Anti-Dive opinions...

[Tor-King]

I am amidst rebuilding the forks on my '86.  Of course it has the anti-dive system; the system that NEVER worked from the factory but a great gimmick.  Here
are my questions:
1. Keep the unsightly things or cap them off?
2.  Since I have everything dismantled, are there any internal fork components that will require "tweaking" to accept blocking plates?
3.  Are the '84, '85 forks the same as the '86 (I am sure they are but I thought I would ask to be 100% certain)? The reason I ask is I found a source in Canada that makes blocking plates but he has them listed for FJ1100...

And...no, I am not looking for '89+ forks to replace these, especially after all the time spent polishing the lowers (Pat would be proud).

Dean

[FJmonkey]

Dean, there is a reason the AD tech did not continue forward into future gen bikes. That said, the least expensive option is take the top half off and bin/shelf it. Remove the extra brake lines. Flip the bottom half, reinstall and deal with 16" wheels. Beyond that is upgrading your forks and all hell could break loose from 89'+ to USD forks that get the chicks.

[racerrad8]

The part numbers for the lower fork legs for 84-87 are identical so I would presume they are the same through out the anti dive years.

Robert

[fj1289]

Remember - blocking plates can't just be a flat plate - they need a bypass machines in them to allow fork oil to pass to maintain proper fork function (if you don't mount the lowers as FJmonkey posted)

[Alf]

With a good brake master cylinder, good brake hoses, Hagon springs and 10-40 motor oil the front fork work wonderfully even for aggressive riding. Even the brakes have good feeling and stooping power with Summimoto OE pads. I don't see the necessity of removing the AD units

[FeralRdr]

Dean, there is a reason the AD tech did not continue forward into future gen bikes. That said, the least expensive option is take the top half off and bin/shelf it. Remove the extra brake lines. Flip the bottom half, reinstall and deal with 16" wheels. Beyond that is upgrading your forks and all hell could break loose from 89'+ to USD forks that get the chicks.

If I might ask, why flip the bottom half.  When I disabled my AD units, I just removed the lower brake lines, and put an appropriate sized bolt in the Banjo Bolt port.  I never encountered any issues just doing that. 

Of course, I also upgraded to heavier fork springs and eventually, increased the amount, and viscosity of the fork oil to "dial in" the suspension.   However, even with a lesser weight and amount of oil, the forks still functioned well with just the lower lines removed.

[FJmonkey]

Flipping them over is just cosmetic.

[FeralRdr]

Oh you fashionista! 

[Tor-King]

If I was to keep the AD units (for purely cosmetic and originality reasons), will it matter if they are seized?  In other words, will "inoperable" units effect the suspension function?  Can these systems be "worked" on?
Dean

[FJmonkey]

Once you disconnect the brake lines they are just weight...

[FJ_Hooligan]

Remember - blocking plates can't just be a flat plate - they need a bypass machines in them to allow fork oil to pass to maintain proper fork function (if you don't mount the lowers as FJmonkey posted)

You can use a flat (undrilled) blocking plate IF you drill at least 2 ~5/16" holes in the damper rod just ABOVE the "step" that locates the tapered spindle.

[mr blackstock]

G'day,

It looks like there might be info in this chat that I might need... The anti-dive units on my '85 were seized up, so I just removed the brake hose and left them.  I am unaware if oil is able to pass between the fork holes.  I did consider blocking plates, but the cost of purchasing I thought was high, but I can make a set, just without the groove passage.

Drilling holes in the damper rod?  Is this a good solution?  We are talking about the rods that go all the way down into the fork, and have to fit in that bloody annoying little hole after 5 minutes of struggling?

I would be keen to hear how well the modification works..

cheers, Gareth

[FJ_Hooligan]

That's the damping adjuster rod.  The damper rod is what the allen bolt on the bottom of the fork slider is holding in place.  It's also the main oil flow controller when the fork is moving.  I used to know how the oil flow and the anti-dive all worked together, but since I did away with all that about 17 years ago, I've forgotten the specifics. 

I recall the a/d unit uses 2 opposing springs on the tapered valve to control oil flow.  One spring is preloaded by the hi/low adjustment.  The other spring is compressed by a small piston activated by brake line pressure.  The brake pressure tries to close the a/d valve and is opposed by force from the adjustment spring.  Adjusting the a/d to High removes preload from the opposing spring thus allowing the brake pressure spring to close the valve more easily and restricting flow to stop/slow fork dive.  In the Low position, the opposing spring has a higher preload which keeps the valve open and allows the fork to compress more easily.

I do remember the RaceTech emulator instructions were to drill 4 additional holes above the step on the damper rod to disable any existing damping control so the emulator would be the only thing affecting flow.  I believe you are also supposed to braze/glue/block the rebound holes in the damper rod.  I thought Randy's valves also included drilling the damper rod but I don't recall. 

Drilling additional holes In the DR by-passes the a/d circuit

[Pat Conlon]

Hooli has forgotten more than I know.......sigh....

[fj1289]

With a good brake master cylinder, good brake hoses, Hagon springs and 10-40 motor oil the front fork work wonderfully even for aggressive riding. Even the brakes have good feeling and stooping power with Summimoto OE pads. I don't see the necessity of removing the AD units

10-40 weight?!  That sounds like another way to disable the anti-dive function!