Air Shock Balancer Mod


- kennethrosado

I like my air shocks on my Vulcan Drifter, but keeping them balanced and charging them up when going from 1 to 2-up was a bit of a drag.  Unfortunately, the old Progressive Suspensions AFB1 Air Shock Balance Kit is no longer available and I bunged up one of the fittings so it no longer held pressure, so I started looking around for alternatives.  

I looked on Progressives site at the Harley air shocks. In the instructions I read that Progressive made adapter kits for Adaptor for Honda GL1100/1200 Aspencade, Adapter Part #30-5082 and Adapter Part # 30-5086 is required for Suzuki Cavalcade or Kawasaki 1300 Voyager.

Progressive shock springs pdf

Let me interject here that Metric motorcycle manufacturers do NOT use common Metric thread sizes, they use 8 – 1.0 and 10 – 1.25 and believe me when I tell you, NO ONE makes them in the regular world. So these kits are really my only option.

Right. So these kits should be interchangeable; meaning Honda, Kawasaki, Suzuki and I assume Yamaha use the same size threads and openings; at least that was my thinking.  

I Googled the kit numbers and found them at Power Sport Parts for $12 (TR77-0915) and $17 (TR77-0919

This is what the kits come with:

30-5086 – a male/female adapter; 1 T-fitting; 1 tube connector/crimp; 1 tub nut; 2 rubber O-rings.

30-5082 – 2 male/male shock adapter fittings; 2 tube connector/crimps; 2 tub nuts; 6 rubber O-rings.

One more thing before you get started, you need hose.  You can go polyurethane or nylon; polyurethane is very flexible but I chose nylon because of what I read about it…instead of paraphrasing it, I’ll just quote it.  You decide on your own.

"Nylon is a good choice for general-purpose pneumatic applications. Although nylon is not as flexible as polyurethane it is much stronger and has a higher pressure rating. Due to its strength, nylon tubing can be manufactured with thinner walls while still maintaining high pressure ratings. This walled tubing allows for a higher flow rating for a given outside diameter. 

In addition to its strength, Nylon is heat and light stabilized. Nylon’s combination of high pressure rating, high flow rate, flexibility, and toughness make it the ideal choice for most compressed air systems.”  Also, I should add that it is flexible, but not to the degree of polyurethane

I got mine here - http://www.poweraire.com/nylon-tubing-black-tubing-c-27_207_271.html - I chose black because it matches the frame, but they come in 7 colors, 8 in polyurethane.

Cut 2 pieces of the tubing/hose about 15 – 17 inches, set them aside. Don’t worry there’s plenty for mistakes and/or customization.

On to the project; I started with 30-5082 and the shocks.  

The instructions tell you to do a lot of things you don’t need to do, like remove the shocks. You don’t need to do that.  Just remove the valves from the shocks carefully, they’re brass and soft.  

Once you’ve done that, carefully remove the O-rings from the original valve fittings and install them on the SMALL end of the silver fittings you see in the picture above.  If they’re bad, any cycle dealer should have a set.  

I tried using the spares in the kit and had difficulty getting the mover the threads, one ended up flying off somewhere, never too be seen again.

Once you install the O-rings on the new fittings, lube the threads and the O-rings with a bit of oil and HAND screw them into the shocks, when you can’t HAND tighten them anymore, tighten them down to 90 inch pounds with your socket set.  Take your time here because any mistakes will be spendy.

See below for comparison. The old brass valve fitting and the newly installed silver fitting provided in the kit. The O-ring you see on the old brass one is the one you transfer over to the silver one. The valve fitting that you see is a spare I had from a wrecked shock.

Now you can install the hoses, those small O-rings, hose nuts & connectors to the fittings. The instructions say 1/8th “of the hose should stick out past the O-rings.

It should look something like this.

Next put some lubricant – soapy water or if some very light “rubber friendly” oil like Dexron 3 – on the O-rings and the Gemini shaped “tube connector” (it works like a crimp) and work it gently into the fitting you just installed on the shocks.

Push the hose & crimp gently in taking care not to push so hard that too much hose goes into the fitting. If that happens, just pull everything out and reset the O-rings on the hose, add more lube and try again.

When the “tube connector” or crimp seats against the fitting like this below.

Hand tighten the “tube nut” until it seats and give it no more than a ¼ turn. FYI, they’re plastic.  I’ve put on over 3000 miles since I did this and have not lost any pressure.

This is the way I ran the hose from the shocks into the battery area under the seat.
Left side (tool kit side that opens with a key) ; this way it keeps from getting banged up every time you open and close the side cover  

Right side (Fuse side with the Phillips head screw) I put the cover back on to show how the hose should curve.

Now it’s time to open 30-5086.

This is pretty easy; with the T-fitting in hand, figure out where you want to attach it under the seat.

When you've decided what you want, take the 2 hoses from the shocks and the T-fitting; unscrew the opposing nuts, slide each one over the hoses and cut the hoses roughly to the appropriate length and slip the hoses into the T-fittings.  Don't worry about the lack of crimps, they're built into the T-fitting.  

Tighten the nuts by hand until nice and snug.  Again, this is plastic so be careful and a lot of pressure isn't necessary.

After you've tightened the opposing nuts, you need to stop and figure your next location.  As you can see in these pictures, the male/female adapter on my bike has a very short tube.  In my case I was going to run a long piece of tube from the T-fitting back down into my tool box tray behind the left side cover and fit the brass valve from one of the shocks into it. This way I could just open the cover and adjust the shocks anywhere any time.

Instead, I found a hose from a Honda air-shock system (on eBay - $11 delivered) that I thought I would attach to the frame and provide easy, external access. So I use it instead, screwed it into the 
Male/Female adapter, then I zip-tied it down so it wouldn't short out on the battery. 

Unfortunately, I couldn't find a spot on my Drifter that wouldn't interfere with my bouncing fender, and I convert my seats from single to 2-up regularly, so I needed clearance on the seat support bar on the back side of the frame and battery.  

For those with fixed-fender Vulcan's, there are places you can run the hose to.  Here is the end fitting to give you an idea of what you'd be working with. The double nut set up should work nicely. The brass fitting is off the shock.

So, I ended up tucking it into the left-side tool box, not as nice as I planned, but easy enough to get to and after 2 seasons of riding (just under 3000 miles) single and 2-up, it is still holding pressure and working great.

I think that covered it all.  If you have any question, please ask.