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HELP. Major head shake.

Started by JDS 07 S4Rs, August 28, 2008, 09:49:01 PM

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JDS 07 S4Rs

Quote from: gm2 on August 29, 2008, 11:20:25 PM
:-X


LOL. I know what your going to say.


never heard of a forward riding position inducing headshake.


That's true DP. I do recall having to sit a little more forward on my older bikes in order to stop the high speed wooble.

I do know that when it happened, I was more foward, & to be honest. I had just come down from a nice little 2nd gear power wheelie. slammed it in 3rd & it made 2 little wiggles, then shocked so hard that I thought it was going to tuck the front wheel at 140 ish(kph)

Now, what I did also discover was - tires were over inflated. 33 on front, 34 on rear. (not sure why they put so much PSI in to begin with ? )
So, I am thinking that between to much preload in my rear shock,(I will admit. I never checked the sag when I was done. & I did put 7 full rotations on that baby) & to much tire pressure caused this headshake.

On a little different note. Tracknight was a blast. I knocked off 0.6 sec off my previous personal best in the 1st session. 2nd & 3rd session's we got in behind a bunch of slower riders. After that my timer was working. This 636 rocks, best $2300 bucks I spent  :)
2007 S4RS
2007 1098S Salvage Title (that's it. NO MORE BIKES)
02 GSXR 750 Trackbike - Ins Write/off
06 ZX636R Trackbike  - Ins Write-off (I couldnt help it, the price was right)
2003 BMW 1150R
2004 450 YZ
&,,, a few others :-)

darylbowden

Quote from: JDS 07 S4Rs on August 30, 2008, 08:44:27 AM

I will admit. I never checked the sag when I was done. & I did put 7 full rotations on that baby

Holy Shit!   :o :o  Dude, you should've told us this earlier.  This is what caused your problems.  Do me a favor and promise me you're going to stop make the beast with two backsing with your suspension by yourself because obviously you don't know what you're doing.  Preload is measured in 1/4 turns, not large prime numbers.  You completely changed your effective sag by doing this.

And btw, I think gm2 was referring to the GP shift comment.  GP shifting has NOTHING to do with headshake and will do nothing to solve it.

gm2

Quote from: darylbowden on August 30, 2008, 08:53:27 AM
And btw, I think gm2 was referring to the GP shift comment.  GP shifting has NOTHING to do with headshake and will do nothing to solve it.

nah, i was referring to this entire thread.  i can't even believe it.

but yeah, shift pattern has no relevance..
Like this is the racing, no?

JDS 07 S4Rs

Quote from: darylbowden on August 30, 2008, 08:53:27 AM
Holy Shit!   :o :o  Dude, you should've told us this earlier.  This is what caused your problems.  Do me a favor and promise me you're going to stop make the beast with two backsing with your suspension by yourself because obviously you don't know what you're doing.  Preload is measured in 1/4 turns, not large prime numbers.  You completely changed your effective sag by doing this.
And btw, I think gm2 was referring to the GP shift comment.  GP shifting has NOTHING to do with headshake and will do nothing to solve it.


It was only 1/2 a inch or so. It was a experiment, that went bad. They shouldnt put so many threads on them things  :)
2007 S4RS
2007 1098S Salvage Title (that's it. NO MORE BIKES)
02 GSXR 750 Trackbike - Ins Write/off
06 ZX636R Trackbike  - Ins Write-off (I couldnt help it, the price was right)
2003 BMW 1150R
2004 450 YZ
&,,, a few others :-)

gm2

#19
Quote from: JDS 07 S4Rs on August 30, 2008, 12:17:44 PM

It was only 1/2 a inch or so. It was a experiment, that went bad. They shouldnt put so many threads on them things  :)

dude.  seriously.  you're going to hurt yourself.  STOP fu@king around with your suspension.

you may understand what each adjuster does, i get that.  and i get the desire to DIY, and that you have an affinity for trying to learn this stuff.  but, with all due respect, what you DON'T get is they all work together, in a very specific harmony, under varying very specific conditions.  it's literally a science.  and little tiny adjustments (to say nothing of SEVEN MOTHEREFFING TURNS) can have serious downstream effects.

one more thing about this science: the faster the bike goes, the more differently the suspension settings react.  so you may have a decent idea what you're doing @ <100mph, but those settings could be disaster at greater than that.

please stop.  your mechanic's ego is going to end your riding all together.
Like this is the racing, no?

JDS 07 S4Rs

2007 S4RS
2007 1098S Salvage Title (that's it. NO MORE BIKES)
02 GSXR 750 Trackbike - Ins Write/off
06 ZX636R Trackbike  - Ins Write-off (I couldnt help it, the price was right)
2003 BMW 1150R
2004 450 YZ
&,,, a few others :-)

CIE

Dude... get someone at the track to set up your suspension for you.  They were charging $30 to do it this weekend.  Pay the $30-50 and enjoy the ride.  Listen to the suspension experts.  They know what they're doing and they're much cheaper than replacing broken bike/body parts when you crash because you had the urge to start making adjustments on your own.

Generally speaking most sport bikes are sprung and damped in such a way that they can be tuned to work for most riders.  You can make major changes (springs, oil, etc), but chances are good that a few twists and turns and you'll be dialed with all your stock components still in place.
"Too young to know better, too old to care....."