various shock directions

Information and questions on GL1500 Goldwings (1988-2000)
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Motorcycle: 1997 Goldwing

various shock directions

Postby Dogsled » Wed Jul 16, 2014 6:36 pm

I'm at a crossroads that has several directions and several opinions on each. I put a set of Progressive 412's on my bike MUCH to my dismay. I bought them from Dennis Kirk. We do have a bad ass hot bike shop in town that uses progressives and say they BUY RIGHT FROM THEM AND GIVE THEM THE DESIRED RIDE HEIGHT they want........not just some stock jack you get from Dennis Kirk. going from adjustable air ride that even at the lightest weight have mucho little compression.....this is not gonna make it.

i did a bit of research on how to lower the bike to AKA low bagger feel and it all comes down to cutting the springs......pros and cons on this are rampant. I think the removal of some coil is not going to affect anything.
here is what i've gone thru.
Run one shock/ spring
run one shock spring and possibly stich a shock on the other side
cutting springs I heard this is a back door attackto solving the situation and could createmissues of a rough ride..maybe/maybe not
looking for an olf let of OEM air shocks and leave the one progressive in. Hmmmm best solution yet. The first thing I would need to do is to run just one shock and see what type suspension I had.
Being the rear runs on a mono suspension I would like some opinion on how running one shock (if it carries all the weight) can affect handling. Now I don't want suposition, I want some guy thet tried to do this and has facts why it won't work.
Tomorrow i'm going to start (evenn against logic) start cutting the springs to my desired height and still have excellent handling.

"Fight until hell freezes over, then fight on the ice"

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Re: various shock directions

Postby WingAdmin » Thu Jul 17, 2014 12:12 pm

The stock bike does run on one spring, but two shocks. One is used for height adjustment (air), the other for support and rebound damping. So it's not quite the same as having just one on one side.

That said, cutting the spring will lower the shock, but make it less capable of absorbing bumps. Here's what I wrote on this before:


I put Progressive 416's (air adjustable) shocks on both my GL1100 and GL1500. Both were raised up about an inch or so with the new shocks installed - the 1100 was raised up more than the 1500, I assume due to the 30+ year old springs that were replaced.

Ride height and stiffness are not necessarily linked - however, in some cases they are (necessarily). On my wife's PC800, I intentionally lowered it about an inch (front and rear) by putting shorter shocks (rear) and springs (front) in. On the rear, due to the reduced suspension travel, I had to select springs with a higher spring rate (stiffer) in order to prevent the bike from bottoming out the suspension on large bumps. As a result, the suspension is stiffer than the OEM suspension.

You can easily select a shock with an increased spring rate that is the exact same height as a shock with a lower spring rate when the same amount of weight is applied. This is the spring's load rate - the amount of weight the spring is designed to carry when compressed a given amount. So by varying spring rate and load rate, as well as overall spring length, you can vary both ride height and compliance (stiffness) independently of one another - within limits. At some point, you have to increase the spring rate to compensate for reduced suspension travel to avoid bottoming out, as I did on the PC800. Progressive type springs can help with this, as the spring rate varies depending on the amount of deflection - it's more compliant at full extension, giving a softer ride, and stiffer as you compress it more and more, to prevent bottoming out.

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Joined: Tue Dec 13, 2011 4:27 pm
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Motorcycle: 1997 Goldwing

Re: various shock directions

Postby Dogsled » Mon Jul 21, 2014 2:50 pm

I got a grip on how shocks/springs work and the ramifications of cutting the springs mean after alot of reading (and your replies) BUT, tell me this, if I were to have a good air shock that was oem to the bike and just replaced the one spring, wouldn't that pretty much bring the bike back to original suspension. Progressive selling only either dual spring or dual air shocks isn't what the bike was designed for. Problem is, you can't buy just one.
Had I just changed the original setup with one manual spring I would have gotten the estimated 1" higher ride you were speaking of being the difference between the old spring and new spring's capabilities.
Progressive isn't giving you the best of options here as far as I can see making you replace (or at least make you purchase) BOTH springs of either air or manual.
Technically if I could find a good air shock and stick that on it would/should bring me back to original with one new spring to sell.
What's you opinion of this analogy?
"Fight until hell freezes over, then fight on the ice"

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