Front and rear shock psi

[Bubba717]

Just wanted to see what the average air pressure you would usually keep the front and rear shocks at .

[SgtSlag]

I replaced mine with Progressive products -- no air assist required. I believe the front forks are 7 PSI (hand-powered air pump only!!!), and the rear shocks are 35 PSI, by the book?

Progressive Fork Springs are dual-rate coils, and air is not recommended for them.

Progressive makes sealed shock replacements, which are easy to install. They alleviate the issue of air requirements. Cheers!

[Deep Thoughts]

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[Nails]

I ride solo, lightly loaded and still prefer the rears at 36 psi at level 3 damping. Cornering is not as much fun with a softly sprung suspension.
When I was on the sagged out front fork springs, I ran max recommended on the fronts...9-10 psi. That pressure is doing for the forks what the springs are failing to do; providing damping force. With the Progressives, I still keep 1-1.5 psi in them ( I have a high resolution air guage) for the added damping over rough roads. I am using ATF as fork oil.

Low-speed handling is different from cornering, but I've come on folks who confuse the two. High pressures (tires and suspension) generally give better parking-lot performance, but might not actually yield better cornering performance. Not saying you're doing that, just saying that I've seen that before.

For my part, I emphasize transitions in quick corners -- "dancing", akin to what the skiers call edge-to-edge performance. I've found good confidence with low pressures and light oils, relative to what others report here. I'm also solo, maybe in the low half of bike-load weights even touring with camping crap, using Progressives and stock shocks. I have made an effort to centralize weights. I often ride "B" roads ... or worse.

[GrandpaDenny]

I ride solo, lightly loaded and still prefer the rears at 36 psi at level 3 damping. Cornering is not as much fun with a softly sprung suspension.
When I was on the sagged out front fork springs, I ran max recommended on the fronts...9-10 psi. That pressure is doing for the forks what the springs are failing to do; providing damping force. With the Progressives, I still keep 1-1.5 psi in them ( I have a high resolution air guage) for the added damping over rough roads. I am using ATF as fork oil.

Adding air pressure to the forks increases preload, not damping. Damping is the resistance to the tendency of a spring to oscillate - to keep bouncing. This is determined by the oil viscosity. If you feel your forks are underdamped, you need a heavier oil.

I have heard that a couple of pounds of air can be useful in Progressive forks. As for me, I find I need to keep bleeding the air out, as the forks get way too stiff and the ride height (and hence headlight aim) increases.

I'm in the (prolonged) process of figuring out just what the "ideal" fork oil level is for me (close to 300# in gear and until recently rarely rode two-up). My theory is that (actually, I guess it's a hypothesis - man it's been many decades since I've formally used the scientific method LOL) what is actually needed is a lower oil level in the forks, not a lighter fork oil.

I have a new kinda-sorta-girlfriend who likes to ride with me, and with my present setup I haven't noticed a whole lot of difference in the ride with her aboard. We've only taken a couple of short rides between our homes so far, as I'm awaiting my new tires to arrive (Shinko 777HDs front and rear, and believe it or not, whitewall in the front - she has a hose at her house and said I can wash Gertrude there so I might actually start keeping the bike clean). With my previous setup of 10wt. oil at 145mm and rear Progressive shocks preload set at 4, the ride was MUCH improved with a second person aboard. I'm now running 15wt. oil in the forks and have been slowly forcing out tiny amounts of oil through the air valve (started at 145mm) which has GREATLY improved the ride, and the rear shocks' preload set at 3. At some point I'll decide I've got it "just right" and will measure the fork oil level and let you guys know what I've come up with.

[GrandpaDenny]

I just discovered something looking through the Supplemental service manuals - the recommended fork oil level is 157mm, not 140. No wonder so many of our bikes ride like crap with standard fork oil. See page 12-2 in the Supplemental manual. The earlier (87-90 I guess) spec 177mm. Remember, the original Service Manual was written for the 1986 Voyager XII which is substantially different from the '87s and up.

There is a second supplement for 1999-2003 models as well.