Eliminate Anti-Dive?

[86FJNJ]

I need to do the front brakes. I see RPM sells a front brake line kit that eliminates the anti-dive. That would be my preferred approach since I don't care to have anti-dive, but is there anything special I need to do during this conversion or do I just take off the old and install the new and put some bolts to block off unused anti-dive areas?

Is there a reason I should want to keep the anti-dive?

1986 FJ sat for 15 years so all the front brake lines are trash and need to be replaced.

[Pat Conlon]

In my opinion, my '84's anti dive was ineffective and oem springs too soft. I remedied that by converting over to 1989 forks with heavier springs and emulators....then later going to USD's.

If I were to keep my oem anti dive forks, I would have used these block off plates:

https://www.fastfromthepast.com/dadbpp-rz5b

It's not as simple as bolting a solid chunk of aluminum in place of  the anti dive valves, you need a fork fluid bypass so the damper rod still functions.

[86FJNJ]

Thanks Pat. So, which is less work/ less $? To do brakes keeping anti-dive or eliminate anti-dive with those block off plates you suggest? This is a bike I plan to just use locally on back farm roads for calm riding, no fancy riding...so the option that is less work and/or less $ is more attractive to me.

If I buy new forks from a year without anti-dive then I need to change the front wheel out to match too right?

[fj1289]

Maybe in the files section - but I recall reading you can remove the brake lines from the anti dive units, then flip the anti dive units upside down and bolt them back on instead of buying block off plates.   

[86FJNJ]

thanks for the suggestion but I didn't see anything like that in the files section. If eliminating the anti-dive is just a matter of ordering the brake kit from RPM without anti-dive and then installing those blocks that Pat suggested that seems easy enough, is that all it is?

[aviationfred]

In my opinion, my '84's anti dive was ineffective and oem springs too soft. I remedied that by converting over to 1989 forks with heavier springs and emulators....then later going to USD's.

If I were to keep my oem anti dive forks, I would have used these block off plates:

https://www.fastfromthepast.com/dadbpp-rz5b

It's not as simple as bolting a solid chunk of aluminum in place of  the anti dive valves, you need a fork fluid bypass so the damper rod still functions.

I suggest the blanking plates that Pat has listed.
I have done a cost analysis for a 1989/1990 FJ1200 fork and wheel install. Even using used parts from eBay. Expect the cost of parts to be in the $1000.00 range.


Fred

[Pat Conlon]

Thanks Pat. So, which is less work/ less $? To do brakes keeping anti-dive or eliminate anti-dive with those block off plates you suggest? This is a bike I plan to just use locally on back farm roads for calm riding, no fancy riding...so the option that is less work and/or less $ is more attractive to me.

If I buy new forks from a year without anti-dive then I need to change the front wheel out to match too right?

Chris (fj1289) mentioned something that I now remember, although I've not done this myself...I recall FJMonkey Mark also mentioned this...

Remove the brake line from the anti dive (AD) valve and flip the valve over so the adjusting nut is now on the top. Folks who have tried this say it works.

This should be the cheapest way to defeat the AD valves.

You can reuse the single line banjo fittings from the AD valves on your brake calipers (don't forget fresh crush washers) In the slim case you ever wanted to reuse the AD valves, seal or plug the opening (M10x1.25) where the banjo fitting threaded in the AD valve. This will keep out any dirt or road grime.
You should be good to go....

Save your money and effort for some real cartridge forks in the future.
If you ever decide to convert over to non AD forks, like the '89-95 FJ forks, you will be rewarded with a lighter 17" front rim, lighter rotors, and the ability to directly bolt on the superior Yamaha 4 piston monoblock brake calipers.
Late model FJ forks with RPM springs, valves and fork brace coupled with those bitchen monoblock calipers, HH pads with a modern tire is really, really a nice set up.

Then again....the USD forks gets the chicks...

[red]

Is there a reason I should want to keep the anti-dive?

86FJNJ,

The anti-dive system was a good idea that did not work out very well.  Most riders ditch them.

You can eliminate the anti-dive units, but you need to connect the holes to pass fork fluid.  The cheapest way is to leave the anti-dive units in place and run the brake lines straight to the calipers. The exposed hole (where the brake line went) can be filled smoothly with any sealant.

For a cleaner appearance, you can remove each anti-dive unit, and separate the top half from the bottom half.  Re-install the bolt-on part to the fork tube, upside down.  Fill any exposed holes smoothly with some sealant. Done deal. The suspension will still work normally, as it should.