Gregory Bender

Disc brake - installing FAC dampers into original disc brake forks

Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models

Updated:

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Thanks to Tom Halchuk for sending me this information in a personal e-mail. In Tom's own words:

These are the procedures for updating a disc brake Eldorado to an FAC front suspension. Use these procedures if you plan on going through the trouble of upgrading the stock dampers/springs to FAC dampers and progressive springs.

Read the complete set of procedures to put your mind at ease about this upgrade.

Parts were purchased at MG Cycle

One note before we start. There will be about a 38 inch increase in length to the stock setup. The difference is the height of the hex head on the FAC cap. No big deal.

Parts needed:

Here we go:

  1. The FAC damper schrader valve will be removed.
  2. The FAC damper is going to have the outer threads and the hex milled off to the same diameter as the damper.
    Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.
    Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.

    Photo courtesy of Tom Halchuk.

    Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.
    Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.

    Photo courtesy of Tom Halchuk.

  3. A stock drum style cap will be center drilled (no more than 12 inch deep) and taped on the bottom to the same thread as the schrader 8 mm × 1.25 mm. Run the same tap into the freshly milled FAC top as well.
    Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.
    Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.

    Photo courtesy of Tom Halchuk.

  4. The 80 mm × 8 mm × 1.25 mm bolt is cut into 1 inch studs. The stud is installed with red Loctite into the Drum Style top. Blue Loctite is used on the FAC aluminum top.
    Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.
    Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.

    Photo courtesy of Tom Halchuk.

  5. Insert the fork tubes into the triple tree. Make sure the tube is fully inserted into the upper triple tree. Tighten the lower triple to hold tubes in place.
  6. Assemble the FAC damper to spring with cups and circlip
  7. Install fork seals
  8. Install FAC assembly into the lower fork leg.
  9. Fill lower leg with 160 cc fork oil/ATF fluid.
  10. Insert lower fork leg onto appropriate tube. Eagle should be pointed forward.
  11. Push lower leg up until the FAC assembly sticks out.
  12. Hold the top of FAC assembly with vice grips. Use blue Loctite on the FAC top threads. Attach steel drum cap and washer to FAC unit.
    Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.
    Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.

    Photo courtesy of Tom Halchuk.

  13. Lower the leg.
  14. Tighten the assembly to the fork tube. Loosen lower leg and re-tighten top cap.
  15. Repeat for the other side
  16. When both sides are installed. Insert mounting dampers for instrument panel.

Thanks to Jim Carey for posting this information on the Yahoo! Loopframe_Guzzi news group. In Jim's own words:

I have followed the excellent articles in Gregory Benders site for fitting FAC dampers to the Eldo disc forks. I made one change, used the stock Eldo fork top caps and modified them to fit the FAC dampers rather than use the drum brake Eldo top plugs. Just need to cut down the stock Eldo disc caps. Some machining required to match the same depth as the brake drum fork caps.

I also turned down about 3 mm off the top of the FAC unit to bring the overall fork length down to closely match stock.

I used Cycle Gardens second disc carrier on the left side and new floater discs and calipers from MG Cycle. Just waiting on brake line kits to finish it off.

Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.
Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.

Photo courtesy of Jim Carey.

Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.
Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.

Photo courtesy of Jim Carey.

Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.
Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.

Photo courtesy of Jim Carey.

Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.
Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.

Photo courtesy of Jim Carey.

Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.
Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.

Photo courtesy of Jim Carey.

Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.
Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.

Photo courtesy of Jim Carey.

Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.
Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.

Photo courtesy of Jim Carey.

Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.
Installing FAC dampers into original disc brakes as used on some Moto Guzzi Eldorado models.

Photo courtesy of Jim Carey.