Author Topic: Rear Suspension Upgrades  (Read 12170 times)

Offline elvin315

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Rear Suspension Upgrades
« on: May 18, 2011, 10:44:57 pm »
Connie's rear shock is not rebuildable so there is only one option when it comes to improving it. Changing the original shock oil. It comes loaded with 10 weight which provides a "plush" ride. The oil viscosity determines the shock's compression rate and the only way to change it is to use thicker or lighter oil. Refilling it with 15 weight improves the ride and helps the rear suspension track better over rough surfaces. It's a homegrown solution. Kawasaki doesn't outline it in the shop manual. Murph has a shock re-oil kit custom made for this on his site. The rebound rate is controlled by the 4 position adjuster (1-4/soft-firm). It's settings outlined in the owners manual (pg. 88-89) but the chart they supply is near useless. Simply put: The heavier the load, the rougher the road, the higher the speed, the more the rebound damping you need. The last item to cover is preload. Being an air shock care must be taken when increasing its pressure. Use a low volume hand pump tp prevent blowing the oil seal. The range is 14-50 psi. It sets the rear sag and in general the more weight you carry, the higher the pressure. Remember, too much air will increase the ride height and affect your reach to the ground.

A step up from stock but still cheaper than aftermarket would be a shock from another Kawasaki. There may be others but the ZZR1200's shock absorber will fit the Concours with minor trimming of the Concours' upper bushing and using the ZZR's lower rocker. It has a remote preload adjuster as well as rebound damping adjustments.

Per Shaun Forgacs: Installed the ZZR rear shock last night. The upper bushing is 2mm wider so i had to trim it and I used the ZZR lower bushing in place of the stock connie bolt. Other than that it was a bolt in mod. Got it off e-bay from It has a remote preload as well as rebound damping adjustments. I got it to improve 2 up riding and it is much better than the stocker for that. Solo I have the preload set to 2 and the damping on 3. The damping is a little to much so I am going to drop it down to 1. It makes the bike feel much smoother. It also raised the rear about a half inch which is perfect for me. I need as much lean angle as I can get.

Per Wayne Roberson: First the adjuster should fit even with a Cruise Control installed. It's not very big and has a good length of cable to play with. Second, used everything stock except the one bushing from the zzr linkage to bolt the bottom end of the shock. I did a very minimal grind of the upper shock bushing so it fit cleanly, maybe 1/16 inch. I don't know if mine was just tight clearance wise so I ground it to fit, not wanting to force it into the upper mount. Only drawback I can see is losing the grease fitting on the lower shock mount however it may not be necessary now with the bushing supporting the bolt still carried by the bearings in the rocker arm. Clean and easy to do. Put more miles on it today and like the feel seems more planted than before and handles road imperfections better. Pictures:

George Young's excellent ZZR1200 Shock Install:

It's recently been discovered that the rear shock from the Concours 14 will also fit with minor alteration. I don't have the details but searching the forum will reveal will tell you more.

Next up is an aftermarket shock absorber. The following manufacturers build shocks for the Concours. Review the sites and consult the vendors for more details:

Progressive Suspensions:
Standard 420 Series  :  420-1016

Works Performance:
DuraSport & UltraSport
Note: page 6

GTR 1000 86 - 04  Type 40 Emulsion KA10-003R

Wilbers/US Importer:

Hagon Products:

TechnoFlex (Netherlands):
ZG/GTR 86-93 #55311-111-889
ZG/GTR 94-01 #55311-111-890

The following aren't shock upgrades but fall under the category of rear suspension modifications. Norm Soucy's Unitrak rocker lowers the rear but if it improves the ride or handling, I couldn't say. There are no swingarm braces either. Considering how much a fork brace improves things up front I can't help but wonder what a swingarm brace could do out back. Someone with welding skill could probably make one, remembering to design it so it doesn't interfere with the swingarm's arc and allows tire removal.

Technically not a suspension item but it's the crowning touch for the rear of your Connie. A wider 17 inch rear wheel. It allows you to choose from a wider assortment of tires than are currently available for the Concours. Being wider it also creates a larger contact patch  under the rear tire for better traction and more confidence in the turns.  There are currently 3 ways to acomplish this. The first is a Concours rear wheel (any model year) modified by Kosman Specialties. They keep the Concours' hub and spokes and weld it to a wider 17" rim. This way the wheel looks and mounts like stock. Of course this isn't cheap but it's worth the money.

The other is a homegrown upgrade and that is using a rear wheel from the Kawasaki Mean Streak/Suzuki Marauder muscle cruiser. Not only is the wheel 17 inches in diameter and wider than stock, but the rear hubs use the exact same cush drive so they mate together perfectly with the Concours' final drive. Modifications have to be made to the brake because the bikes use different components and mount differently but several owners have done it with good results.

I mention a third option but so far I've only seen one example and the bike's owner is lost on the information superhighway so I can't answer any questions regarding how to do it. This owner had his Concours' rear hub welded to the spokes and rim of a Suzuki GSXR. Just like with the Kosman wheel this allows use of the stock Concours rear brake system without modifications.
« Last Edit: June 06, 2016, 06:02:43 pm by elvin315 »