necessary to slightly warm the lower leg with a heat gun to help remove it.
  5. Unscrew the threaded seal holder from the upper aluminum tube using spanner tool (Storz p/n FT4354). The dust seal can be removed with your fingers. The oil seal is located on the opposite side of the seal holder. Remove the wire retaining ring and spacer washer (if present). Place the seal holder on a soft piece of wood covered with a cloth and drive the old oil seal out of the seal holder using a screwdriver or similar tool. Press the new oil seal into the seal holder with the spring side of the seal facing you. Reassemble the spacer, retaining ring, and dust seal. Put some thin packing tape over the fork tube threads to protect the new oil seal and reinstall the oil seal holder.

    If you intend to replace the fork bushings also, proceed as indicated.

  6. Remove the threaded cap at the top of the fork tube using the pin spanner and a soft piece of cloth to prevent scratches. This will expose the fork spring and cartridge rod. Loosen the jam nut on the cartridge nut and remove the top cap from the cartridge rod. The complete cartridge and spring assembly can be removed from the bottom of the steel fork tube. NOTE: It is not necessary or advisable to disassemble the cartridge unit.
  7. You can now remove the steel tube by pulling it out from the bottom of the upper aluminum tube. Pull on the steel tube in a slide hammer motion. This will force the lower guide bushing out from the upper tube. The upper bushing is located on the top of the steel tube and can be removed by carefully expanding it and sliding it off of the tube. Install the new bushings and reassemble the fork in reverse order.
  8. When you are ready to reinstall the lower legs, use a small amount of Loctite 565 Teflon Pipe Thread Sealant on the threaded portion of the steel tubes.


Storz Performance, Inc.
239 South Olive Street - Ventura, CA 93001
Phone 805-641-9540   Fax 805-641-3650

The names STORZ ® and CERIANI ® are registered trademarks of Storz Performance, Inc. Any other product names in this catalog are the property of their respective holders. Contents of this catalog are Copyright 2012 by Storz Performance, Inc. All rights reserved, including the right to reproduce this catalog or portions thereof in any means electronic or mechanical without prior written permission from Storz Performance, Inc.