Rear wheel hop

[kevinkdx]

I have a 93 KDX 250 that has a rear wheel hop problem. No matter if it is a smooth surface like blacktop or dirt and even if there are no bumps my back tire just goes up and down. I just resently tore the swingarm apart and put all new bearings and grease in and i had this problem before that so i know this isn't the cause so i was thinking if it was a bad shock or shock oil, which i don't think has ever been changed. or just a problem with the way i have things dialed in. any help is appreciated.

 

[shockdoc]

Sounds like your shock seal is bad & you have lost some oil & damping. If it's acting like a pogo stick you need to get it rebuilt.



doc

 

[Glitch]

Why would the shock act as a pogo stick on flat surface? I was thinking if it only did that hop on braking pumps, or on rough conditions, then maybe you would need to decrease your rebound, or increase your damping(I think). But since it happens on flat black top, I would suspect maybe an unbalanced rim. It could be so out of wack, or maybe have a flat spot, that when you go, it just bounces you. So when your bike is on a stand, spin the rear tire and see if it wobbles or moves up or down, etc. If it does, it needs to be trued. So check out the tire being untrue first.

 

[DEANSFASTWAY]

Get your shock checked by someone competent so you dont need to make a trip to the Emergency Room . That oils got to be puked out by now anyway. If its still good maybe they can help you set it up correctly.

 

[JasonWho]

If it happens on blacktop, I would definitely check for wheel problems. Since you don't know if it has been serviced, then that may be a great indicator that it DOES need to be serviced.

That reminds me of a 1984 KX125 I once worked on. Something was definitely wrong with the shock. It was pure spring. While riding on flat ground, if you pushed down hard on the pegs and then quickly unweighted them, you could get the rear wheel to come up off the ground.

Hope this helps,
JasonWho