What the Fork is Going On?!

[Kodak]

Hey all,

Intro thread is soon to come once I upload all the images! I acquired my first bike, 1980 Suzuki Gs850G with extras, and am in the process of going through the basics outlined in BikeCliffs website. I'm currently working on the fork seals and changing out that god forsaken smell of fork oil. I notice one of my forks at the end of the tube doesn't look like the other one which does look like the one in the fork seal replacement guide from BikeCliffs website. Additionally I noticed this fork had an internal metal ring within the fork seal which I had to cut out. Am I dealing with two different fork models and is this a problemo??
Edit: The forks are the same length, same spring length, and seemingly same external design

 

[hillsy]

The fork with the bush is probably from a later model GS. Not sure which models / when exactly they started using them but my 84 750EF and 85 1150 both had forks with the bushes.

I'd guess the PO changed it out because the old fork was bent or pitted. A lot of the GS's had 37mm forks so changing them around was pretty easy.

 

[Kodak]

The bike came with an extra set of forks, I did notice they had some surface rust, but I'll check for how true they are tonight. I'm guessing the advice would be to put the proper fork tube in. Or is this a setup that can work? I can't see how it wouldn't effect suspension in some way.

 

[Guest]

The fork with the bush is probably from a later model GS. Not sure which models / when exactly they started using them but my 84 750EF and 85 1150 both had forks with the bushes.

All of the 16 valve 1100's (1980 on) use a bushing on the bottom of the fork leg as well.


Mark

 

[Kodak]

So are they interchangeable and in this case any different to the 1980 GS850 fork style?

All of the 16 valve 1100's (1980 on) use a bushing on the bottom of the fork leg as well.


Mark

 

[Guest]

So are they interchangeable and in this case any different to the 1980 GS850 fork style?

Doesn't look like it. According to Partzilla the 1980 850 fork tube is only used on the 79-81 850G and 1000G: http://www.partzilla.com/parts/detail/suzuki/SP-51110-45100.html

The 82-83 1100E fork is different than the 80-81 fork and none of them are the same part number. As hillsy says, there were a lot of 37mm forks and it may be hard to pin down which one you have there. If you use partzilla you can do some cross checking and find out what part numbers span what years and models, but that is all I have.


Mark

 

[londonboards]

I would say that they would both operate in the same manner and that there would be no problem using the set up as is.

That extra metal ring is a replaceable bush that presumably was added to later models to improve the wear characteristics of the fork leg.

 

[portdave]

I have some forks for an 850 if you need some or one.

 

[bonanzadave]

The 82-83 1100E fork is different than the 80-81 fork and none of them are the same part number.

Right. 82E-83E's have the damping adjusters and the anti-dive units. The left fork in your first pic is not a 82E or 83E

 

[Kodak]

Right. 82E-83E's have the damping adjusters and the anti-dive units. The left fork in your first pic is not a 82E or 83E

So what I'm working with is an 80-81 1100 fork? Might have to find its match, do people successfully run 1100 forks on 850 frames? Seeing as they are the same diameter and length, is it safe to assume the upgrade in bushing design was the only important difference?

I would say that they would both operate in the same manner and that there would be no problem using the set up as is.

That extra metal ring is a replaceable bush that presumably was added to later models to improve the wear characteristics of the fork leg.

​

I suppose that the previous owner didn't notice an issue! After I take the rust of the other set of forks which I know to be 850 forks and see their condition I will end up ditching the 1100 fork.

 

[Grimly]

​

I suppose that the previous owner didn't notice an issue!

Just check the total uncompressed length and compare. I nearly got caught out by making an assumption that GS1000 legs were the same as GS850, but the 1000 ones are ~17mm shorter. It worked out ok, though. If you're lucky, the 1100 legs might be overall the same length as the 850. If they are, it gives me something to look for. I will watch this thread with interest.
Regarding the Left to Right differences on your bike as you got it from the PO, it probably functioned fine. After all, some makers have been known to fit odd match legs from side to side and nobody seemed to notice. Rebound damping only on one side, that kind of thing. If the fork brace is stout enough it would work ok, but personally I would try to keep them matched as close as reasonably possible. Given the imperfections of design of the basic telescopic fork, it's a wonder it works at all and doesn't spit people off into the scenery more often.