[ntula]

high speed wobble..

when i go above 80, i feel a bit of wobble on the bike at the front now. the tires have only 1k miles on them..
actually i am not sure i would describe it necessilly as wobble, but it feels a bit like mild vibrations and not the most stable feeling, like the front end is superlight/lifting a little and traction is minimal. i did not notice this before i moved the clipons i have in a half inch.... so did i upset the balance and front suspension when doing so... i feel almost like i need to sit on the tank to make it more stable.

 

[Speeddog]

Which year and model of Monster do you have?
How many miles on it?
Any mods that you might think are effecting it?

 

[chi998]

did you move the forks?

 

[ntula]

M900S, 1999, 17k miles on it. recently serviced.

no i did not move the forks... i have rizoma m201 clip-ons... i had them fully extended but brought them in a little.
i noticed it after moving the clip-ons in a little.. i have to lean on the tank to make the bike feel stable at speeds above 80... i would expect that at maybe 100+, but not at 80.... .. i wonder if i need to raise the rear a little.. (adjust the rear shock load..).. any good places to go to get the suspension set up correctly for my weight and mods, if you think that would help.. below 80 the bike handles great..

it feels like it is just too sensitive.... i also do not have bar end weights on it at the moment...

i only rarely ride above 90 on it, just not in that much of a hurry anymore, but when i do need to or out in the desert, i don't wnat the bike to feel like it is going to start tank slapping.

 

[Speeddog]

As far as good places to go to get your suspension set up, whereabouts do you live?

 

[ntula]

san francisco.

i thought about getting a dampener for it, but is seems like i should get it set up first.

 

[lung]

speed balance? wheels have weights? Recent tire change?

 

[Speeddog]

san francisco.

i thought about getting a dampener for it, but is seems like i should get it set up first.

You can ask the folks over in the Bay Area, the Ducati MOB: http://www.ducatimonster.org/smf/index.php?board=13.0
There's quite a few good shops there.

Definitely worth getting your suspension set up, it might be OK, but when it's for sure right, you'll be a much happier rider and it will eliminate it as one of the likely causes of your issues.

 

[MotoCreations]

Obvious question -- but have you tried moving the clipons back into their original position and seeing if the problem disappears? Even a little change creates a differing torque factor to turn the bars due to muscles used and slightly different wrist angles.

 

[Archimedes]

.. .. i wonder if i need to raise the rear a little.. (adjust the rear shock load..).. any good places to go to get the suspension set up correctly for my weight and mods,

Well if the front end is unstable, raising the rear ride 'height' will not make it any better (assuming your bike has ride height adjustment in the back). It will only make the bike steer quicker and be more sensitive to inputs on the bars. If your rear pre load is so off that the rear end is squatting, you could need to add some pre-load to the shock. Have you set your sag properly? If not, get a buddy and do that first.

Re suspension set up, there are shops all over that could help. I would think Munroe in the city would assist.

All that said, my new S2R doesn't feel all that stable anywhere compared to my last bike. Very soft, flexible and lively. Definitely not a rock when its going down the road. Just gonna have to adjust to it.

 

[ntula]

oic, i would be putting more weight on the front if i raised the back and compressing the front.. i need to have someone set it up ..

hmmm.. it does not dive, the front feels okay... it may just need the combo of adjustment and the dampener.

my other bike is stable to about 135 without a dampener.. but it is longer and the rake is not as lean... guess

i am expecting it to be like that...

yes i did have new tires put on.. and come to think of it, they put on silver weights on my black rims.. and black weights on my friends white rims so i asked them to make mine black.. they put the black ones next to the place where the silver ones were, but not at the same place.... 'haps i had a little balancing issue combined with incorrect suspension adjustments.

 

[Archimedes]

oic, i would be putting more weight on the front if i raised the back and compressing the front.. i need to have someone set it up ..

hmmm.. it does not dive, the front feels okay... it may just need the combo of adjustment and the dampener.

my other bike is stable to about 135 without a dampener.. but it is longer and the rake is not as lean... guess

i am expecting it to be like that...

yes i did have new tires put on.. and come to think of it, they put on silver weights on my black rims.. and black weights on my friends white rims so i asked them to make mine black.. they put the black ones next to the place where the silver ones were, but not at the same place.... 'haps i had a little balancing issue combined with incorrect suspension adjustments.

Couple things. First, adjusting your preload is not really adjusting your 'ride height'. If you increase preload, thereby decreasing the sag you will raise the seat a bit, but it's not the same impact as a rear ride height adjustment. You definitely want to get your sag set right. It does make a big difference in the feel of the bike. If you can't get it right after adjusting preload, it means your springs are not right for your weight and you need to re-spring.

Second, a damper will have no impact on a high speed wobble (unless you've got it set up really, really tight, which you shouldn't for street riding or slow turns will be a chore).

Third, those wheel balance weights are balancing the rim and the tire, so when you put new tires on, they will likely move due to differences between the old and new tire. If they put new weights on and they knew what they were doing, I would assume the tires are in balance.

My advice would be to get your sag set up right and then see how it works. If you still have a problem, go to a local suspension shop and ask for their help in sorting it out. I've worked with a couple here in the valley over the years and they've been pretty helpful.

 

[test-reg]

Do remember to check everything for play, head bearings, swing arm, shock pivots, wheel bearings. You did check tire pressure, didn't you?

 

[kbuddy]

+1 to the above checks. There's a nice list of things to check in Snyder's manual and I'm sure I saw it before in another thread although I think Howie listed most if not all of them. I had a slight wobble/vibration at 80-85mph that worsened as speed increased that was caused by my rear wheel being misaligned. I straightened it using a flat edge on the rear sprocket and it went away.

 

[hiero]

+1 on bearing checks

 

[ducpainter]

When my 96 had worn bearings it would "wobble" in corners. It was actually the rollers falling back into the little divots that wear in the race, correct, fall, correct.........................=wobble.

 

[Transplant]

How soon after you put on the new tires did you notice the 'wobble'? Did you go over 80 mph soon after or just recently?

If your balancing weight is mounted slightly off or the guy replaced with incorrect weight, would be enough to cause it at higher speeds...

...would have tires rebalanced and aligned, first.

I would think rotating clipons in would increase stability - shorter lever arm, so less effect of rider inputs to steering?

 

[punker248]

I'm also thinking out of balance, the change in bar geometry could eggagerate this, but wouldn't likely cause it.

Get the balance on your front wheel checked. While you're at it get the rear done too.

Justin