head shake on 2004 VFR 800

Have not been here in a while. I have a question with head shake on my 2004 VFR 800. I got the tires changed early last year (at about 30 K miles) and had problems with head shake from the time I picked it up. Tires were bought and installed at a large multi franchised dealer that our company does mechanical work for.

Anyhow the old tire on the front needed replace (bridgestone) so I decided to replace both the front and rear tires with Conti Road Attack tires. Sizes are 180/55 ZR 17 and 120?70 ZR17 for the front and rear respectively. They put the bike on a lift and checked the front end for fore and aft play. I also did this with my center stand, and I cannot feel any play at all.


Here is the problem I have. Took it back to the shop and they agree with me on this. It only head shakes when you take both hands off the handlebars. Never with one or two hands on the bars, regardless of cruising, braking, accelerating or going 115 mph. Rock solid as could be. Just head shakes when decelerating , like coming down an off ramp and you want to stretch your arms out. Then it is bad. Very much like a tire out of balance, but as soon as you put ONE hand on the bars, it goes away!! You CANNOT feel anything through the bars when either hand is on the bars when decelerating. Does this at any speed. (ramp at 30 or 130)

They suggest new tires, but I don't know. What does someone think on here?

 

its the tires, my metzler M-1's did the same.
it seemed to be a tad bit better below 40 psi in the front. ( I ran 34-36 psi in the front for the most part )
last year I went w/ the M-3's and the problem went away.
The head shake was never bad enough to worry about and I am used to it any way from the 16" front on my old FZ 700 yami. That bike would go just about lock to lock w/ hands off the bars but was never its gonna make you crash issue.

What do you have the forks set at?

 

My fork setting are still factory. What would you recoded? I usually use this bike only when hauling my now 12 year old I put a Corbin Lady Gunfire seat on it just so I didn't loose him in trying to keep up to mom, who rides a mean CBR 600RR! I bought the bike for my wife a long time ago, but she now graduated 2 years ago to a new 2008 CBR leftover, so this is mine now.

So anyway, change the tires and it will be good. OK. Thanks a lot.

 

You know, it turns out that those engineers at Honda, cuz they're very smart, never thought guys might try riding with no hands.........cuz it makes no sense.

What are you doing with your hands, texting ??

Hands on bars and no problems. Your hands and arms are the only steering damper it needs.

But it might be wise to check steering head bearings, cuz at 30k, they're likely showing some wear.

 

I would not even worry about changing the tires if they are in good shape.
you could try to set the front pre load to 2 lines showing ( don't know what your setting is at now )
the shake is nothing that is going to make you loose control of the bike.

 

check balance too, it might be that they forgot to balance your tires, or that they did balance them, but the weights fell off somewhere along the way
so start with
visual inspection of tires & wheels for
tire pressure
suspension settings
wheel balance - out of round

 

Thanks 02VFR RIDER. At least someone had something positive to say. It didn't do it before the tire change, and yes the wheel was balanced dynamically (a second time after I took it back an hour later). I think it is the tire too, but thought I would come on here and ask. Would you just change the front, or buy a marching rear tire? I am not concerned about money, just want it right. I don't know as much about road bikes, but on MX bikes we usually don't mix brands to much since one brands aspect ratio is different than another in MX.

 

I had the same problem with my 2003. If you took both hands off it was scary!

I readjusted the head bearing load and it fixed it completely.

Give it a try... it's a free fix.

John

 

I would just run it, unless it bothers you that much.
I would change both if you are going to go w/ a differnt brand.
I have run different brands before w/ no problem as long as they are both say " sport " tires or Touring tires.
again my Metzler M-1 front did the same as your conti and I ran it w/ out any issues other then a slight shake w/ hands off the bars.

 

the main problem w/ the new tires is.
everyone has a way to deal w/ issues like turn in, grip.
some use dual compounds, some tire profiles, 0 degree belts and so on.
something to think about before mixing and matching...
I don,t think a combo of any of the above would kill you, but you prob would loose alot of feed back from the mis matched tires.

 

headstock bearings would be my first look... would bet a paycheck

 

VFR Headshake

I posted here a while back about the same issue with my 02. I got a lot of help and also some dumb ass replies. I've tried re balancing, I have matched maxxis tires, resetting the head bearing preload, changing the suspension settings, all to no avail. What really pisses me off though, is these chuckleheads who say to just not take your hands off of the bars. Did you guys ever stop to think that maybe there is some underlying problem here. Suppose I'm decelerating from a high rate of speed and some other factor such as some uneven pavement may cause the headshake to start up. The fact is, it shouldn't do it. Whether my hands are on the bars or not, there is some problem that needs to be corrected. I've come to the decision to sell the bike. I do not feel confident in, or on, this machine.

 

You're right that there is a problem gmarn, but presumably you don't like the bike enough to consider fixing it.

Have you owned it since it was new? Ever been down? Bumped into where maybe something is out of whack (for lack of a better term)? How old are the tires themselves? It IS possible to put new tires on and have a bum tire. It may not necessarily be in the mold or compound itself (i.e. where you wouldn't feel it with your hand), but possibly and internal problem. Radial tires are know for having belts slip within the tire. Even a fraction of inch can make a significant difference in the feedback transmitted to the bars.

Going back to the initial poster's comments, I also had this exact same problem. But even the SLIGHTEST amount of pressure - one finger on the bars - and the vibration would go away. Brought it in to my mechanic, checked everything from top to bottom, no problems. Put another new tire on, and problem was solved. 3000 miles later, and never an issue.

I know there are numerous people on here that know way more than me when it comes to the mechanics of a bike. All I'm saying is that no part on a bike - including tires - is guaranteed to be perfect just because its new. Chock it up to shit happens.