Fork air question

[C.V.]

Is there a tricky way to eliminate the fork air neccesity in my '79 850...without the progressive springs upgrade? My budget is shot at the moment, and progressives will have to wait.

I have a slow leak in the left tube due to a mangled valve, and I am looking for a stopgap solution untill i can afford the progressives. I also know new valves are available, but i am having trouble flying all this stuff in under the wifes radar... so I'd rather just lose the air.

I know that springs can be cut down, or the preload can be increased, will any of these help to eliminate the air?

I am not heavy, 260 to 265, depending on what I ate...

Just looking for some suggestions. thanks guys.

[Billy Ricks]

Is there a tricky way to eliminate the fork air neccesity in my '79 850...without the progressive springs upgrade? My budget is shot at the moment, and progressives will have to wait.

I have a slow leak in the left tube due to a mangled valve, and I am looking for a stopgap solution untill i can afford the progressives. I also know new valves are available, but i am having trouble flying all this stuff in under the wifes radar... so I'd rather just lose the air.

I know that springs can be cut down, or the preload can be increased, will any of these help to eliminate the air?

I am not heavy, 260 to 265, depending on what I ate...

Just looking for some suggestions. thanks guys.

PVC spacers can be used to adjust the preload. Just use a fender washer between the PVC and the spring. You'll need to try different lengths to get the sag right. Sag is the difference in fork length with the wheel off the ground with the fork fully extended. Take a measurement for that then set the bike on the ground and put your weight in the seat. Take another measurement and see what the difference is. You should shoot for about 1 1/4" of difference.

[focus frenzy]

yep what Billy said, I would just add use schedule 40 pvc spacers. I used PVC couplers in mine, thicker wall so they are stronger.

[Nessism]

Simply adding more preload will not accomplish much, but cutting out some coils (4” worth or so) and replacing them will a PVC spacer will increase the spring rate. Will this be enough for a 260# guy? Not sure, but nothing to loose so why not try?

[Don-lo]

The stock seals rely on the air pressure to seal correctly, so your seals will probably start leaking. The best stopgap solution is for someone to send you a valve. I may have one in the shed, I'll check.

[C.V.]

Thats interesting, does everyone who does the progressive upgrade upgrade fork seals also?

A new valve would definitely be the easiest fix. How weenie is it that my budget is so blown I'm having trouble with a dam 12 dollar part!?! Not affording it, just convincing the wife I need to spend MORE money on the bike.

[twr1776]

Today 12:09 PM C.V. Thats interesting, does everyone who does the progressive upgrade upgrade fork seals also?

I think most who take the forks completely apart go ahead and do the seals. I did that on mine figuring if I did not the law of averages would get me as soon as I re-assembled them and my seals would then start to leak. If you just swap the springs out then you probably can get by with the seals that are in it if they are not leaking.

[Nessism]

The stock seals rely on the air pressure to seal correctly, so your seals will probably start leaking.

I’m not using air in my forks and the seals are holding just fine. Where did you get this information that the seals are different for air forks?

[Billy Ricks]

Thats interesting, does everyone who does the progressive upgrade upgrade fork seals also?

A new valve would definitely be the easiest fix. How weenie is it that my budget is so blown I'm having trouble with a dam 12 dollar part!?! Not affording it, just convincing the wife I need to spend MORE money on the bike.

Hey, at least you have your priorities straight.

As Ed stated setting the preload for your weight won't do anything for the spring rate. If the bike doesn't dive excessively under braking or compress too much over large bumps then the spring rate might be okay. If you do experience excessive fork travel I'd go ahead and cut the springs then make up for that with additional length on the preload spacers. Increasing air pressure is a poor way to stiffen the ride anyway. As long as you don't have leaking seals don't worry about them.

[salty_monk]

I don't get that about the seals... there is nothing special about them & if there was I doubt they would require air pressure to seal the oil..

There should be no air pressure against them if my thinking of how they work is correct.

Stock springs were way too soft for me on the 1000 even at 165lb, with a 550 I brought back to life recently I was able to remove a small spring from inside & put a spacer in it's place (there was 2 springs in there). That was about 4" long.

I would definitely try cutting at least 4" from the spring & putting a spacer in there. I have a set of stock GS1000 springs too if they are any use.

At your weight I might think about cutting 4 - 5" off & putting a spacer back at 5 or 6".

I would also consider upping the oil weight from 15w to 20w as that will 1. help the damper control the extra weight in the spring 2. increase compression damping on the downstroke which will also serve to help "stiffen" the spring (it will help to stop it diving).

Dan

[Billy Ricks]

I was going to bring up heavier oil to increase damping but figured since he was on a budget... That is a good recommendation though for everyone reading this thread.

[C.V.]

Hey, at least you have your priorities straight.

As Ed stated setting the preload for your weight won't do anything for the spring rate. If the bike doesn't dive excessively under braking or compress too much over large bumps then the spring rate might be okay. If you do experience excessive fork travel I'd go ahead and cut the springs then make up for that with additional length on the preload spacers. Increasing air pressure is a poor way to stiffen the ride anyway. As long as you don't have leaking seals don't worry about them.

The dive is pretty bad, but it doesn't bottom out. It improves dramitically with a fresh shot of air, but reverts after a bit of time. My real issue, I think, is uneven dampening due due imbalanced air pressure between the 2 fork legs, ends up feeling generally unstable, particularly while cornering. I can't check the pressure in the left leg, due to the mangled valve.

Is there a trick to cutting the springs, or just bust out the ruler and the hacksaw?

Hey, at least you have your priorities straight.

I know who butters my bread! She's really pretty good, but I just spent a bunch of money on other stuff, and its getting to be a harder and harder sell. The "safety issue" excuse seems to lose credibility after a while...

[Billy Ricks]

Hack saw will work fine or an angle grinder if you have access to one. Just try to cut it in a way that the end of the coil is flat relative to the surface it contacts. Take a file to the end of the coil if you have to. If you're able to change the fork oil that will help too.

[Nerobro]

I am looking through my boxes of paintball stuff, for a Low Pressure Regulator, and some hoses.

All forks leak... as far as I can tell. But a few psi makes a world of difference. :-)

[C.V.]

I was going to bring up heavier oil to increase damping but figured since he was on a budget... That is a good recommendation though for everyone reading this thread.

No, I may do that...if i can sneak out and get it under the radar, I will, just can't be ordering parts much now..."Another package from Z1, what did you buy this time?"

Except I already have a fresh quart of 15w. Hmmm...

Thanks to all of you guys, very helpful info.

I'll see you in a couple weeks Dan! Maybe you too Ed?