1986 250R Forks: Max preload spacer size?

[Dammit!]

Anybody know how big of a preload spacer you can use in '86 R forks before you start interfering with the amount of travel?

I've got two inch PVC spacers in there now. I have a set of NASA adjustable caps that will give me up to about another inch of preload (maybe slightly more). Just trying to figure out how far I can go.

It works pretty good the way it is but I can still bottom the front end out when the hitting the base of a dune pretty easily. I plan on switching to progressive springs eventually but I heard you need even bigger preload spacers with those. Hence my question.

[DeePa]

damnit, as far as progressives are concerned, i didnt need any spacers when i installed them in my 85 r forks. When i installed them in my 86 z forks, the instructions told me to make 1.3 inch spacers to make them the same length as stock springs.

I dont think thats what you were concerned with, but i figured id try to help.

[Dammit!]

My question isn't just because I plan to get progressives (who knows when that will happen the way things are going, lol) but really just so I know how long of a spacer I can put in there with the stock springs. My forks feel good but they still bottom just a little too easy. I would think another inch of preload would be ok but I don't know for sure. I'd like to know exactly how much is too much.

Something else I thought about doing was taking the spacers out and putting a stiff short spring in there. Like a make shift dual rate setup. I still need to know how much room I have to work with in there though.

[vegas250rr]

can you use a clear piece of tubing... like lexan and a make shift press to measure the collapsed height of your springs? that might get you to your number faster than trial and error

[vegas250rr]

alright I came up with another Idea... it involves PVC pipe and a floor jack.
here you go.

sorry for the crude drawing. but it was done really fast

[brapp]

best way is to measure the fre elength between the coils in the springs. i was told this bu a suspension guy years ago when i was tryign to stig gin up my 85 cr250 forks

[vegas250rr]

best way is to measure the fre elength between the coils in the springs. i was told this bu a suspension guy years ago when i was tryign to stig gin up my 85 cr250 forks

.... WHAT ????

[Dammit!]

That drawing looks like it would work Jeremy. With the luck I've been having lately though, I don't know if I want to try it. I can just see the trip to the dentist after the spring gets loose and knocks some teeth out. :lol:

I was thinking maybe I could measure the size of the metal/wire (can't think of the proper term right this second) itself and multiply it by the number of individual coils to get the collapsed length. Think that would be accurate?

I'm assuming that I can add a spacer equal to whatever the length of the collapsed spring is under 9.8 inches. Like if the spring is 7 inches, I could add a 2.8 inch spacer and not hinder the maximum amount of travel. However, I really don't have a firm grasp of how everything works in there to be honest. All I know at this point is the free length should be 22.42 inches and it sure as hell doesn't look like it could compress to under 8. :wondering

Edit: I don't have a micrometer by the way. If anybody happens to have one and also happens to have a 250R fork spring handy, let me know what gauge that spring is please. :D

[vegas250rr]

haha, you could always wear a welders mask while you try it....http://i34.photobucket.com/albums/d116/goodgirl20/smiley-welder.gif

as for measuring the gaps.... I dont know that I would trust it to be totally accurate, it might get you close enough for what your trying to do. but I believe the only way to do it is to compress it with a jig or press

[Dammit!]

Not the gaps but the gauge of the wire itself. I'd think the gaps in between wouldn't be consistent enough to get an accurate measurement.

[MyMistress86R]

Just curious here, but what weight oil are you running in the forks now Dammit?

[brapp]

i was told by all car at reactive suspension that the spring can not compress more than it has space between the coils available. and if you have a total of 6 inches between coils you woudl have 3 inched of pleload to play with just what i was told by someone who works on mx suspensions everyday and my .02 cents

[Dammit!]

Just curious here, but what weight oil are you running in the forks now Dammit?

I honestly don't remember. Probably got an empty bottle in the garage somewhere. I like the way they feel though. I thought about experimenting with different weight oils but I think a thicker oil would effect my rebounding which I'd rather not do.

It's times like these that make it frustrating as hell to live so far away from a good riding spot. Back when I could just ride out of my garage it was so easy to just experiment with a hundred different combinations of things. Now if I make a change I'm pretty much stuck with it for a whole weekend of riding.

At some point I'll probably just break down and rebuild the forks with the new progressive springs and a gold valve kit and the whole nine.

[MyMistress86R]

Since you seem to be happy with your oil weight and aren't ready to seriously consider the progressive spring upgrade, there's not really much advice I'm willing to put out there for you.

Here's what I know, take it as you will...

I have an 86R with progressive springs and 7wt oil. I'm looking to go up to 10wt just to tame a little bit of bounce I have. With the progressives, I run them without any spacers and have yet to truly bottom them out. When I first installed them, I did experiment with 1" spacers and it was all I could handle just getting the caps back on right. I would imagine with 2" spacers it would damn near take two people to do it. If you are running original 86 springs, they are likely as tired as my Grandma, regardless of what they "look" like.

Based on what I get from what you are saying, I believe progressives, 1~2" spacers and 10wt oil would be very close. One other thing to consider about the oil weight vs. rebound rate is that if you put 2~3" spacers on your stock springs and then tweak that even more with your NASA caps, your spring tension alone would likely overcome even 20wt oil in most situations.

Ok...my $.02 has been spent...lol.

[Dammit!]

Well see, in the short term I just want to be certain that a 3 inch spacer is not too much (and purely out of curiousity I'd like to know what the absolute MAX you can get away with would be). I haven't put my NASA's on yet because I'm not sure there's room. Just using those tightened down all the way would probably be enough to fix the bottoming out issue until I can go all out and get the progressives and gold valve kit.

Getting the fork caps on with the two inch spacers I have now was a complete PITA so I'm right there with you on that one.