Low Speed Bar wobble..?

[KCKBMOA]

I've had this '93 K1100RS now 4 yrs, and do mostly work commute, 50mi each way. I have a "casual" detour that takes me along the old Hwy 1 at a 45 MPH limit. I usually set the throttle, and use this 10min leg to sit up, and rest the right arm. The other day, as I did this, the bars did a wiggle. I was surpised, and stopped it with light hand pressure, but holding straight with 2 fingers allows this 1" wiggle to come back. Now this is that same road, same rider, same speed, and only at low speed. The bike has always worn the left side of the tires quicker, and pulls to the right. This issue has been beat to death with no real answer on this forum before, but the wiggle is new. Something changed, any ideas? KC

[godzilla]

My K100 was doing this last year. The problem turned out to be a worn out steering head bearing. To troubleshoot, my wrench guy put her on the centerstand, tilted her back on the rear wheel and moved the bars side-to-side. You could feel a little notchy kind of thing. He replaced the bearing and that fixed the problem. I can take my hands off the bars at low speed and she is stable as a rock now.

He had me come back between 600 and 800 miles to check the torque, by the way. Apparently they can loosen up a bit after break in. Mine was spot on, so no readjustment needed.

Easy thing to check; not sure how hard they are to change. Although I detected the problem mid-way through the Summer riding season, the wrench said that unless it gets noticebly worse, I would be OK until the major service we had planned over the winter.

He was right, as usual.

[johnpeter]

I'd check the steering head bearings.
May need replacing or just repacking and resetting the preload.
These bikes use tapered roller bearings and they are slightly preloaded unlike ball bearings that have little or no preload.

There is a tutorial on steering head bearing here http://www.ibmwr.org/ktech.shtml

You might try adjusting them first and if that clears the issue, then repack/replace and readjust. These bearing are common and can be bought just about anywhere.

Note: Any notchieness or rough spots when preloading the old bearing means they MUST be replaced.

That's my only guess because of the three non-German bikes I've had that developed what you speak of, it was the streening head bearings. On the old Suzuki GS750 I was able to replace ball with tapered roller, made a real difference.

[KCKBMOA]

I'll check that today. Certainly makes sense that with the pull issue, the sterring would want to return to the "notch", and then get pulled out again. KC

[KCKBMOA]

Well, that was a no-brainer. I weighted the back of the bike so the front tire was off the floor. Any movement off center returns to a definate home, or worn spot in the bearing. So it's time to replace that .... KC

[johnpeter]

Well, that was a no-brainer. I weighted the back of the bike so the front tire was off the floor. Any movement off center returns to a definate home, or worn spot in the bearing. So it's time to replace that .... KC

Those can be sourced from any bearing house.
I would stay away from bearings made in India or China because most of those are produced on old tooling that was bought out of the EU or USA.