weaving

[Soreass]

I'm looking at a 1992 R100GS PD, and on the test ride found it to work very well except for a bad weaving. The seller,[who I don't know] who is a motorcycle mechanic, and really impressed me with his knowledge and his passion of motorcycles, said he had recently replaced the steering head bearings and they needed adjustment. After loosening them a little the bike weaved much less but, still, noticably especially at low speeds. The steering felt very light and quick, maybe unnaturally so, however I am not used to this particular model so I'm not sure about that.
I ended up not buying the bike because I wasn't sure of the possible cause. I worry about possible bent forks, but there are probably a lot of other things it could be like worn shocks, etc. The tires were dual purpose in good shape. The front and back wheels appeared to line up and he said he had checked them with some sort of laser tester. BTW, mileage showing on the bike is 73,000 km's.

Any thoughts. Thanks

[20774]

Yeah, there can be a lot of things to consider in tracking down a weaving situation. I would tend to first suspect the steering stem bearings as they were just replaced. My tests for the correct tigthness is to see how fast the handlebars fall from the center position to one side or the other. If they fall quickly and literally bounce off the stops, that's too tight. If you nudge the bars one direction and they just stay where you pushed them, they're too tight. You want something in between.

The mechanic was right, they usually need adjustment as they bed in. So after some miles, it's reasonable to expect to go back and recheck the tightness.

[ebeeby]

I had a similar experience and a little loosening fixed it.

[Rapid_Roy]

Yeah, there can be a lot of things to consider in tracking down a weaving situation. I would tend to first suspect the steering stem bearings as they were just replaced. My tests for the correct tigthness is to see how fast the handlebars fall from the center position to one side or the other. If they fall quickly and literally bounce off the stops, that's too loose. If you nudge the bars one direction and they just stay where you pushed them, they're too tight. You want something in between.

The mechanic was right, they usually need adjustment as they bed in. So after some miles, it's reasonable to expect to go back and recheck the tightness.
Corrected slightly.

[20774]

Corrected slightly.

Just a bit...+1...isn't there an editor on this site that catches those things! :D