Front shocks have no travel

[Anonymous]

Hi fellows. I'm new to this board. I recently bought an 82 GS750E and have come to find that the ride is really rough. I test rode the bike in the seller's neighborhood on very smooth pavement. This bike will loosen your fillings going over railroad tracks and such. It has the anti-dive mechanism. The lack of suspension seems to be in the front end. Where do I begin? Could lack of proper fork oil or fork oil level cause this?

Is this something that the anti-dive has effected? Any help would be greatly appreciated.

[daveo]

does it have air preload? Could be too much. try 7-10 psi, could be overfilled with fork oil also, not sure of correct volume for your model, the anti-dive should only activate when front brakes are used

[Anonymous]

Have to agree with Dave, your best bet is to change your fork oil and make sure of your air pressure. Don't know about the '82, but the recommended pressure for '83 and up is 3psi. The anti-dive doesn't do anything unless the brakes are applied ( and not always then ).

[Anonymous]

I have no air adjustment on my shocks. It seems that the forks are collapsed to as short as they can go. Maybe my springs are shot or missing?

[Anonymous]

Boys, I've been out of cycling for 18 years while raising kids. I am out of touch with "modern" motorcycles like my '82 GS 750e. I DO HAVE air preload according to the lable on the left shock.

I measured the distance from the bottom of the lower triple tree to the top of the dust cover and it is 7 3/4 inches with thw bike on the side stand. I get the same measurement with the bike on the center stand and the front wheel off the ground. Shouldn't a 750 at rest on the side stand collapse the front suspension at least a little?

Did the previous owner have the air preload too high? Where do I check it? How do I fill or lower it?

I borrowed a Clymer manual from the local library and it makes no mention of the air preload anywhere.

Help!

[daveo]

Damn modern bikes!!! You need to loosen the 10 mm air retaining cap,'D' on the front of each of the collars attached to each fork leg right above the lower triple clamp, these maintain air pressure in each leg independent of each other, on the left hand collar is another chrome cap '23' under which is a schraeder valve 'F', like on a tire, with the 2 other caps open you can then check overall pressure at the valve, you need to use a low pressure guage. The best way to add air is with a hand pump so you don't over fill!!!

[Anonymous]

Dave,

I did measure the air pressure now that I know where the valves are. It was off the charts! Literally.

My dial type air gauge goes up to 60 psi. The needle spun past that and stopped at zero. There may have been 80 psi or more in each tube!

I lowered the pressure to 10 psi and took it up the street for a test ride and she rides more like I expected a "modern" multi-cylinder bike to ride.

Question, does it take a special tool to adjust the spring preload on the stock rear shocks. They are at their softest setting. I'd like a little firmer back end.

By the way. Thanks for the help.
Dave

[earlfor]

Yep, there is a special tool for adjusting the rear shocks, but I misplaced mine some years ago. :-) A couple wraps of duct dape around each jaw on a pair of channel lock pliers works just fine. Just grip the lower ring on the shocks (one with the notches) and rotate it where you want.

earl

Dave,
Question, does it take a special tool to adjust the spring preload on the stock rear shocks. They are at their softest setting. I'd like a little firmer back end.

By the way. Thanks for the help.
Dave

[daveo]

Dave,

My bike had no balancing line but...I did measure the air pressure now that I know where the valves are. It was off the charts! Literally.

My dial type air gauge goes up to 60 psi. The needle spun past that and stopped at zero. There may have been 80 psi or more in each tube!

I lowered the pressure to 10 psi and took it up the street for a test ride and she rides more like I expected a "modern" multi-cylinder bike to ride.

Question, does it take a special tool to adjust the spring preload on the stock rear shocks. They are at their softest setting. I'd like a little firmer back end.

By the way. Thanks for the help.
Dave

Glad it was something easy for you!!

[KGB]

Now keep an eye, actually both eyes for both tubes.
If they had over 80lbs psi in them the seals could have been "moved".
With the bike stopped, squeeze the front brake and bounce the front up/down a few times. Any oil on the fork legs?

If the previous owner put that much air in the fork, I run about 6lbs psi in mine, did he try changing the oil in them also?

[Anonymous]

Fine tuning the air preload on the front forks

I've just realized that when I set the air adjustable preload on this 82 750e, I did it with the bike on the center stand. I set it to 10#s of pressure, which felt okay but still a little stiff. I went back today to check the pressure with the bike on the side stand and, of course, the pressure read 20#s. What is the correct procedure for setting the air pressure in the forks? ...on the side stand, the center stand or front wheel off the ground?

[daveo]

Re: Fine tuning the air preload on the front forks

I've just realized that when I set the air adjustable preload on this 82 750e, I did it with the bike on the center stand. I set it to 10#s of pressure, which felt okay but still a little stiff. I went back today to check the pressure with the bike on the side stand and, of course, the pressure read 20#s. What is the correct procedure for setting the air pressure in the forks? ...on the side stand, the center stand or front wheel off the ground?

I would check it on the sidestand, how do you balance between the fork legs, as you mentioned you had no balancing tube?

[earlfor]

I have a 79 and an 81 750E. The distance (bike on sidestand) between the underside of the lower triple tree and the dustcover on both of them is 6 3/4". With the forks fully compressed, the distance between the underside of the triple tree and the dust seal is 3". On the top of each of your fork tubes you will see a small hex cap nut. Unscrew the nut and underneath is the air fill valve. Its a schrader valve just like in a tire. Bleed the air out of both fork tubes. (both my 750 and 1150 have air valves and take aprox 3-4 psi max, BUT....I prefer to use zero air pressure in my forks for a better ride) It appears your forks are fully extended and not compressing. My best guess is that the fork oil has either turned to sludge and cannot compress or the fork oil weight now in the fork tubes is way too heavy. Remove the fork caps on each fork, (after releasing an air pressure), then unscrew the drain plugs on the bottom outside of each fork and drain the old oil. If sludge comes out and it will not drain decently, you can pour some kerosene into the forks to dilute the goo and get them drained. Refill each fork with either 10, 15 or 20 weight oil. (the lighter the weight, the softer the forks will be) Your bike takes 8 ounces (U.S.) in each fork.

Earl

Boys, I've been out of cycling for 18 years while raising kids. I am out of touch with "modern" motorcycles like my '82 GS 750e. I DO HAVE air preload according to the lable on the left shock.

I measured the distance from the bottom of the lower triple tree to the top of the dust cover and it is 7 3/4 inches with thw bike on the side stand. I get the same measurement with the bike on the center stand and the front wheel off the ground. Shouldn't a 750 at rest on the side stand collapse the front suspension at least a little?

Did the previous owner have the air preload too high? Where do I check it? How do I fill or lower it?

I borrowed a Clymer manual from the local library and it makes no mention of the air preload anywhere.

Help!