fork air pressure

[DakRatFink]

Should the pressure be checked with the bike on the centerstand or with the weight of the bike standing up on the wheels?

I get about 5.X PSI in both forks with the centerstand supporting the bike (right around the min pressure according to the Haynes manual) and right around 10.X with the bike standing up balanced on the wheels.

Also, before I adjusted them one was 10 one was 15 ( right around the max pressure) Could the imbalance have been contributing to my high speed wobble (at speeds over 115mph)

 

[DMAN999]

Directly from the Service Manual:​

FRONT FORK ADJUSTMENT

1. Elevate the front wheel by placing a suitable stand under the engine.

NOTE:

When checking and adjusting the air pressure,

there should be no weight on the front end of the motorcycle.​

 

[DakRatFink]

Thanks a lot. I don't know how I missed that in mine. That's why I'm glad I have this forum.

 

[DMAN999]

No Problem, and I'd guess that uneven Air Presussre in the Forks might very well affect the stability of the Bike at Speeds.

 

[DakRatFink]

No Problem, and I'd guess that uneven Air Presussre in the Forks might very well affect the stability of the Bike at Speeds.
__________________

I would guess that, too.
I don't think I have a tire out of balance since they seemed fine last year, but who knows.
As stated in another thread I tightened the steering head bearing and it helped minimally ( with the stem looser the wobble starts from 105-110, tightened to where the fork no longer "bounces" it doesn't onset until around 115-120)

I also wonder if the extra 70 lbs I used to weigh last year help keep the potential wobbles at bay.

 

[naughtyG]

I also wonder if the extra 70 lbs I used to weigh last year help keep the potential wobbles at bay.

Lower the preload on your rear shock absorbers, you may find it makes a BIG difference since you're lighter now.

 

[PDWeyand]

:hmmm: It is funny I hear so much about the wobbles but do not seem to have any but when I am on the bike, the bike thinks it is riding two up with me solo hummmmm :hmmm:

I guess I have enough lead in my blood to keep the front wheel planted and the rear wheel from spinning

 

[DakRatFink]

Will try that. Makes sense. Also I tightened the top nut on my triple down a little more. It hadn't backed off any from my Sharpie mark from the initial adjustment, but I was still able to get another 1/8 turn on. Will see if either or both of these make a difference tomorrow.

 

[sdt354]

I 'm always letting air pressure out.

I turned my Progressive springs around with the tightly wound part up this time. My forks feel a lot stiffer and the braking dive is less. 140mm fluid level. I may have put more fluid in than last time though. So, I'm not really sure the spring position did it? Anyone else? There's a good point to be made for one change at a time.
Steve

 

[Redbone]

I 'm always letting air pressure out.

I turned my Progressive springs around with the tightly wound part up this time. My forks feel a lot stiffer and the braking dive is less. 140mm fluid level. I may have put more fluid in than last time though. So, I'm not really sure the spring position did it? Anyone else? There's a good point to be made for one change at a time.
Steve

I can't remember which way my progressive springs are in but from what I read in the installation instructions it says it matter not one bit. It also states that by putting the tightly wound spring section on the bottom may reduce any spring noise coming from the spring action. I also have Ricor Intiminators, with my fluid level set at stock level for "85-'92 [5.5" from top/ collapsed (I believe)] and 5 wt fork oil, but for the life of me I cannot remember the spacer length. I tried quite a few lengths before I had my sag correct but what I have now is a firm and responsive front end. I added fork springs first and used 15 wt oil, but then added the Intiminators/ 5 wt oil and changed spacer lengths the next year. I should have kept notes on the lengths I used but to set the sag is different in every case so I'm not sure it would be pertinent to another rider. I use no air in my forks but still have the crossover tube and have my froks lowered 2" with the progressive kit.