Progressive suspension

Information and questions on GL1100 Goldwings (1980-1983)
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Motorcycle: 1982 GL1100

Progressive suspension

Postby CapnDenny1 » Tue Jul 06, 2010 3:46 pm

OK, the stock suspension on my '82 GL1100I is either not working porperly or it never did work very well. I am continuing to get it to bottom out at speed on the highway. I don't see any oil anywhere, so I don't think it's leaking.

I've seen some people use the Progressive 416 replacement air shock/spring, and others merely replace the springs with progressive spings and rebuild the stock air shock.

There might be $100 in saving by rebuilding the stock unit and just buying better springs from Progressive Suspension. Now I know this is probably a stupid question, but has anybody tried both solutions to see which is better, or how much better the total replacement 416 is? Is the progressive shock a better shock as well?

I also learned that shock air pressure needs to be set with the center stand down and no weight on the tire. I'm not sure how much difference that makes, but I will check it out. I had 35 psi in the rear(measured when on the tires) and it was bottomin gout a lot.

I don't want the thing to bottom out anymore. A few times yesterday it was downright scary when it happened.


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Re: Progressive suspension

Postby WingAdmin » Tue Jul 06, 2010 6:54 pm

If you pressurize the shocks on the 1100 when the weight is on the rear tire, then you are not getting enough pressure into them. That could definitely be a reason why you're bottoming out.

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Re: Progressive suspension

Postby pbassman » Fri Jul 16, 2010 8:06 am

Had the same problem on my '80 GL1100. A number of other riders said to replace with progressive shocks and I would never regret it. I finally did a couple of years ago and they were right. I got the 412 system and the beauty is they don't need air or oil so they're always at the right pressure. They have four settings on them and I selected the stiffest one at first cause I'm a big guy but I found that too much and dropped it back to the second from last. They sell them at Dennis Kirk for $263 and change.

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Re: Progressive suspension

Postby CapnDenny1 » Fri Jul 16, 2010 9:03 am

Thanks for the reply.

I wanted to get the 416's, but got no $$$. I bought a set of Progressive springs to go inside the stock Honda shocks for $60 from Bike Bandit and a set of seals. Still waiting for them to arrive.

I built myself a spring compressor, but you can buy the Progressive tool 32-5507 for around $75 and do it pretty easily. I didn't have the $75 either. But I think my creative efforts will get the job done for almost nothing in parts. If it works I'll post a picture of it.

I also did an analysis of the physics of the stock shock. It's a pretty clever design with the oil and air together. It took me a while to understand hwo it worked. But basically the oil is pushed by the damper shaft and that in turn compresses the air. What I determined was that if you had too little oil in the system, then the air spring doesn't increase it's resistance very much as it gets compressed. You start at 65 punds pressure at 50 psi in the shock, and at full compression you only have maybe 90 pounds of resistance, with the shock low on oil. If you put more oil then you start at the same 65 pounds of resistance at 50 psi (The initial force relied solely on teh air pressure.), but when you compressed the spring the resistance would go up much much higher to 3 times the initial resistance, like 200 pounds. So perhaps a lot of older wings may not have weak springs, but only be low on oil. You can't really fix that by increasing the air pressure either. That increses the initial force, but it still doesn't increase as much as it shoudl when compressed.

I posted this on the Classic Goldwings site and one of the guys simply added oil to his bottoming out GL1100. He said it made it stop bottoming out and it rode wonderfully. he even made a video of how he added the oil with the shock still on the bike. He removed the air fiiitn at teh top of the shock and used a syringe. He compressed the shock all the way down somehow, an dthen put the syringe in the hole and as he let up the bike the shock sucked the oil into the hole. I would worry about not having enough air, but he said that when it was almost to the 12 oz value the shock was spitting the oil back at him. Now that is with the shock all the way down, so as you let it up it will fill with air. So it's probably not a bad method.

So if you have a Goldwing with the oil/air shocks an dit bottoms out, you may need new springs, or you may just be low on oil or ATF in your shocks.

I took one of my shock off and have drained it for a few days, and so far at most about 2 or 3 oz of oil have come out. So perhaps mine only needed oil added and I didn't need the new springs. But I haven't heard anything bad about Progressive Suspension parts, so I don't think I wasted my money.

They also sell teh Progressive Suspension dampers to go inside the stock Honda shocks. I found them for $135 somewhere, but once again no $$. I am going on vacation next week, so I need to be a little frugal. I will probably buy those in the fall. Then I will have pretty much a 416 shock for about $200, and they will be air adjustable and look stock.


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Re: Progressive suspension

Postby idjit » Sun Jul 25, 2010 7:20 pm

I though this would be a good thread to post today's experience. I just installed a set of progressive 416's. A while back I replaced my exhaust with "Jardines". I don't have the P/N right now, but it's the ones with the crossover tube. Anyhow...surprise!! The new shocks were so high that the pipes were in the way. The rear axle was right on the pipes, both sides. This wasn't going to work.

The solution was to loosen off the exhaust at the manifolds, loosen the clamps and remove the rear exhaust mount and bring it around to the outside of the rear exhaust mount point. Of course the flange doesn't fit there because the rear foot peg mount is in the way, but the grinder fixed that. I simply ground down the mounting tab on the muffler to fit the angle of the foot peg mount. I also had to whack those tabs a bit with a hammer to bend them the little extra that I needed to get my clearance (before mounted). They bent quite easily and it left no marks. I also needed to tap at the crossover tube to get some distance there as I moved things into place. Then I tightened everything back up. I even got away with not having to replace the crush gaskets at the manifold. The guys at Jardine and Progressive need to talk.

So, the ride... I was looking very comfortably over the windshield as I had hoped. No more bottoming out on bumps. But it felt too firm and my already sore back, from bending over the bike all day, took the crunch. Of course I was trying to hit all those bad bumps that I normally slow for. I had a bit of a rocking horse thing going on. The front shocks were set at 14 and I had the rear at 30. I took the front up to the max of 21 and dropped the read to 15 for my ride to work in the morning. My drive includes a very bumpy road and I used to keep the old shocks at the max both front and back. I hadn't checked the front lately I guess. Progressive must have known I'd need a pretty low pressure cause they give the instructions to defeat it. I'll take that as a sign.

It's some easy to put this thing on the center stand now, but it leans a bit hard on the side stand. -Bob

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