Ducati.ms - The Ultimate Ducati Forum banner

Gran turismo speed wobble

11K views 53 replies 22 participants last post by  DaveK 
#1 ·
Hello all,

after a long think/test/rethink/retest period i decided to buy the 2013 gran turismo version.
Am extremely happy with it, but yesterday i almost had a heart attack.
I decided to take it for a high speed test on the highway, and found the multi got into a speed wobble starting from 180km/h, to a point at 200km/h it was almost out of control. I slowed down and all was fine again.
At that time i was riding in touring mode, with the windscreen in the highest position and only the top case fitted.
Anyone else here experienced something like this?

Greetings from Belgium

Luc
 
#41 ·
I have no clue about this front fork preload and sag stuff. Should I be concerned about this my Sachs equipped 2013? Fastest I've had it up to is 138mph/222kph (indicated) and I didn't feel any wobble. That was on a track of course.
 
#42 ·
I had the wobble on my 2013 DSS bike.

If you are not experiencing it, your preload may be fine or you do not have a top case/bags fitted which increase the chance.

To be sure, you could see what your front pre-load is currently set to, the sweet spot so you don't get wobble seems to start at around 7 turns out and IME gets better with less turns out but you may find the steering requires some more effort.
 
#45 ·
There is something 'wrong' when so many riders with a lot of experience are suffering this "wobble".
My dealer tells me...having checked the 'usual'...the rear wheel balance is the place to go look. Having balanced mine...the wobble went. If i stick 10g of weight back on...it returns with a vengence.
Just a thought for those of you struggling with this.
 
#46 ·
@Aschemkes: It's not being tight on the bars, if that were the case I'd have had tank slappers from this (or been thrown off).

I am experienced enough to know to just rest the hands lightly on the bars and when you get a wobble make double sure your are not gripping tightly and the wobble is still there.

You could put the cruise on and take your hands off completely at the wobble point and it would still be there.

Have you tried a 13 with FPL set to all the way out and a top box fitted at 180kph (max permitted per stickers)? If not, calling BS is a bit strong I think.

It's evidently not a DESIGN fault when increasing FPL fixes it (or as Nick says, changing the wheel balance can fix/induce it), but it is a factory setting fault IMO on (apparently) many bikes.
 
#48 ·
Absolutely, you can also complain to them if the paint on the adjuster gets scratched (it seems to even using a plastic bag to cover it, the same crappy paint as is on the frame where one's boot polishes it off no doubt ....)
 
#50 ·
Lone Ranger.
I think NOT 'playing' is potentially more dangerous than playing!
Dealers should set up the preload for you...but from what I am reading...most don't...and mine certainly didn't...and it was set at manufacture to almost 'max'. I backed it off about three or four turns (can't recall now...did it in the first week of ownership...like we all do!!)to get it in the ball-park, and despite all efforts, I scratched the blue paint.
With reagrd to the damping....well it is there for you to play with it. I ended up with the front comp set about half way between touring and sport for my normal riding...and left the rebound where it was...after playing a bit...and finding not a lot of difference.
The sag the dealer should do...but provided you have a spanner that fits...its easy to do. The damping I really dont think a dealer can do. It's given to up to play with...easily...and will vary from person to person due weight and weight distribution plus a LOT of personal feel...only you can acheive what you want. IMHO.
 
#51 ·
I know this thread is 6 years old, but I'm posting my speed wobble experience in case it helps. I’ve had a 2018 MS950 for about a year now, outfitted with spoked wheels, Pirelli Scorpion Rally’s (the nobbier ones)) and all the Enduro protections because I’m legitimately off-road in the mountains on my farm a few days a week on it, but I”m also out on the freeways of central California weekly as well - so no stranger to “high” speeds on open empty highways. That bike devours it all with ease. Up until last week, I did not own side panniers or a top case. So last week I had to travel several hundred miles and figured I’d do it on the bike, so I bought the matching Ducati MS panniers and top case kit. First, I luuuuuuuuv my MS - if I lost it today there isn’t another bike I would purchase instead - but both those panniers and top case have to be one of the worst value-for-the-dollar purchases I’ve ever made in my life. No sweat, they look pretty and function to hold stuff. But it’s what they did to my ride that is the worst. At 80mph, every time I accelerated to pass trucks or cars - and let’s face it, everybody is driving 80mph on the freeways in California and so practically speaking to pass pretty much anybody on the freeway you need to accelerate from 80mph to achieve passing speed - the front end would go into speed wobble. Every time. I tried changing the spring damping a bit, noticed a slight but not really acceptable benefit. Laying forward on the tank helped often, but I seriously cannot even count the number of times I needed to recapture stability from a speed wobble at high speed on that long road trip. I tried slowing down and just letting other people pass me - but that was almost just as un-nerving on a 7-hour road trip. I may want to use that top case again (despite it being a grossly overpriced P.O.S.), so I guess I’ll go get the Ohlins steering damper installed. If I had two suggestions they would be (a) if you’re going to get a top case, just make sure you buy a steering damper too, and (b) responsible manufacturers may want to recommend the two always be purchased together.
 
#53 ·
I too had a bit of a speed wobble a couple of times WITHOUT the panniers between 200-230. I hanged out the tires to Road 5’s and not more wobble. With the side panniers loaded and (2) 35L bags loaded no wobble at 200+. So I would suspect it to be suspension and or the tires. As for the panniers being POS? Everyone has there own opinion and I too think that they are overpriced. But I happen to think that they are awesome. They don’t hamper the performance like the aluminum ones (not as noticeable) They can hold quite a bit, especially if you have the liners. Don’t leak as of yet (17k on her) and that includes a lot of riding in the rain. Not to mention they are super easy to take on/off with no ugly brackets.
 
#52 ·
How much weight are you loading into the cases, top case specifically? They are not rated for a ton of weight, IIRC only about 15lbs (owners manual has this info). All of your heavy stuff should go in the side cases, as they are closer to the center of mass of the motorcycle and generate less disruption. From a vehicle dynamics perspective, the top case location is the single worst position you could add weight to a motorcycle. Combine that with a relatively light bike, compared to other tourers, and we've got a recipe for high speed wobble. My solution has always been to slow down. The cases also have a speed limit on them, for this reason.

I don't know what impact your 19" front wheel would have on this issue, it seems reasonable to think it might make things worse.

You might want to seek out someone with serious expertise in motorcycle steering and suspension issues and ask them if a damper will help in this use case. I'm not that expert, but I wonder if the type of instability being introduced by this aerodynamic drag is the same as what dampers can remediate. The last thing you want it to install something that might mask the problem until you're going 100+, where it overcomes the damper and becomes a serious problem.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top