ASK THE MXPERTS: GOING BACK TO THE 1997 KX250

Dear MXA,
I am trying to find out the suspension and chassis settings you wound up with for the 1997 Kawasaki KX250. Have been trying to find them on the internet with no luck.

No problem. Here is exactly what we thought of the 1997 Kawasaki KX250 suspension from the February 1997 issue.

Forks: “We can’t live with the stock KX250 forks. They are ill-matched to the rest of the bike. In general, they ruin the handling package and, in specific, they drop down into their stroke and cause the bike to stinkbug. They are wrong! However, they are easily fixed. For reasons unknown to man, Kawasaki‚’s test riders have spec’ed 0.40 kg/mm fork springs for the last couple years. Too soft. We swapped to a stiffer set of 0.42 fork springs and the improvement was dramatic.”

Shock:
“There was a time when Kawasaki held sway over the suspension crowd with incredible showroom stock settings. Then, they lost their way. The previously flawless KX suspension became atrocious. You’ll be glad to hear that they bought a road map and are back on the right track. The 1997 KX250 rear suspension is the best on the track. Roll it out of the showroom, set the sag, and live happily ever after.

The stock spring rate is well mated to a wide range of riders, but anyone pushing two big ones might invest in the next stiffest shock spring. If you are a 200 pounder, use free sag to judge whether or not you need stiffer coils. When you have the shock set up with 95mm of sag (with you on the bike), get off and lift the rear end up by the back fender. As a rule of thumb, for big bikes static sag should be between 30mm and 40mm. If the static sag is more than the recommended 40mm, your spring may be too stiff for your weight. In this case, the spring is not compressed enough to allow the suspension to extend far enough on its own. A spring that’s too firm does not allow the rear tire to hook up under acceleration and transmits more bump energy into the rider.

If the static sag is less than 30mm in the rear, the spring may be too soft for your weight. In this case, the spring requires so much preload to achieve the proper race sag that it makes the rear suspension closer to being topped out. As a result, the weight transfer is incorrect and the rear end tops out under even light braking into corners or down hills and may feel loose and wallowy, especially when accelerating in flatter turns. If the shock has some free play in it (at least 30mm but less than 40mm) then you can live with the stock spring; however, if the rear of the bike is topped out, hoof it down to your dealer for a stiffer shock spring. If you own a 1997 KX250, you have the best rear suspension of the year.

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