Bike: 2004 Kawasaki KX125 Funny how there's no legit trail or MX section of ADV so I have to use the old school 2t section to post this. Bike is all stock and I don't really use it for MX, so the suspension is super stiff for me. In particular, the rear shock. I'm also a light weight at around 130lbs. Anyone have any recommendations for a better shock suited for trail riding/single track? Maybe even just a lighter spring would be nice. I know I should consider a different bike but this one was cheap, available, easy to maintain and has the right power for my size.
You might get your answer here but you would definitely get one here: http://www.thumpertalk.com/forum/76-kawasaki-2-stroke/ I'm betting just a spring and maybe a revalve would do the trick. I'm on the previous platform though (2000 kx250) so I don't know the details on that bike.
Have a look on the Racetech website and see what springs they offer for your weight and bike, if there is a suitable set of springs (front and rear) it may be worth simply changing those, unfortunately once you get into tuning the complete suspension it gets expensive fast so pick your battles.
MX bikes need revalving front and rear for trail riding, very harsh on roots and rocks. Any good suspension shop can do the job.
Backed 100% off and still bucks me like a bronco. I've heard these bikes can be over dampened and under sprung so I may be looking in the wrong direction. Luckily, I have Highland Park here in GA and their suspension guy is top notch, so I may have him check it out this Sunday.
Those shocks should be adjustable for what you need it to do. Backing off the pre-load just lowers the back of the bike and has no affect on the suspension action itself. You need the pre-load set to get the correct "sag" in the suspension for the bike to turn. If it is too light and the bike sits too low in the back, the front end will push and slide out. The bike should "sag" about an inch under its own weight and about 3" when you are on it in full gear. Start here. Once the sag is set, you can move to the clickers. Hit the interwebs to see what your stock clicker settings should be. You may find that they are way off and returning to stock will help immensely. You will find the info will be listed as say..... 12 clicks out on compression and 8 clicks out on rebound or something like that. To get to that figure, turn each clicker all the way "in" clockwise until it stops. Then turn it back out the required number of clicks. You'll feel the clicks with a screwdriver. If the bike is "bucking" as you say, slow down the rebound adjustment by turning it "in" or clockwise. The rebound is the adjustment at the bottom of the shock near the linkage. Its hard to get to, but rarely needs to be adjusted more than a couple of clicks. Try going in 2 clicks at a time until you are comfortable. As you turn it in, the valving will slow down the return of the rear tire to the ground. Set it too light and the back end will hop and kick and try to buck you off. Once it quits kicking, move on to the compression. This is the clicker at the top of the shock near the reservoir. Its easy to get to and you can change it all you want. Lots of rocks in the trail, turn it out or clockwise to allow it to compress easier. A smoother trail with lots of whoops, turn the clicker in to slow it down and not bottom. Both clickers use the same premise - in the slow it down, and out to speed it up. 130lbs isn't that far off of the base setting for a 125. Those bikes are usually for smaller folks, either coming up from the 85's, or too small for a 250. I would think the springs would be pretty close. Once you have set the sag and played with the clickers on both sides, if you still can't get it where you like, then take it to a pro. There are infinite adjustments on the newer suspension. Taking the time to set it up is half the battle.
