5.2  Showa

     Honda TRAC Anti-Dive Brakes (all)

     Torque Reactive Anti-Dive Control
     1982-2000

Identify your Fork Type

There are 4 different styles of TRAC Anti-Dive that I am aware of with many subtle variations.

5.2.1 TRAC on the left leg only. Standard Rod on the right.
5.2.2 TRAC on the left leg only. Standard Rod with Rebound Adjustment on the right.
5.2.3 TRAC on both legs. No Rebound Adjustment on both legs.
5.2.4 TRAC on both legs. Rebound Adjustment on both legs.

5.2.1 TRAC on the left leg only. Standard Rod right.

    No Adjustable Rebound

    No Brazing

    37mm

    FEGV S3501

    CBR600 1987-90 Style

1.1 Identify your Hardware

The Anti-Dive leg has different hardware than the Standard leg. This includes the fork tube itself. When disassembling keep all parts of each leg separate. Keep in mind that many of these older bikes have been taken apart before and are mixed up. See the images below to identify the correct pairing of the hardware.

The Anti-Dive Leg does not have a bottoming cone. You will be leaving the Anti-Dive Check Valve Hardware off.

1.2 Anti-Dive Rod Modification

The stock Anti-Dive damping rod has Check Valve hardware on it consisting of clips, washers and a spring. Remove the Anti-Dive Check Valve hardware and discard. This will disable the Anti-dive.

Anti-Dive Rod - Drill (4) 8mm (5/16") compression feed holes starting 10mm above the existing holes at 90 degrees to the original holes. Drill a second set of holes 10mm above the first new set also at 90 degrees. Deburr the holes inside and out.

Note - when drilling the compression holes you may end up drilling one set of holes at or thru the top clip grove in the damping rod, this is fine.

If there is a bottoming cone on this leg the new compression feed holes should be located above the top of the bottoming cone.

No Bottoming Cone Version 1987 CBR600F

Bottoming Cone on Anti-Dive Leg Version 1984-86 VF500F, 1983 VF750C/S, 1984 VF700C/F, 1985 VF700S, 1983 CB1000C

1.3 Standard Rod Modification

Standard Rod - Drill (4) 8mm (5/16") compression feed holes starting 10mm above the circlip groove. Drill a second set of holes 10mm above the first new set at 90 degrees. Deburr all new holes inside and out.

1.5 Ready to Assemble

Install the top-out spring on the damping rod first. Then insert the damping rod into the correct fork tube.

On the Standard Leg install the circlip that retains the bottoming cone then install the bottoming cone.

This image includes the outer fork legs. Note the external Anti-Dive valve on the right. You do not need to modify the TRAC Valve itself.

Flat-Top Damping Rods require an adapter. Cupped-Top does not.

Be sure to setup the Emulator valving and fork spring preload according to the DVS Setup Sheet. Install the recommended fork oil. See Standard Emulator Instructions.

5.2.2 TRAC on the left leg only. Standard Rod with Adjustable Rebound right.

    No Brazing

    1 Emulator

    39, 41mm

    FEGV S3803, FEGV S4106

    VF700F 1984-85, VF750F 1983-84, VF1000 1984-86 Style

This style uses just one Emulator on the TRAC side only. The Rebound leg is left stock.

2.1 Anti-Dive Rod Modification

The stock Anti-Dive damping rod has Check Valve hardware consisting of clips, a washer, a spring and a sleeve washer. Remove the Anti-Dive Check Valve Hardware and discard. This will disable the Anti-dive.

Drill (4) 8mm (5/16") compression feed holes starting 10mm above the existing holes at 90 degrees to the original holes. Drill a second set of holes 10mm above the first new set also at 90 degrees.

Deburr the holes inside and out.

Note - when drilling the compression holes you may end up drilling one set of holes at or thru the top clip grove in the damping rod, this is fine.

If there is a bottoming cone on this leg the new compression feed holes should be located above the top of the bottoming cone.

2.2 Standard Rod with Rebound Adjust - No Modification
 

You do not need to make any modifications to this leg. However, if you would like to rebuild it this is a good time.

The right leg has a rebound control rod coming down from the fork cap. The control rod is D-shaped and connects to a plate that, in turn, connects to a sleeve. The sleeve has a notch that lines up with a different size rebound hole depending on the adjuster selection. You will not be disassembling it but here is what it looks like inside.

1984-86 VF1000F Style Bottoming Cone - requires o-ring

2.3 Assembly of the Rebound Adjuster Leg

Notice that the bottoming cone and the damping rod are indexed with a flat on the damping rod. The "D" shaped notch in the bottoming cone must line up.

Also the "V" on the outside of the bottoming cone must line up inside the fork slider.

If these forks have ever been taken apart it is likely that either or both of these are damaged from previous incorrect assembly and may require repair.

2.4 Ready to Assemble
 

Flat-Top Damping Rods require an adapter. Cupped-Top does not.

Be sure to setup the Emulator valving and fork spring preload according to the DVS Setup Sheet. Install the recommended fork oil. See Standard Emulator Instructions.

5.2.3 TRAC on Both Legs

    No Adjustable Rebound

    No Brazing

    41mm

    FEGV S4104

    GL1500 1988-2000 Style

3.1 Identify your Hardware

The two legs are identical except only one has a bottom-out cone. It doesn't matter which one.

3.2 No Bottom-Out Cone Rod Modification

Remove the Anti-Dive Check Valve Hardware and discard. This will disable the Anti-dive.

The side without the Bottom-Out Cone only needs two holes added. Drill (2) 8mm (5/16") compression feed holes in the location shown. This means one hole through both sides. The reason this one only needs 2 holes is the 4 original holes are already large.

Deburr the holes inside and out.

3.3 Bottom-Out Cone Rod Modification

Drill (6) 8mm (5/16") compression feed holes starting 6mm above the top circlip groove (3 sets of 2 holes). Drill two more sets of holes in 10mm increments above the first set at 90 degrees.

This will disable the Anti-Dive.

Deburr the holes inside and out.

Because the Bottom-Out Cone is located ABOVE the Anti-Dive Check Valve this hardware will remain as shown. If it is not installed the Bottom-Out Cone will not work.

There is more than one version. Some models have the Bottom-Out Cone located BELOW the Anti-Dive Check hardware. In that case the Check Valve hardware will be removed.

3.4 Ready to Assemble

On this particular design the top-out springs are pressed on the damping rod. If yours are loose install them before inserting the damping rod into the fork tube.

Flat-Top Damping Rods require an adapter. Cupped-Top does not.

Be sure to setup the Emulator valving and fork spring preload according to the DVS Setup Sheet. Install the recommended fork oil. See Standard Emulator Instructions.

5.2.4 TRAC and Adjustable Rebound on Both Legs

    Brazing Required

    39mm

    FEGV S3801

    CB1100F 1983 Style

4.1 This is a difficult modification that requires brazing. We recommend this work be performed at Race Tech.

In this modification the external rebound adjusters will be disabled.

4.2 Disassemble the rebound adjuster mechanism at the top of the rod.

Pry the cap out of the damping rod and discard.

 4.3 Remove the circlip and discard.   

4.4 Remove the adjuster components from inside the damping rod including the adjuster sleeve and discard them. Leave the inside of the damping rod gutted.

Remove and discard the long inner tube if your model has one.

4.5 The tricky part - Braze the rebound holes (near the top of the rod). Leave  the single smallest rebound damping hole intact. This is the equavilent of running it on #3.

This image is not from this bike but it shows what a brazed hole should look like. The plug to the left is larger because of the original chamfer.

4.6 The "D" shaped rod will need to be cut off near the cap.

This picture is not from this bike but you get the idea.

4.7 Enlarge Compression Feed Holes

The stock damping rod has Check Valve hardware consisting of clips, a washer, a spring and a sleeve washer. Remove the Anti-Dive Check Valve Hardware and discard. This will disable the Anti-Dive.

Drill (4) 8mm (5/16") compression feed holes starting 10mm above the existing holes at 90 degrees to the original holes. Drill a second set of holes 10mm above the first new set also at 90 degrees.

Deburr the holes inside and out.

Note - when drilling the compression holes you may end up drilling one set of holes at or thru the top clip grove in the damping rod, this is fine.

If there is a bottoming cone on this leg the new compression feed holes should be located above the top of the bottoming cone.

1983 CB1100F Bottoming Cone - same idea
O-ring on OD of bottoming cone required

4.8 Assembly

Notice that the bottoming cone and the damping rod are indexed with a flat on the damping rod. The "D" shaped notch in the bottoming cone must line up.

Also the "V" on the outside of the bottoming cone must line up inside the fork slider.

If these forks have ever been taken apart it is likely that either or both of these are damaged from previous incorrect assembly and may require repair.

4.9 Ready to Assemble

Install the Top-Out Spring before inserting the damping rod into the fork tube.

Flat-Top Damping Rods require an adapter. Cupped-Top does not.

Be sure to setup the Emulator valving and fork spring preload according to the DVS Setup Sheet. Install the recommended fork oil. See Standard Emulator Instructions.