Fork Pressure

[Guest]

If the manual says not to exceed 2.4psi of air pressure or something like that, and I want to make my front forks a little stiffer could I add like 7psi. Is this just asking for trouble, I don't have any experiance messing with the forks, so any help or suggestions about servicing them and thing too would be appreciated aswell!
Thanks,
Nick

[Steve]

Probably the FIRST thing you need to do is make sure there is the proper amount of oil in the forks. The best way to ensure that is to drain the old oil and put in fresh oil. If you can't remember when it was done last, it has probably been TOO LONG.

Install the proper amount of oil. Since you want to stiffen it up a bit, use 15-w fork oil. Try it with 2 or 3 psi, see if that works for you.

Chances are, your fork oil is low. This does two things:
1) lack of damping
2) increases the air volume in the tubes

By adding oil, you will actually feel some resistance with fluid going through all the restrictors, damping the movement. With a smaller air volume, the air pressure will increase faster when the forks compress, raising the effective spring rate.

Next step (keeping it cheap, here) is to take the tops of the tubes off to see if you have a spacer on top of the springs. If you have a spacer, make one about an inch longer. If you don't have one, make one about an inch long. PVC plumbing pipe works rather well.

The BEST way to take care of your problem involves laying out a bit of cash. Get some Progressive springs, install them with the proper amount of oil and NO AIR, enjoy the difference. Oh, and you might want to do the rear shocks, too. You won't think it's the same bike. \\/


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[kingofvenus]

More than the recommended amount of air will cause failure of the fork seals. Just add a little pre-load to the springs.

[Nicholaschase29]

So could you please explain to me exactly what to do? I'm kind of dreading taking my forks off, but it does not sound like I will have to. Also, While I am in there I think I would like to change the fork oil, So I drain it out of the bottom of the forks, and then..... Im lost from there... Where? Use a PVC shim to put more preload on the fork, what diameter. Sorry for the ignorance, but I would hate to try to do something myself and then mess something up.
Thanks for all the help on everything.
Nick
P.S king of venus did you do anything with those gsx carbs?

[SqDancerLynn1]

2.4 is probably kg at least on my 850 anywhere 8.5-16 psi in forks. The more air you have in the front The rear also needs a higher setting

[koolaid_kid]

You will not have to remove the forks, just the cap on the top of the fork tubes. There will be a drain screw on the bottom of each fork tube, just remove that and drain the fluid into a can. You will probably want to flush each tube to get the residual gunk; I use ATF for the flush procedure. Just pour a little in and let it drain through. Keep repeating until it comes out clean. Let it fully drain out before proceding.
Then put the drain screw back in and put in the proper amount of fork fluid. (I recommend using 10W.) For a preload spacer, I use PVC pipe, not sure of the diameter, but it will be easy to see once you remove the cap and take the spring out. How much preload you want to add will determine the length of the pvc; I usually start with a 1" piece. Just make sure each side is the same length. And get a washer for each side as well, to go between the pvc and the spring. So you should reinstall in the following order: spring, washer, pvc, washer, cap.
The toughest part of the procedure is getting the cap started back on. Just be persistant and make sure that you don't cross-thread the threads.
BTW, the stuff you drain out will be really stinky, just be prepared.

[mortation]

So what tools are needed for this? The Clymer says use a bicycle pump but what do you need for adapters to connect it? And it says use a pressure gauge but it is round, not like a tire gauge so what would you recommend and how do you connect it? Do you have to take the whole front end apart to change the fork seals or can you just jack it up and slide off the lower tubes?

[chef1366]

Invest in Progressive fork springs and rear shocks. You'll be glad you did.

Removing your forks is not a hard job at all. Just brace the front of the bike so the front tire is off the ground and remove the tire and calipers. Loosen the upper and lower clamps on your triple tree and they should slde right out. To check your fork oil level the fork needs to be removed with the spring removed and the fork straight up and down.

To add dampening you don't neeed to take off the forks just get some 1.75 inch (correct me if I'm wrong) pvc pipe and with a measuring stick measure the distance from the top spring spacer to about 3/4 inch over the top of the forks. (The pvc pipe should stick out of the forks 3/4 inch.) Make your cuts on the pvc even or you will have a hard time rethreading the fork caps.

But I would do as stated above and replace your fork oil and flush out the old.

[koolaid_kid]

So what tools are needed for this?

You would need the appropriate metric box end wrenches and a Phillips screwdriver.

The Clymer says use a bicycle pump but what do you need for adapters to connect it?

Isn't there already a nipple with a valve core in the center, like on a bicycle or car tire?

And it says use a pressure gauge but it is round, not like a tire gauge so what would you recommend and how do you connect it?

Air pressure gauges come in all sorts of formats. They all do the same job. You just need one calibrated per pound of pressure.

Do you have to take the whole front end apart to change the fork seals or can you just jack it up and slide off the lower tubes?

I am starting to get worried now. When was changing the fork seals brought into this discussion?
You might consider bringing someone over to at least look at your bike and offer suggestions. This is a pretty straightforward task, but if you do not feel up to it, you might reconsider. Please note, I am not being negative, but the last thing you want is your bike disabled in your garage. Best of luck.

[mortation]

You might consider bringing someone over to at least look at your bike and offer suggestions. This is a pretty straightforward task, but if you do not feel up to it, you might reconsider. Please note, I am not being negative, but the last thing you want is your bike disabled in your garage. Best of luck.

lol, thanks but the whole bike is already disabled http://www.thegsresources.com/_forum...d.php?t=104537

I am just asking questions as I have not gotten into it yet. I am sure it will be fine to do once I am 100% into it. Right now I am just gathering information as the questions come to me