Need Help. Rig has a side by side motion

I think I might make sure all your mounts are secure. A loose or broken mount could cause that kind of motion. Also check your tire pressure. I can always tell when my tire is low when the rig starts to wallow.

Some rigs will do a hobby horse type dance if the rear shock is too soft. This is evident when shifting gears. It also happens when crossing irregularites in the road surface as the sidecar wheel hits a bump and weight transfers to the rear bike suspension. Due to the wheel lead on the rig this can get a strange feeling going. I may be totally off base as far as your rig is concerned though.
Where are you loacted? Maybe someone here is near you and can do a test run for you?

worth checking sidecar wheel balance i had same problem after changing sidecar tyre, fitter had balanced wheel but had stuck weights 180deg out so sidecar wheel was bouncing it took me ages to find cos i ruled out sidecar wheel cos it had been fited by a profesional.

Hi Rich: Past experiences with a K75RT and K100RS has shown they are sensative to proper setting(s) on the rear shock and would "wallow" as a two-wheeler if improper. Might also check the toe-in as we had a rig with excessive toe-in pushing the sidecar into a too softly sprung tug until the tug would push back on the car and thus, the whole rig "wallowed."

mine did that with weak rear shocks also, changed to stiffer pre-set..I also softened tire pressure on the car wheel to be more forgiving,..problem corrected , my 2 cents, crawf.

You seem to going thru alot of tyre's, is there a wear problem? If there is you're setting's maybe be wrong.

Also, have you done anything to the steering head bearing's (tighten/loosen)?

Safe riding Karl.

Hello

Have you got a steering damper on it.

Barry

Thanks for the suggestions. Here is a bit more info: The rear shoch is new. It is a momo-shoch. Unfortunately it has no adjustment. The front wheel has a new stearing dampner. I am changing the tires only to replace radial tires with belted ones for stiffer sidewalls. There is an adjuster on the sidecar. It raises and lowers the sidecar. I have tryed it in several positions. No difference. I don't plan to take it accross country. It is for local riding. So I am not worried about tire wear only stability.

I am going to try a little lower pressure in the sidecar tire. Then look at a stiffer shoch for the rear wheel.

Any suggestion on how to set the level of the sidecar with and without a passenger. I have been setting it to a point that feels level to me sitting on the bike.

Thanks,

Richard
Ranger, Texas
K75 Sidecar Rig

Rich, are you sure the K75 shock is not adjustable? I ask as I don't recall ever seeing a K-bike shock without an adjustment spring pre-load.

I don't know but there are those that do, is it possible that the toe in is off and it's actually toed out and the bike/sidecar is trying to center it's self.