1981 GS450 shocks

[uncletom]

Last friday I bought my '81 GS450. Lovely bike, just that the previous owner was a bit short, I noticed that the shocks are 280mm length, which puts the rear wheel too close, almost inside the fender.

Any idea what the original length is supposed to be? I've gathered somewhere between 310-340 mm. Is that right?

 

[Steve]

Not sure about the 450 in particular, but most of the GS line used 330mm shocks.

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[sam000lee]

That's a shame because those Hagons look nice

 

[Gorminrider]

yes...translates to 12" to 13" long off the bike. Here's a stock photo of a gsx400E (identical to 450E except engine)...it depends somewhat on the model. The 450L and the 450T will have slightly shorter shocks and fatter tires.

I'd have to go out and look at mine to see if it has the clearance shown in this stock photo below...springs sag if stored if the weight is always on them but these are pretty light motorcycles too....

 

[uncletom]

Thanks for your input boys. And is there any particular brand I should get, or will most 330mm length, and 12mm mount hole diam shock do?

For instance the preload on springs, does it vary alot between shocks?

 

[Gorminrider]

I have a set from a Honda on my GSX400T now....so, if it fits , it's worth a try. On my GSX400 E (like your450E but red) I have the shocks it came with but they are not "progressively wound" springs like yours(progressive wound is when the coils are close together at one end)All my shocks work best for me with ONE notch preset but I only weigh 150#...
add: more preset, longer shocks will probably ease putting the bike on centre-stand...which is suprising hard on these apparently small bikes-almost the same as a GS650..Honda and Kawasaki I have are much easier...I think they used the same centrestand throughout models but I haven't measured....

As to replacements...it's something I've researched ....but particularly Progressive brand...and ebay cheapies- be aware of the damper rod size (the shiny rod you see going into the shock) it need be the same diameter or possibly larger. ... the Progressive shocks have some appeal in that you can reuse your springs if they are the correct length to suit the (fully)extended shock-you will need to compare diameters of spring "thickness" and relaxed height to the Progressive ...the OEM Showa units are fairly easy to dissassemble to spring and shock, just like cars...squeeze the springs and remove the cap.
Hagons are popular too. There is a chart that shows replacements for your bike.."33012" or "33013" and then a I'm assuming the length is the last two numbers...Hagons have a stainless steel option I think...

It gets complicated comparing but you need your length, your shock's mount type, the bushing size required for your bolt size, some idea of your GVRW etc...

in the end for Progessive I came up with this that I never acted on:
"Progressive OEM#: 12-1202B 13" length (no springs )" for what it's worth!

 

[uncletom]

Thanks Gormin for your elaborate lesson. Yes, that center stand is a pain, I managed to hurt both of my shins, each at a time, trying to lever the bike up. I guess I need more practice on that, I'm sure there's a youtube video on the subject.

I'm not too keen on disassembling, or assembling any shocks to mix and match springs, my current ones are 280mm and on their loosest setting I've noticed the spring can be moved sideways, so the spring isn't that compressed which means it won't stretch more.

And I understand that progressive springs are prefered to the linear wound springs? I gather they perform differently depending on the load and compression, like soft at first, then gradually harder. Is that right? But looking at old adverts for GS450 it seems Suzuki didn't use progressive springs back then, or ?

Then, I seem to have found Hagons on ebay that will retro fit my GS450, also I found cheaper alternatives which look great. Like these :

https://www.ebay.co.uk/itm/universa...-motorcycles-340-mm-black-spring/264813279091

 

[Gorminrider]

yes, sorry, I tend to fill the bucket with stuff on the chance it helps...

I gather they perform differently depending on the load and compression, like soft at first, then gradually harder. Is that right?

Yes, as the close windings compress, they lock up and don't compress further...personally, I prefer linear wound based on the examples I ride. The progressive wound seem like some sort of trick to get a suitable ride from a shorter shock length but it's just a guess. No doubt there's a body of info online.

looking at old adverts for GS450 it seems Suzuki didn't use progressive springs back then, or ?

Not sure but my third-hand '81 GSX400T came with a set. Someone might have changed from OEM - a bit shorter than 13"....To ride, they are ...ok, but give a harder ride than the Honda ones i swapped in.... and being a little shorter made the centrestand that much harder.

The linked cheapie ebay ones look ok. I want you to buy a set and tell us all how they are! Emgo also offers budget replacement shocks. I'd want to be sure they have the same shaft size ( a 125 or 250cc can have skinnier shocks) and that the bushing diameters suit.

On ebay, he has good feedback but I like to read some to see if there's any comments specifically about the shocks...

did I mention the OEM ones that came with the bikes were Showa? as are the front forks...the labels peel off.

 

[Steve]

Good luck with those cheap eBay specials. :-\\\

My son's 1000G came with a pair of them. The spring rate is probably pretty close for my son, who has an enhanced gravitational attraction, but the damping is set up for a Mack truck. When there is also a passenger on the bike, the ride smoothes out quite nicely, but when riding solo, there may as well be solid struts in place.

.

 

[uncletom]

Well, I bought a couple of 330 mm Hagon from Germany. Here they are:

https://www.ebay.com/itm/Stoßdämpfe...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

I would really love to buy several sets of various brands, length 330-340 mm, with various springs, to try out on my Suzuki. ?hlins would be great if tuned to the exact weight of my bike with me on it, know they make digitally controlled real-time adjustable shocks. Though I fear that ?hlins would be very expensive, and not fit my 1981 Suzuki very well stylewise. What brands did the japanese motorcycle manufacturers use back then?

 

[Grimly]

What brands did the japanese motorcycle manufacturers use back then?

Showa on just about everything leaving the factory, as far as I could see.
10mile shocks. It took 10 miles to realise they were crap.