Howdy guys!!

After a 1500km road trip i noticed i can now feel a wobble in the front end and just trying to narrow down some potential causes. i mostly notice it when cornering and in less than ideal conditions: bumpy roads etc...  Also when standing the bike back up after hard lean the front tends to wobble....

2006, 34000kms with good tyres.   I had recently adjusted the chain, maybe not too well. Wheels incorrectly aligned? stem bearings?

I've recently ordered some .85 sonic springs and chain and spokets so i'll be giving her a good going over then. Just want to know what to look out for.

Thanks as always

Clancy

My guess would be the stem bearings needing tightened. I believe my bike needs the same.

Cheers tt.
Is that easy to check/fix?

Put it on the centre stand, prop it so front wheel is off the ground. Sit in front of the bike, grab the lower end of the fork sliders and try and move them front to back. Any play is either in the headstem bearings or the forks, you'll have to figure out which. If the bearings need adjusting I'm sure there's instructions somewhere on here. Its important that there's no noticeable play, but also that they're not tight enough to cause friction, as that will cause wandering.

Just checked Mole.
No free play or looseness from what i could feel.
Cheers for the quick reply!

Maybe you lost a balance weight off the front wheel?

hmmm.
just had a new sports demon front fitted a week ago and i was chatting to the mech while he had the wheel on the static balancer. all seemed well. wobble started before the new tar. Maybe (but i cant recall) after i tightened the chain??? rear wheel allignment do this?
Cheers again mate!  Champion.
 

Be worth checking the alignment just to rule it out. If the chain is a bit worn it may have a tight spot, and if you've adjusted it on the tight side it may give those symptoms. Rotate the wheel a few times to note where the chain is tightest, then adjust it for 35mm play with some weight on the bike. Best is to have someone sit on it while you adjust. If you set it when the suspension is fully extended, it will be too tight when normally loaded. A too tight chain is worse than a loose one, it will cause vibration and overload your swingarm pivot, rear wheel and gearbox bearings.

sweet mate.

the chain does have a tight spot, more like a tight side really.
Found the tight spot on the center stand and adjusted it for free play on the side stand.
Tried to find a happy medium between the (vague at best) adjustment markers on the swing arm and the amount of exposed thread on the threaded rod (?) coming from end of the swing arm. Tightened on the chain side then adjusted on the exhaust side the same number of turns. The exhaust side adjuster seemed looser than the chain side? dunno. Axle nut tightened then adjuster nuts tightened. check for 35mm play. Wonder why the exhaust side was looser when adjusted the same amount of turns as the chain side?

Quote from: Clancy on March 07, 2011, 01:11:58 AM
sweet mate.

the chain does have a tight spot, more like a tight side really.
Found the tight spot on the center stand and adjusted it for free play on the side stand.
Tried to find a happy medium between the (vague at best) adjustment markers on the swing arm and the amount of exposed thread on the threaded rod (?) coming from end of the swing arm. Tightened on the chain side then adjusted on the exhaust side the same number of turns. The exhaust side adjuster seemed looser than the chain side? dunno. Axle nut tightened then adjuster nuts tightened. check for 35mm play. Wonder why the exhaust side was looser when adjusted the same amount of turns as the chain side?

Because the chain puts more tension on the adjuster on that side.
I don't trust the adustment marks, especially the first time. I either eyeball it very carefully (takes a bit of practice), or use a string line on each side, there are threads on this. Once you've established its straight you can do subsequent adjustments by counting the number of flats on each nut as you tighten them.

cheers again mate!
String line it is.

When tightening the chain, always tighten the left side first.

Also, thighten the adjuster nuts first, then the axle.  The adjuster nuts can't do their job if they can't move the axle.

I'm surprised no one suggested to check tire pressure.

+1 on tire pressure check.  I've only had steering wobble problems on one bike, a 85 Nighthawk 650 and the wobble was when going straight ahead and at moderate speeds like 40-50 mph.  Caused by a badly cupped front tire and notchy steering head bearings.  A new front tire corrected it temporarily but it came back, finally eliminated with new steering head bearings.  To check brgs put bike on centerstand, push down back with one hand lifting front wheel, and move steering back and forth at center point feeling for possible notchiness in brgs.

There were some reports over at the EX500 forum of front end wobble at high speeds by several members after putting on a new Demon front tire but your wobble started before the new Demon?  Haven't heard of it more recently.

I've been adjusting my drive chain using the marks on the swing arm for 12 years and 160k miles on 2 GS500 bikes without problems, also did same on previous Honda bikes.  On the GS's those plates with the alignment notch are really too loose and will turn throwing many off on their adjustments.  I start with a too loose chain and first snug down the axle nut a bit so things won't slip while adjusting and most importantly make sure the notch plates are set right while snuging the axle nut by revolving the right side one clockwise and the left side one CCW which is the way it would  turn when making the final tightening of the axle nut.  Adjustments are made by pulling back with adjusters equal amounts on both sides after axle nut is snug.

Final check of alignment, take a ride straight down the road.  If the bars are turned a bit one way or the other when going straight then the rear wheel will be turned the same way and need adjustment correction.

Just cause your tire is newish doesn't mean it's ok. Might have a slight bulge in it somewhere - BUT - as you said it was happening Before hand...

Center stand. Weight on the back. Spin front just to see if you can visually detect a wobble.

Double check your fork brace.

Make sure you don't have a small twist in the forks. (a small difference - even a couple of mm - can cause handling/cornering issues)

Do you have an aftermarket screen on the bike?

Michael

Would a windscreen cause handling issues?

Quote from: Pelikan on March 08, 2011, 12:45:18 PM
Would a windscreen cause handling issues?

On my Honda 919 the small windscreen is attached to the headlight bolts. So any wind on they screen transfers to the handlebars - nake bike, turn bars and headlight turns. So wind could push on the screen one way and end up causing a small harmonic which could create a wobble.

Frame mounted screens are different.

Michael

There is a second step to that head bearing check.  If there is no free play found, then while front tire is still off ground, very slowly turn steering stop to stop a few times while feeling for any roughness or pitting.

When adjusting your chain, a little to tight is worse than a little too loose becasue when the suspension is compressed, the chain gets tighter.  Like bumping along a rough road or while in a curve at speed,

prs

I always have the wobbles when my rear tyre pressure is low or it's worn to death... did you check the pressures and what did it read? I also have luggages which catch wind and that starts a wobble sometimes. The GS can be wobbly over say 140kph on rougher roads, especially in the corners.

Cheers for all the help guys.
Tyres are good.
Do have a screen but has never been a worry before.
Going to do a string line allignment when i put the sonic springs in.
Thanks for all the advice guys. Will report back soon. i have no flat areas at my house so i'm waiting till my mate who is a bit of a boffin has some time and space.

I was short on cash one day and needed a new front and a local dealer mounted up an elcheapo tire for me. I couldn't get rid of the wobbles. About a month later I took it back in and he took the front wheel and tire and checked the runout and something else and found that the tire was bigger on one side than the other. They put a good bridgestone on it(wasn't new but damn close) balanced it up and checked it again. Put it back on and it was perfect. They did the work and changed the tire out and didn't charge me. Needless to say I frequent the shop now. They definitely earned my business.

Long of the short...
Even a new(good) tire can cause issues. When they're junk they suck.