In my opinion the rear suspension is the weakest link on the Versys. The front needs work but for sure the rear wheel does not handle bumps very well. Kawasaki said:
Its suspension offers the next level in sophistication: an advanced Showa rear shock featuring a free piston and two-stage damping valves for progressive compression damping which firms significantly as the shock moves through its stroke. This allows a longer wheel travel with a feel that is initially soft like a dual sport, but firms to near sportbike levels as suspension loads escalate. Of course, this advanced shock is fully-adjustable and connected to a beautiful aluminum gull-wing swingarm that is longer than average, thanks to a short/compact engine and chassis.
The above quote refers to two-stage damping which would indicate that the shock has position sensitive damping. This would make sense if the spring is straight rate, since there is no linkage to introduce a rising rate of resistive force as the swingarm compresses through its travel.
So considering that the shock performs ok (doesn't seem unsafe unless you hit some washboard in a turn), we would want to make sure that any replacement suspension component would perform at least as well as stock.
I think the options for after market improvement are numerous. I think the list of possible changes might look like this (from least expensive):
- For 1up riding a lighter rate spring or possibly slightly progressive.
- Re-valving the stock shock with proper straight rate spring
- Racetech goldvalve stock shock
- Hyperpro, Penske, Elka, Ohlins, WP, ... complete shock replacement
The concern I would have about a complete replacement would be that there is sufficient bottoming resistance without using an excessively stiff spring. I believe the stock shock suffers from two stiff of spring causing rear wheel deflection over small bumps.
A linkless rear suspension would require internal position sensitive damping or external progressively wound spring or both to achieve the proper performance.
Since most aftermarket shocks are priced without the spring it would be interesting to see what each manufacturer of shock recommends for the their spring rate and whether it is progressive or not.
I hope to take my shock off soon and measure the spring. It will be important to know the rate and how much preload is set on the lightest setting in order to select a proper aftermarket spring.