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Discussion Starter · #1 ·
Today while on the freeway and riding with one hand I noticed a slight headshake. This was at about 50 mph but was still apparent at close to 80. I checked my tire pressure just last night and had both front and rear set to 36 psi as the swingarm sticker says. The tank slapper motion was about an 8th of an inch and constant. I haven't noticed this before....

Is this normal? Is my front tire not properly balanced, or could something else be loose??

Thanks for a reply

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Jason / Arcanum
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Jason,

Always start with the cheap stuff first. :)

#1 Check to make sure the weights on the tire have not come off and unbalanced the front rim.

#2 Check the wear on the front tire.


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Robert Basil
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Discussion Starter · #3 ·
Yes, I did check that as soon as I got home. The balancing weight is on the rim as the bike came. I have about 1475 miles on it and the front tire is in excellent shape. I was just out looking it over, you know, expecting it to correct itself or have the problem jump up and shout. While on the kick stand if I grab the fork tube in about the middle and rock it back a bit I THINK I am feeling a little play along with a slight tink sound.

At this point I'm thinking that the head tube bearings have come loose. I was reading about that being a soon after delivery problem on 98 and 99 bikes.

Does that sound like the problem????

Thanks again

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Jason / Arcanum
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That might do it. I think if the steering head was loose, you would feel a little "thunk" when you go on the brakes. Does that happen?

In any case, it's easy to check. Use a jack or something to get the front end off the ground, and grab the bottoms of the forks and pull on them a little bit. Like pull them towards you, not pull them down. If they move, then the head is loose.

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I agree with R6 racer, I have had that happen
to me many times. I was getting slop in my
R1 and I found out that the shop had set
the front fork settings unevenly. The
preload was mis-matched from one fork to
the other and the dampening rates were
different on each fork. I set them to
factory specs and it all went away... I know
that when I let my hands off the handle bars
at about 50 mph, I get shakes (premature tank
slapper) though this is because my front tire
is about dead...

Good luck, let us know what you find out.


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Since you own a R1 you probably have quite a few miles riding on just one wheel. If you're doing a lot of wheelies then you might have prematurely worn out the steering head bearings. Just my .02

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Discussion Starter · #7 ·
I took it in to the dealer and surprisingly they fixed it while I was waiting at no cost. The steering head bearings had become loose, however it was not due to wheelies. I have managed to keep the front wheel on the ground for the 1800+ miles I've put on it so far.

Thanks for the replies!

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Jason / Arcanum
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[This message has been edited by Arcanum (edited May 23, 2000).]
 

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How have you managed to keep the front wheel on the gorund ????. Mine is airborne a lot and I weight 220 lbs !! :). By the way, i have had to retighten my head bearings twice also. Seems to be a common complaint on the R1s.( Mines a 99 model ). I was beginning to get vicious tankslappers for no apparent reason. When I checked the locknut on the bearing, it was finger tight !. Scary !!

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Yeah that's common on both the R1 and the R6.

Endos and Wheelies will expidite this
losening process as in my expiriences anyway.

Chris



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I had my first experience with the tankslappers this week. I had put 700 miles on the new R6, without any problems. During our daily ride out in the twisties, I accelerated out of a corner, to find myself preparing to wreck. The headshake was so viscious, it almost ripped my hands off the bars. I figured it went side to side 5-6 times. Apperantly this is not just a problem with the R1. I don't feel that the front end is loose, but these bikes really should come equiped with steering dampeners. Is the concensus, that this comes from doing wheelies? Or is it just a problem that can't be helped? Well, anyhow I'm pretty sure mine was caused by the rough road, combined with hard accelleration.

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Today while on the freeway and riding with one hand I noticed a slight headshake.

A guy goes into the Doctor's office, and he says to the Doctor, "Doc, it hurts when I move my arm like this..."

The Doctor says to him, "Okay, don't move your arm like this!"

:D :D :D :D :D :D :D :D :D

But seriously, folks! The reason headshake is becoming more common is because of the way performance bikes are designed these days:

-Ultra-short wheelbases
-Light weight
-High horsepower
-Very steep head angles
-Low-drag steering-head bearings
-Sticky tires

All of these things contribute to head-shake problems. Steering dampeners will help, but the real key is to just be ultra-smooth when you are riding aggressively!

Our streetbikes are at a level that the GP bikes were at just 10 or 15 years ago, so we are experiencing the same kinds of problems guys like Lawson and Spencer had to deal with back then. Fortunately, we have nice, smooth power delivery that those guys could only dream about, but the chassis of our bikes can get a lot closer to the razor's edge before they give any indication of letting go.

So practice being really smooth with your riding, especially when exiting corners on the power. Any extra pulling on your handlebars will contribute to tank-slappers, so try to stay as neutral as you can with the bars, and use your knees and feet to support your weight...

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Well said, Scott :)

A steering damper will help too, but probably 99% of all headshake problems can be solved with good riding technique and a well set-up motorcycle. Those handlebars are only there to turn the bike, they're not meant to hold onto!

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My 2000 R-1 has a little head shake to with no hands on the bars. I think it does this because the wheels are only staticly balanced
down the centre of the wheel. I think if you were to balance this dynamically at the bead seats like the Kaw ZX9 it might settle it down. There is no question that a steering damper would also cure it. Head shake in cornering is caused by tire deflection and tire loading and unloading over bumps. They say the cure is to roll on the throttle. Has anyone tried different balancing or tried different dampers. Thanks Hal

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