F800GS unstable at higher speeds

Baiazid · 12-17-2012, 06:45 PM

Hi,

recently I had 30.000km service and I asked them to replace tires as well.
Service consisted also in changing fork oil.
I have now Haidenau K60.

I went for a trip next day after the service and noticed on highway when I go beyond 110kmph, bike starts to be very unstable. Front fork starts to shake semi-violent (left and right). If I slow to 105 .. all is fine.

Before this I used to go 160kmph with no drama.

What can be?

Reaver · 12-17-2012, 06:53 PM

Did they balance the tires? If the aignment was off it would track funny but since it's speed related I'd say an out of balance front wheel. Bent rim?

Baiazid · 12-17-2012, 07:18 PM

Quote:

Originally Posted by Reaver

Did they balance the tires? If the aignment was off it would track funny but since it's speed related I'd say an out of balance front wheel. Bent rim?

Saturday I am going again into the service.

Rim has a small bend (had that for last 2 years) and never affected my stability at any speed.

Tires look balanced (they have extra weight added on one side) but I cannot tell if was done properly.

sorebutt · 12-17-2012, 08:05 PM

If it is a tire balance issue it should be an up down type vibration. I'm gguessing front wheel alignment. Loosen the pinch bolts that hold the axle on one side. Then bounce the front end up and down a number of times. Then tighten the pinch bolts and take it for a spin.

Gangplank · 12-17-2012, 10:32 PM

Could be a bad tire. Ive had a few sets of TKC 80's that got the death wobble over 80 mph.

Did they mount it right?

catweasel67 · 12-17-2012, 10:34 PM

sounds lke a wheel balance issue to me - maybe a weight fell off?

Angryrican · 12-18-2012, 03:42 AM

It's most likely the tire, there are a few threads about K60's doing this when brand new and it goes away after a few hundred miles of break in

Loutre · 12-18-2012, 04:38 AM

Quote:

Originally Posted by Angryrican

It's most likely the tire, there are a few threads about K60's doing this when brand new and it goes away after a few hundred miles of break in

<-- What he sais. It'll go away after a couple hundred miles. Gives you another reason to get the bike out there and ride it... It's for safety reasons of course

JRWooden · 12-18-2012, 05:25 AM

Quote:

Originally Posted by Angryrican

It's most likely the tire, there are a few threads about K60's doing this when brand new and it goes away after a few hundred miles of break in

A:
Do you know how that works?
What's going on in the first few hundred miles?

ragtoplvr · 12-18-2012, 05:30 AM

check your tire pressure. Now. Unstable on a motorcycle is most commonly a low or over inflated tire. You can pick up a nail in the dealer parking lot. If pressure is right, then you can look for other stuff. If you are recommended to run 42 psi for tire life, try the recommended pressures in your manual.. The longer life might not be worth it.

Rod

Dr E · 12-18-2012, 05:41 AM

Have you checked your preload on your rear suspension? When that gets off, one of the signs will be front end wobble or instability.

Good luck!

runnin4melife · 12-18-2012, 07:59 AM

I don't take my TKCs above 80mph because it feels as if the bike is floating, put a set of road tires and I can go well over 120 with no problem. Same rims, same suspension just the tires. Some are worse than others, My first set of TKC80s, the front was really bad but I didn't have my new suspension then so I just rode it out and they went away (I pulled and checked balance, and whether the rim was bent or true, all was fine). I have never ran the K60s so don't know about them. I was looking at them for my Alaska trip so I hope they don't have an issue at 80+...

DoWorkSon · 12-18-2012, 10:23 AM

Just got k60's on my F8... They are fine at 80mph+... No issues, feel similar to stock street tires..... They have less than 50 miles on them too. Just a slight vibration at low speeds(15 mph), but not bad

Angryrican · 12-18-2012, 01:27 PM

Quote:

Originally Posted by JRWooden

A:
Do you know how that works?
What's going on in the first few hundred miles?

I don't, I'm going by the scientific evaluations of the members of this forum

joking aside it's mention quite a few times in this forum in different tire threads, I personally have never had the issue but I'm am super anal about tire pressure setting on and off road and dialing in suspension

JRWooden · 12-18-2012, 06:40 PM

Quote:

Originally Posted by itsatdm

I have posted this before without any feed back. A 15 min free mod, what do you have to lose?

Feedback: It worked for me, thanks Gary!

12-17-2012, 06:45 PM	#1
Baiazid ^OP Adventurer Joined: Jul 2009 Location: Sydney Oddometer: 74	F800GS unstable at higher speeds Hi, recently I had 30.000km service and I asked them to replace tires as well. Service consisted also in changing fork oil. I have now Haidenau K60. I went for a trip next day after the service and noticed on highway when I go beyond 110kmph, bike starts to be very unstable. Front fork starts to shake semi-violent (left and right). If I slow to 105 .. all is fine. Before this I used to go 160kmph with no drama. What can be? __________________ Blog Chernobyl: http://www.travbuddy.com/travel-blogs/50834 Video Chernobyl: http://www.youtube.com/watch?v=uFmPY8gog5Q

12-17-2012, 06:53 PM	#2
Reaver Amusing Myself Again Joined: Aug 2008 Location: In Transition, Ontario Oddometer: 584	Did they balance the tires? If the aignment was off it would track funny but since it's speed related I'd say an out of balance front wheel. Bent rim? __________________ Life is a rollercoaster........and I'm not strapped in!

12-17-2012, 10:32 PM	#5
Gangplank Advenchaintourer Joined: Jul 2003 Location: Reno/Tahoe NV 89509 Oddometer: 1,993	Could be a bad tire. Ive had a few sets of TKC 80's that got the death wobble over 80 mph. Did they mount it right? __________________ Shiver'd Fork Conversion Elka Suspension Group Buy Precision Trackdays Reno NV

12-17-2012, 10:34 PM	#6
catweasel67 BAN - Born Again Noob Joined: Aug 2009 Location: Vienna, Austria Oddometer: 5,517	sounds lke a wheel balance issue to me - maybe a weight fell off? __________________ Planning NA 2010 NA 2010 Adriatic Loop August 09 Mandello Guzzi Protest Sept 09 "I've got the key to the gates of paradise...but I've got too many legs!!" Jeff "Civilized men are more discourteous than savages because they know they can be impolite without having their skulls split, as a general thing." -- Robert E. Howard

12-18-2012, 05:41 AM	#11
Dr E Chasing after theory Joined: Mar 2010 Location: Pacific Northwest Oddometer: 142	Have you checked your preload on your rear suspension? When that gets off, one of the signs will be front end wobble or instability. Good luck! __________________ Life is the last thing you experience before you die...living is what you do every day to get you to that point...

12-17-2012, 08:05 PM	#4
sorebutt Beastly Adventurer Joined: Jun 2008 Location: Lewiston,ID Oddometer: 1,082	If it is a tire balance issue it should be an up down type vibration. I'm gguessing front wheel alignment. Loosen the pinch bolts that hold the axle on one side. Then bounce the front end up and down a number of times. Then tighten the pinch bolts and take it for a spin.

12-18-2012, 03:42 AM	#7
Angryrican know nothing all Joined: Mar 2011 Location: North NJ Oddometer: 212	It's most likely the tire, there are a few threads about K60's doing this when brand new and it goes away after a few hundred miles of break in

12-18-2012, 05:30 AM	#10
ragtoplvr Beastly Adventurer Joined: Oct 2007 Location: S. W. Mssouri Oddometer: 4,551	check your tire pressure. Now. Unstable on a motorcycle is most commonly a low or over inflated tire. You can pick up a nail in the dealer parking lot. If pressure is right, then you can look for other stuff. If you are recommended to run 42 psi for tire life, try the recommended pressures in your manual.. The longer life might not be worth it. Rod

12-18-2012, 07:59 AM	#12
runnin4melife Gnarly Adventurer Joined: Mar 2012 Location: Maryland Oddometer: 488	I don't take my TKCs above 80mph because it feels as if the bike is floating, put a set of road tires and I can go well over 120 with no problem. Same rims, same suspension just the tires. Some are worse than others, My first set of TKC80s, the front was really bad but I didn't have my new suspension then so I just rode it out and they went away (I pulled and checked balance, and whether the rim was bent or true, all was fine). I have never ran the K60s so don't know about them. I was looking at them for my Alaska trip so I hope they don't have an issue at 80+...

12-18-2012, 10:23 AM	#13
DoWorkSon Gnarly Adventurer Joined: Oct 2012 Location: North CA Oddometer: 113	Just got k60's on my F8... They are fine at 80mph+... No issues, feel similar to stock street tires..... They have less than 50 miles on them too. Just a slight vibration at low speeds(15 mph), but not bad

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: .
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode