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Shaking Front Fork!
#1
Hi. i have a problem with my front fork. When i drive from 140 km/h and beyond, the front fork begins to shake (forward and backward) like the wheel is out of balance.
With 190 km/t it is pretty bad. Could it be the wheel? It is worse under acceleration. From 0-130 there is no problem.
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#2
Have you ever changed the fork oil?
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#3
Can you tell us all a bit more? Is it Is it vibration/twisting or more of a shimmy? Is there any noise associated with it? Turning, does it get better or worse? Could be wheel bearings, steering head bearings or something as simple as an out of balance wheel, any leakage at the top of the fork oil seals?
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#4
Springs and fork oil is changed. Oil seals ok.
About 140 km/h the front fork viberates / shakes +-2 cm forward and backward, total ca. 4 cm. My Gps on the handbar almost shakes off.
No probs with turning, small turns and high speed turning is perfect.
Bearing ok when i check it with the bike on the center stand.

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#5
(01-08-15, 07:26 PM)Bimbam link Wrote: Bearing ok when i check it with the bike on the center stand.

Hi Bimbam, which bearing, are you talking about the front wheel?
Treat everything in life the way a dog would- if you can't eat it or foc it, forget it.
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#6
Yes, front wheel and back is ok as well.

Dont try to be the best in town, just be the best, until the best come arround
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#7
Next I'd take a look at the steering head bearings. Put the bike on centre stand and check for play both forward to back and left to right. Get someone to put their weight on the rear, to raise the front wheel. With a single finger on the handlebar check the free movement, feeling for any stiff spots or notchiness. Balance the bar central and let it fall, don't matter if to the left or right but they should fall all the way on their own.


Treat everything in life the way a dog would- if you can't eat it or foc it, forget it.
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#8
Whatever it is I would seriously stop doing those speeds again until it's sorted out!
More people are born because of alcohol than will ever die from it.
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#9
Head bearings checked, no probs. Nice free movement on the handlebar and no stiff spots.The bar falls nicely both ways.
So i guess it must be the wheel thats out of balance.



Dont try to be the best in town, just be the best, until the best come arround
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#10
What condition is the front tyre in? Starting to square off? Cheap brand?
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#11
You're saying 2cm, that is A LOT of play?
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#12
Tyre is Metzler Roadtec Z8 110/70 ZR17 and it is to be changed soon.
I have done 15.000 km on the tyre and mabye the shaking is getting worse.
I got the bike last sommer and i dont drive above 130 km/h, but sometimes it is fun to have a full acceleration and some speed.
Darrsi; When it shakes so much at high speed, it dosent feel safe  Sad


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Dont try to be the best in town, just be the best, until the best come arround
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#13
Who actually changed your fork oil?


There are 2 levels listed in the manual, the 98/99 bikes need more oil than the 00/03 ones as they don't have preload adjusters on them.
Is it possible that you don't have enough oil in the forks?


I've not really ever had a wheel so out of balance that it violently shook, but i s'pose that it's very possible. Just make sure they balance it when you change the tyre. 


If you ever consider checking your oil out, or next time you replace the oil, use 15w instead of 10w, it firms up the front end very well.
More people are born because of alcohol than will ever die from it.
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#14
That's a very good call from Darrsi, definitely check the fork oil levels.
I've assumed that it's more likely to be the steering head bearings, as the free play is forward & backwards not up and down. Anyway, other than replacing the fork oil, front tyre, and wheel/headrace bearings, It's well worth your time re-torqueing everything at the front end, those vibrations won't have done you any favours!
Treat everything in life the way a dog would- if you can't eat it or foc it, forget it.
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#15
Oil changed and correct level checked.
The shaking was there, before and after.
I used 20W and it helped a bit.
Everything is re-torqued exept the headrace bearings.
I think, i will start with a new tyre.


Dont try to be the best in town, just be the best, until the best come arround
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#16
(02-08-15, 08:02 PM)Bimbam link Wrote: Oil changed and correct level checked.
The shaking was there, before and after.
I used 20W and it helped a bit.
Everything is re-torqued exept the headrace bearings.
I think, i will start with a new tyre.
Good call - come back and let us know if the issue's still there

Good luck
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#17
Any update fella? Still shaking?
Those are my principles...if you don't like them I have others.
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#18
Hi. I am getting a new tyre next week.
I'll be back  8)
Dont try to be the best in town, just be the best, until the best come arround
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#19
New tyre fixed the problem!.
I got new Metzler SportsTec M7RR, front and rear.
Dont try to be the best in town, just be the best, until the best come arround
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#20
(19-08-15, 04:43 AM)Bimbam link Wrote: New tyre fixed the problem!.
I got new Metzler SportsTec M7RR, front and rear.


As tyres wear from new they will become slightly unbalanced over time, even more so if they're not wearing evenly for whatever reason.
Having a tyre/wheel balanced again half way through the tyres life would make perfect sense to compensate for the general wear and tear, but nobody ever really does this.
At least it's sorted now, and you got new tyres out of it too.
More people are born because of alcohol than will ever die from it.
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