Modern Vespa

If you're really fighting an uncontrolable wobble, or shimmy, I have developed, and can supply, a hydraulic steering damper assembly for modern Vespas that is normally used with a sidecar installation.
I unconditionally guarantee that it will cure that problem.

I can be reached by phone at (916) 635-5566, or at blueldr17@gmail.com

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Pics? Detailed info

That's something worth looking into.

I'd like to jump in this discusion with a few questions. I have severe wobble when I just take my hand of the bars to flip my face shield up or down, at just about any speed. I have Michelin Pilot pure tires. !0k miles on bike and front tire and my second rear tire. The tires show no signs of cupping or irregular wear. but I will be replacing them with Pirelli Diablos soon. I have BiTubo shocks from and rear. I've reset the steering head brgs once with the wheel hanging but I've never trusted that they were right. Lots of times when changing load either by starting out or braking at very low speeds I hear a clunk in the front which, given how light the steering is, I've suspected was loose steering head brgs. I know the problem got a lot worse when I installed the factory top box. But running w/o it is not an option since my wife uses it for a back rest and we ride two up a lot. So my questions are; might the clunking be improperly adjusted brgs? which direction should I go in experimenting with shock preload to solve this? Could it be the tires even though there is no evidence of irregular wear? The tires are inflated to factory specs and I have the heavy bar ends on. TIA

if I had a GTS I would be investigating a aftermarket steering head bearing solution. Also I would be looking at the wheel bearings as well and the spacing of the wheel.

there is a solution for this, it just has to be found.

Indeed, no issue with my 2015 GTS either. I certainly experienced the classic deceleration wobble with my 2008 GTS. Seems to me, all this validates Jess' earlier comments that the problem was primarily associated with the front suspension and steering geometry of the GTS. In my experience, the redesign of the front suspension appears to have resolved the problem.

Never had the problem with my 2007. Been running the Heidenau tires, 140 on the back and do have the Vespa top case.

All two wheelers with a front suspension will exhibit this behavior.

It will occur at different speeds (usually on deceleration), and to different degrees.

Good tires, properly inflated and keeping loose upper body will minimize the effects.

The wobble on the GTS is not severe, no "tank-slappers" to worry about so you aren't going to crash UNLESS YOU PANIC and try to fight it.

On any PTW, if you do start an oscillation, the best action to take is to go with it, loosen your upper body and gradually accelerate or decelerate slightly to get out of the range.

I experienced some wobble with the original Savas, but never thought of it as being anything serious or important at all. Changing tires the Heidenaus effectively eliminated any noticeable trace.

P.

^^^^ this! Never had any wobble on my 2014 GTS (old model). I can ride at 80 MPH, get both hands off and slow down completely without the slightest wobble. Had new tires recently and although I feared a wobble might wake up, it runs as smooth as before. The curious thing is that the club members I asked never experienced any GTS wobble. There's been a lot of debating on this, but IMHO, if this is design related then it should occur always and persistent. I suppose the problem, if any, can get induced/worsened by tires, balancing, steering tolerance, extra weight on the back etc etc.

I do have a big wobble when I drank too much Limoncello, but that problem is mostly induced by my Italian friends. Sleep and asperine 100 usually solves the problem

Hail, long live reviving ancient posts

Well said......

I could get my BMW's & other bikes to wobble, but never my Moto Guzzis.