@wspollack you may be correct. However, comparing two of the same generation bikes with the same issue does not indicate the bikes are performing as designed or intended. TO the contrary it could indicate a manufacturing run on steering head bearings that were out of spec, undetected, and installed. My 23 has none of this wobble that you are both experiencing, which is what I think most would accept as the bike performing as designed or intended. Tire pressure may have something to do with it, but 4 PSI is unlikely.
@Fedeskiff Bill and I are both guessing as we are not able to observe your bike. You're the one who is going to get hurt if there is a catastrophic failure. I would test for play, and retorque everything on the front suspension. It could also be an item with a runout parameter like your rotors or rim. I am not a worry wart by any means. But there is no way that I would leave that undiagnosed.
Bill, I am not being contrary or argumentative by any means. I might be in agreement with you if it were ~1 degree of wobble; but
@Fedeskiff video is showing at least 5 degrees of play if my observations are correct. That is neither safe nor normal.
No offense taken, no contrariness assumed, etc.
1) As I say, in a couple of months, when the salt clears and my riding season starts again, I will perform this experiment ... with my hands nearby, at the ready, prepared to take over in a split second.
I am assuming that my two different-model-year, delivered about a year and a half apart, C 400 GTs were manufactured at vastly different times. My money is also on the newer bike's behaving like the older bike.
2) Have you tried that experiment yourself? Not trying to be a smartass or snarky here, just really wondering.
Just slowly coast down from, oh, about 40+mph, with your hands off the grips, but, obviously, very close, ready to pounce.
3) As I say, this happened to me, early on in my '22 C 400 GT ownership. I was just stretching or something, at about that coasting-down speed, and, whoa!, the bars started flip-flopping just like in the video that
@Fedeskiff posted.
I was a little startled, of course -- who wouldn't be -- but I was not really surprised. I have read about this same no-hands-wobble issue, over the decades and regarding vastly different bikes -- standards, huge baggers, etc. -- on assorted bike forums, as well as experiencing this myself (usually at around 30mph or so) on them. Eventually this very issue becomes a topic on all the bike forums I've been on (not as prevalent as which is the best oil, of course).
So all I said to myself, a few seconds later, was: "Okay, so that's the harmonic no-hands wobble speed of this scoot -- don't do that again." And I haven't (but, as I said, I still take my hands off, but at higher speeds, when I've been sitting in the saddle for a couple of hours, and the road is straight, and there's no traffic around, and I can see that there are no deer around, etc. etc., and my shoulder blades are starting to tighten up a bit).
You can get a taste of this prevalence pretty easily: google something such as
motorcycle handlebar wobble hands off while riding, and stand back. I just did that (1.8m hits), and did some random skimming. Here are a couple of snippets.
From a Yamaha Tenere forum:
The wobble while decelerating with NO HANDS is very common on most motorcycles but most folks never notice it because they keep their hands on the handlebars, tightening the bearings will take away the wobble but tightening them to much will cause wondering issues that you definitely won’t like so be very careful .
From a Vespa forum:
"Doctor, Doctor, it hurts when I do this.
Don't do that."
Nothing to worry about unless you have wobbles with your hands on the bars.
Most motorbikes (scoots and cycles) exhibit a bit of deceleration wobble, usually through 30mph. It's not important.
If you notice funny steering characteristics when holding the bars, notchiness, vibration, that's another story.
BMWs do it, Yamahas do it, let's do it too.
Of course, as you indicate, there are also loads of suggestions that the steering-head bearings are shot or misadjusted. Or the tires, or frame, or something else, are out of balance.
And I imagine that there are many bikes that are misadjusted in some way or other. But, as I say, I keep coming across this no matter what bike I have, on that bike's respective forum(s), and when dealing with low-mileage variants of whatever make and model. So, as I say, I wasn't surprised at all. A tiny bit startled maybe, but not surprised.
drive.google.com
