Got the death wobble on the Fz6

[Plymothian]

Had the same the other day, but I was nailing it up a sliproad, front wheel was very light and went over a bump in the road. I just eased off and the wobble cured itself

 

[The_Paragon]

But unless the nose packed down, that's not likely the cause. Did you give any thought to the possibility of the bars being turned upon touchdown?

Bars were straight. I'm no stranger to front wheel in the air action!

 

[banjoboy]

Yepp, it was dirty my pants kind of moment..

Heres the Scene:
Was accellerating hard from a stop sign. There was a small lump across the road, nothing that would usually cause any issues. As I went over it the front tire lifted a little, again.. nothing that would usually cause any concern. but once the front tire touched back down, she went into a full on death wobble.. I doubt it was close but it almost felt like the front forks were hitting the steering stops from side to side...

I grabbed the bars as tight as I could and rolled on the throttle until it straightened out..
I have no idea if that was the best way to go about it, but it seemed logical at the moment, and I didnt have much time to think about it!

Your Thoughs? Experiences?

Ohh yeah, and this was my second time out on brand new Pilot Road 3's... I cant fully blame the tire, but its not exactly confidence inspiring to have that happen after putting new tires on..

If'n yer bike doesn't wobble in a straight line at speed, the tire's prolly fine. :dunno: (Though I hated PRIIIs 'n luv PRIIs) Could be yer steer'in head bearings iz loose?
Next time ya get a "death wobble" keep on the gas, hang on tight to the barz, butt try too remain loose in yer arms, shoulders, 'n the rest of yer body. :thumbup: Just relax 'n let the bike do it's thang.

Glad you're OK!
As I've found several things can place the ball in motion as often times its all about circumstances.

I would be curious to know the ride height or SAG front and rear. If you the rider have compressed the rear a substantial amount (such that the nose is up), this could perpetuate the light nose wobble. Is there any work done to this bike from the OEM setup? Read up on setting sag as some of this could be adjusted out to make it more stable all the time. Hint: this suggests it may be on the edge of unstable. Be careful.

Had a very similar thing going up a steep incline as the nose went up and came down. It felt pretty twitchy...

Hummmm, interesting concept cuz I have mah rear preload cranked all the up, 'n mah forks slid 'bout 9 mm in the triple clamp, (Lowering the front) 'n I get head shake all the time. (I likez mah bikes twitchy like mah wimmenz. )
It don't bother me nun, cuz it keeps thangs interesting! :cheer:

 

[motojoe122]

In reply to Moto Joe: I have those adjusters, nice to hear they worked well. Did I miss how much you weigh? And your riding style preference is what?

I'm about 200-210 with gear and across the board with riding style.

 

[The_Paragon]

I changed back to some Honda Pro (showa) 5wt. oil. According to the charts its about the same viscosity as stock yamaha 01 oil. The bike behaves pretty normally now, and handles the bumpy roads quite a bit better. Less nervousness.
I went back to 5wt oil just to confirm that it was acting screwey because of the excessive dampening.
Changing back makes me realize just how undersprung this front end really is. It probably statically sags 50% of the travel with me sitting on it. Looks like what I really need is some better springs.

MotoJoe: Where did the adjusters come from? Has anyone tried something like this with stock springs to add a little pre-load to the front end?
View attachment 53145[/QUOTE]

 

[lawlberg]

If'n yer bike doesn't wobble in a straight line at speed, the tire's prolly fine. :dunno: (Though I hated PRIIIs 'n luv PRIIs) Could be yer steer'in head bearings iz loose?
Next time ya get a "death wobble" keep on the gas, hang on tight to the barz, butt try too remain loose in yer arms, shoulders, 'n the rest of yer body. :thumbup: Just relax 'n let the bike do it's thang. Hummmm, interesting concept cuz I have mah rear preload cranked all the up, 'n mah forks slid 'bout 9 mm in the triple clamp, (Lowering the front) 'n I get head shake all the time. (I likez mah bikes twitchy like mah wimmenz. )
It don't bother me nun, cuz it keeps thangs interesting! :cheer:

Sounds like my setup - :thumbup:

 

[motojoe122]

I changed back to some Honda Pro (showa) 5wt. oil. According to the charts its about the same viscosity as stock yamaha 01 oil. The bike behaves pretty normally now, and handles the bumpy roads quite a bit better. Less nervousness.
I went back to 5wt oil just to confirm that it was acting screwey because of the excessive dampening.
Changing back makes me realize just how undersprung this front end really is. It probably statically sags 50% of the travel with me sitting on it. Looks like what I really need is some better springs.

MotoJoe: Where did the adjusters come from? Has anyone tried something like this with stock springs to add a little pre-load to the front end?
View attachment 53145

[/QUOTE]
I got them from a company called Sling Shot Racing. Found them on flea bay, but easier to Google it.

 

[Carlos840]

I got them from a company called Sling Shot Racing. Found them on flea bay, but easier to Google it.[/QUOTE]

They look nice, but i really don't like the blue and gold scheme and they don't have any other colors available.

Do you have any pictures?

Also, in real life how often do you use them? Front sag is pretty much set in forget, under which circumstances do you feel the need to play with your preload?

 

[motojoe122]

I got them from a company called Sling Shot Racing. Found them on flea bay, but easier to Google it.

They look nice, but i really don't like the blue and gold scheme and they don't have any other colors available.

Do you have any pictures?

Also, in real life how often do you use them? Front sag is pretty much set in forget, under which circumstances do you feel the need to play with your preload?[/QUOTE]

That was the only pic I had left. I bought the adjusters when I did the spring and oil swap. It made it easier to set the sag instead of having to remove and cut the spacer stock until I found the length I needed.