help me choose what to do with my forks please

here goes

im rebuilding my seca, and after months of thinking, i still havent decided what to do with my forks. theyre '82 750 seca forks, with the anti-dive and air assist.

the goal is to make them work good. seemingly the seals dont leak. i didnt feel anything wrong with them when riding (havent had a bike with anti-dives before), but after removing the anti-dive piston housing i noticed that the other plunger donesnt quite plunge.

im doing the bar mounted m/c upgrade along with ss lines. at my nearby shop they make lines but the length of the line is not a factor for the price. so short lines from the caliper to the anti-dive cost almost as much as lines from the m/c to the caliper. a fact that makes me want to loose the anti-dives. of course i could use a combination of the two and put the original short rubber lines from caliper to anti-dive..

so, what do you think would be the best approach?

the option i would like to choose is to loose anti-dives and install progressive springs with heavier oil. also loose the air assist feature (so i have more options with my clipons). and cut off the fender mounts too, i dont need them.
has anyone done this? whats the experience?

has anyone removed the air assist feature?

the other option is to do the standard stuff, rebuild anti-dives and change fork oil and go with the stock springs (or progressive) and air assist.


try to make up my mind please

 

here's what i did with the anti-dive, with a 1.25 inch spacer on top of the original springs and the air valves installed but no air
i don't remember what kind of oil for sure but it might be 10w30 motor oil
they work fine for me

 

Both the Anti-Dives on the Seca750 and the Seca900 are young Hollywood Starlets.
"Heavy Maintenance".
If you Clean them ... Annually; they won't act-up and quit.
Maybe.

The Cycle Press said the Yamaha Seca's Anti-Dive Forks weren't anything to write home about.
Marginally effective; at best.

The 900's have an external adjustment at the bottom.
A little-bitty "I-can't-believe-it's-not-butter" soft, brass selection screw that seizes when exposed to light unless bathed in Anti-Seize Compound.

The key element to both Anti-Dive Elements is keeping a PLUNGER from not getting stuck in the the Port it needs to have travel.

Helping the Dives with Progressive Springs and the recommended Pre-Load will get them to perform Anti-Dive functioning.

They work better with heavier Fork Oils.

(I'm happy with 'em. I'm running straight Hydraulic Jack Oil.)

 

thats nicely done polock, i read about it before and thought if youd block the holes on the fork beneath the plunger part like you tried, but grind a pathway for the oil to move, do you think it could work?

thanks rick, extensive as always. i want to make my forks more care free also. ditching the anti-dives seems to be the way. if i ever change my mind ill just hook them back up.

about the air assists, what would you use to block the little air passage hole, if it would be underneath the top triple clamp or clipon clamp? some thin rubber or what...?

 

Change out the fork caps for a plain set.

 

You crack me up Rick... you should be a columnist somewhere, beside the xj forum I mean :wink:

 

yeah that put a smile on my face too



bigfitz i have the 17mm hex nut fork caps, and the air valves are beneath the top triple..

or what did you mean?

 

if you block the two holes, it almost locks the fork but if you grind a pathway between the holes 1) your going to have to make a gasket because the o-rings won't work anymore 2) the pathway will be the control for the compression damping
the small air hole, the best way would be solder or weld it but if you clean it real good on both sides MAYBE RTV or some kind of sealer would work, since it's under a clamp
i doubt rubber or tape will fit in the clamp with the fork but you want the forks clamped solid, metal to metal, anyway

 

whats rtv? its a paint shop around here ha ha

so the size of the pathway would be a factor or what? way easier your way if thats so

 

RTV= room temperature vulcanizing = silicone rubber (sealer) in a squeeze tube
this stuff
when i tried with the holes blocked, the forks were VERY stiff like almost locked so the size of the path between them must control oil flow
that's where the valve is that was designed to control the oil originally
there is a picture here somewhere that shows the inside of the anti-dive unit if you want to take yours apart and clean it up, not a hard thing to do

 

thanks polock, thats something i had in mind too. my nearby shop has permatex products

and yes i have seen the picture, its very informative.

still havent decided actually. came to my mind i could use the oem hoses from the anti-dives to caliper and ss from there up.

it may be best to make the dives work first and then decice if i need them or not..

same goes with the air assists, not going to rtv the holes shut before i have experimented with different air pressures too.. or with no pressure or a little pressure, ive read that its 5 psi max?

need to get to work with this