Progressive Upgrade on a GK

[Gary Lich]

After a day of excessive bouncing and wallowing around on the back roads East of Mt. St. Helens last week I am going to quit being so cheap and upgrade my suspension. I read a bunch of posts about progessive springs/shocks but didn't see anything specific on the GK. Any recommendations on progressive fork spring preload length and good rear aftermarket shocks for the GK would be appreciated... (I do a fair amount of two up riding)

[koolaid_kid]

I suggest calling z1 enterprises:

http://www.z1enterprises.com/

Your bike may not be listed on their web site, but the people that answer the phone are very helpful and knowledgeable.

[GS1100GLMLA]

Gary,

I just got done putting on progessive 412-4222C shocks on my 82 GS1100GL. They are perfect. Big difference in handling and smooth ride. I had the original OEM shocks on the bike before. I would highly reccommend them. I found mine on ebay. The supposedly were never used and I got them for half the new price.

[Planecrazy]

Until about a year ago I was riding my 1100G on the OEM airshocks/springs without ever thinking about whether the pressure was dialed in. When Domino and Erika had their sidestand mishap at Galena, I wound up shuttling him to and from the local hospital the day after it happened, and subsequently pumped up what turned out to be NO pressure in the rear!

WOW - what a positive difference it made to put some air in there! The bike was much more squirrelly before the "air." Now it handles MUCH better! I suspect the progressive suspension is probably even better, but for now I'm so much more confident on the OEM units that I don't plan to change them anytime soon.

Regards,

[MissFabulous]

I looked into this a little bit for the GK I have since sold. The forks on the GK are monsters - really unusually wide, and from what I found, Progressives weren't available/compatible with them. I believe it was Grandpa or Redman or dpep who suggested swapping out the front end with something else, and now I can't remember what. Sorry that isn't much help, but I'd PM one of those guys

[Grandpa]

Correct, MissFabulous, about the GK forks' diameter being larger than the 850G and 1100G. This is true of all GK's, regardless of year. Fitting with Progressive updates may be a problem.

Since the GK forks have a larger diameter, the triple tree must therefore be different. Not only is each of the forks of a larger diameter, but they're also further apart from each other.

Fortunately, a regular "G" triple tree and regular forks will also fit the GK. I replaced my stock GK triple tree and forks when Bambi messed them up 6 years ago; I installed a GS850G triple tree and set of forks on the GK, and they fit perfectly.

If you do that, the fender must be replaced as well, since the GK fender is wider than the G.

So, I have a GK with an 850 front end. It works.

[Planecrazy]

Nick,

I learn something new about the difference between a "G" and a "GK" almost every time you post! I didn't realize that there were as many differences as there are. You ought to start a separate thread detailing all the differences for anyone who's wondering about parts interchangeability!

By the way, did you notice a significant difference in the handling between the wider GK forks and the replacements?

Regards,

[Grandpa]

No difference whatsoever. I have a Windjammer IV on the GK, and the bike handles as well as it ever did.

Most of the parts on the 1100G and the GK are the same, or at least interchangeable. There's also the minute differences among the 3 years of the GK.

[willie]

I'm another GK owner who would like to know the differences between the GK and G models. I seem to be getting into quite a project "updating" my GK. I've considered putting a different front end on so I can improve the braking and overall handling. Now that I've learned the forks are bigger and wider on the GK, looks like it'd make more sense to swap out the calipers (anything else fit?) and install a forkbrace.
Thanks,
Willie in TN

[Grandpa]

I doubt if you'll find a fork brace that will fit the GK. Actually, with forks that large, I don't think you need a fork brace at all.

The front calipers on all large GS shafties, other than the 79 850, are interchangeable. Even these 79 850 calipers can be replaced by the newer ones, just by bolting them on; chances are it's the same part number for all the rectangular calipers. The wheels on the 82 and 83 850G, 82 and 83 1100G, and all three GK years (82, 83, and 84) are also identical. The only difference is the 16-in rear wheel on the GK (and on the "L" models, except the 80). A 16-in rear wheel will go on the 850G and 1100G, and a 17-in wheel will go on a GK.

The calipers on the GK are fastened to the GK forks by longer bolts. That's why these calipers are good for both the G and GK. The brake discs line up perfectly, the same on both bikes.

The GK frame is different from the G frame in that the GK fairing has to be bolted onto the frame. Therefore, the GK frame must have tapped bolt holes for the fasteners. The 1100G frame is exactly the same as the 850G frame for 82 and 83, as are the forks and triple tree, fender, caliper, and wheels.

The most efficient and cost-effective way to improve braking on G and GK is to go to braided brake lines, ensure that the brake fluid is fresh and clean, and that the calipers work 100%. You'll be surprised at how much difference this will make.

All large (850, 1000, and 1100) GS shafties are wonderful handlers as they are. Think twice before making any radical changes, as these will probably yield marginal results, even after much time and money invested. Keep in mind these GS frames date back to 1970's design, and aren't anywhere as stiff as modern frames are. The law of diminishing returns takes over for me.

I'm willing to live with the limitations of my GK in the power, handling, and braking departments, knowing that it's still a 23-year-old machine that was conceived, essentially, 30 years ago. I've made improvements in the areas that can inexpensively, in time and money, be improved upon.

96,000 miles on my GK in a little less than 8 years, and I go wherever the Gold Wings and BMW's and ....... go (I'm the one who usually takes them there, because I know the roads). I smile when I think of all the money and time I'm saving while I enjoy the wonderful ride that my GK continues to give me, and the money that remains in my pocket every month. I also ride often and hard, which explains why the GK has lasted so long; nothing worse than letting the darn thing sit idle in the garage. Ride hard, ride often, and ride happy.

[Gary Lich]

My gut said this wasn't going to be simple... however, the Progessive site does list different fork spring part #s for the GK, G, and L models so that is somewhat encouraging, but needs further research on whether they are actually available...

[Grandpa]

My gut said this wasn't going to be simple... however, the Progessive site does list different fork spring part #s for the GK, G, and L models so that is somewhat encouraging, but needs further research on whether they are actually available...

That's certainly a good sign. Let us know how things turn out.

[willie]

Excellent response! Thank you very much. I agree that its a great bike, even if it was designed a few decades ago. When I enquired about replacing the calipers I was thinking more along the lines of calipers off a newer Suz sportbike. Instead, I'll go with braided lines and will rebuild the calipers.
BTW, were you able to use the factory fairing supports for the Vetter? I think the Windjammer looks alot better than the Suz fairing. Of course, that my personal opinion.
Thanks again,
Willie in TN

[Grandpa]

Reason I replaced the stock GK fairing with the Windjammer: I crashed into a deer and destroyed both the deer and the fairing. In other words, the GK fairing got the deer right in the gut. We ate the deer; ground venison is good for chili and spaghetti sauce.

If the stock GK fairing had not gutted that deer, I'd still be riding with the GK fairing on. It's a good fairing which works fine and looks good. I also like the Windjammer; it has lots more room for storage than the GK fairing. Yet I like the GK fairings little pocket on the right-hand side. Vetter Windjammer parts are still available through eBay; I replaced the left turn signal lens on the Jammer some months ago, real cheap.

I bought the Windjammer for $100 and then bought the mounting bracket for it. I used the bolt holes and some 3 common metal brackets and jury-rigged the mounting bracket to the frame. Not pretty, but it works. I have lowers on my Windjammer, so one can't see the jury-rigging from an ordinary angle.

[ta473]

springs

progressives are avaible for a gk. ibought a set for around 50.00 new. if you want i can find the site and post it.and yes it is a whole new bike with good springs in the frount and rear.