front air forks

[rckrzy1]

Who carries progressive springs for our bikes ? I found one site but it only
listed the 750E/S and I know my T is a bit different as I only have one brake rotor.

[bwringer]

How low should the forks be under weight? When I sit on my 78 GS1000 it looks like I have about 2 inches of travel to bottom it out. (I'm 215 + clothing.) Is that normal? I haven't checked the pressure or oil level. How much oil for my bike?

Ideal sag with the rider and gear on the bike should be about 1/4 of total travel. Most GS forks have a little over 4 inches of total travel, so sag when you sit down should be about 1 inch. (Put a Zip tie loosely around one fork tube to help gauge sag.)

I have Progressive fork springs, and after experimentation, I've ended up with spacers about 1.5 inches longer than initially recommended in the instructions. It takes an Act of Congress to get the fork caps on, but it's well worth the trouble. Much more comfortable and controlled for me, but they would be far too stiff for a lighter rider -- my bike doesn't compress its forks at all under its own weight. With me in the saddle, sag is about 1-1/8 inch. Close enough...

My complete $0.02 on setting fork oil levels and mixing your own custom blend fork oil is in this thread:

http://www.thegsresources.com/_forum/showthread.php?t=91084

[mixongw]

I use my shop compressor with an adjustable regulator and gauge. I set the pressure to whatever I want and apply the air. Works great.

[duaneage]

It is interesting that my forks had a label that stated up to 36PSI could be run in the forks. Who's right, Clymer or Suzuki?

[pntrdave]

I put new progressive springs in my 78 gs 1000, I must not have put in enough spacers because front was way to spongy (soft) I ended up putting a regulator on my air chuck and adding first 10 lbs of air still a little soft, then 20 lbs of air way to hard ended up with 15lbs of air and it's just right. Should I add spacers and forget the air or ride it the way it is????? opinions please

[Sandy]

I put new progressive springs in my 78 gs 1000, I must not have put in enough spacers because front was way to spongy (soft) I ended up putting a regulator on my air chuck and adding first 10 lbs of air still a little soft, then 20 lbs of air way to hard ended up with 15lbs of air and it's just right. Should I add spacers and forget the air or ride it the way it is????? opinions please

Just curious as to whether or not you ended up with the correct springs. The ones I installed on my '79 GS1000 required, and came with, no spacers. The springs stick out of the fork tube about 1/2 inch, combine that with the 3/4 inch or so that the caps compress the spring and I have about 1 1/4 inch of preload with no spacers. The bike is naked with super sport bars and I weigh about 210 and am using 15W Belray fork oil and no air. I was considering changing to 20W but after just coming back from a fairly aggressive ride on some not so smooth backroads I'm going to leave everything as is for now. The roads didn't have broken pavement but did have the usual frost heaves, uneven pavement and a bunch of damn corners. I was having a lot of fun at 70 to 100+ mph and the bike felt very good and only had the usual wiggles and wobbles that seem normal on these old bikes when you start pushing them hard. So I guess I'm a little perplexed as to why you're having issues getting yours setup as mine was not even getting close bottoming during the ride. Looking at the tie wraps I use for setting up front suspension I still had about 1 1/2 inches of travel left after this ride. Oh yeah, the springs I have are the Progressive brand springs, sometimes there is confusion between progressively wound springs and Progressive brand springs. I've assumed you're talking about Progressive brand springs.

[pntrdave]

I ordered my Progressive brand spings from Dennis Kirk, when installed in the tube they were just flush with the top of the tube added 1 washer and the end cap for the spring then the tube end. Used 10w 20 oil in the forks. Front end was real soft, but I rode it with no air, I feel that is what caused the tank slapper to occur http://www.thegsresources.com/_forum...t=tank+slapper
Since I put the air back in the forks I've had it up over 100 several times and it is solid as a 28 yr old bike gets. I'm 6 ft tall and 290lbs. It rides a little stiff but it works great for me.

[Sandy]

I ordered my Progressive brand spings from Dennis Kirk, when installed in the tube they were just flush with the top of the tube added 1 washer and the end cap for the spring then the tube end. Used 10w 20 oil in the forks. Front end was real soft, but I rode it with no air, I feel that is what caused the tank slapper to occur http://www.thegsresources.com/_forum...t=tank+slapper
Since I put the air back in the forks I've had it up over 100 several times and it is solid as a 28 yr old bike gets. I'm 6 ft tall and 290lbs. It rides a little stiff but it works great for me.

With your weight that set up sounds about right. I prefer to run with no air because it's always been a bit of a fiddle for me. In your case I'd probably just run the air also, I don't think I'd want to fight with putting a longer spacer in the tube. Glad you've found a combination that works.

[Clone]

I run about between 14-17lbs. 14 by myself and up to 17 with my wifey on the back. I like the front end pretty stiff, it sags about 20mm or so coming off the centerstand, so I figure this is good. My forks don't bottom out during panic stops so I always figure this is a good pressure.8)
putting air in is usually done at the service station (I use the pumps that you can dial a pressure on) then I screw an extension onto the fork valve. This works pretty good for me.

[83GS1100E_Tornado]

There is a schrader valve located on the fork or around the triple tree.
My 1000S has individual air caps on top of the forks, so each one is done seperately. The 1100E had a single valve for both forks located on the right side, sitting on the bike, near the reflector mounted on the fork.

Why can't I find my valve to add air (83 GS1100E)? All I can see is one line that appear to go from one side to the other, and no way to add air? I'm confused? Here's a pic!

[Clone]

under the cap number 9 on the left lower triple is your air valve.

[83GS1100E_Tornado]

Air shocks

I found it, thanks for the help!!!

[Brianjonesphoto]

Here's the skinny on the air preload. I've been riding mountian bikes forever and this system is now used by a few manufactures. It's a great system that allows you to fine tune a coil shock.

According to my factory manual for my 550 the standard runing pressure is 4.2psi and the max pressue is 35.5psi That's quite a range of ajustablity. You can pick up a bicycle shock pump pretty cheap these days. one like this
http://pricepoint.com/detail/11580-2...-Fork-Pump.htm
has a bleed button to get just the right pressue in there. There's alway a little pressue loss do the the air volume of the hose when you disconnect, but I can assure you that your not loosing any pressue from the fork. This pump comes with a 200 psi gauge. There are low pressue pumps out there, but they are pretty tough to find. If you really want super accurate readings you could easly replace the gauge on this pump.

As far as other posters saying that the air will mix in with the oil. It won't there's already air (or some other gass) in the fork leg no matter what. Putting it under pressure will actually reduce foaming slightly since the pressue makes it harder for foam to form.

Hope this helps.