front end unstable while cornering

[kcowgergmm]

My bike is getting a weired slight shake well it just feels unstable when high speed cornering. What do you think the cause is i believe tire preasure is good

[jonboy99]

How long have you had the bike? Has it always done it or recently started?
Culprits are dodgy suspension setup, knackered/tight/loose head bearings, sezing suspensions linkages, or most likely you not relaxing properly on the bars if you're new to the bike.

[kcowgergmm]

I have had the bike for a little over a year and but 7500+ miles on it it has been in the last few days i have noticed it doesn't feel right and my thought were something wrong with the tire, wheel bearing or, head bearing. It feel like a steering damper would cover up the problem but i want it to be right

[johnnyrod]

Rebound damping is too soft on these bikes. Stick some thicker oil in (15W or 20W if you're a lardarse). Check your sag setting too (preload).

[SVeeedy Gonzales]

Using the front brake in the corner? Lots of people do without noticing and it can make corners tough as the suspension geometry changes through the bend

What are the tyre pressures? Some people find that going higher or lower than the manufacturers spec helps. Ideally it's 33 front 36 back but some use 36 front 42 back. Too high can make the bike feel like it has reduced grip, too low can make it feel sluggish.

How old are your tyres? By 7500 miles the front will be knackered if it's the original tyre, and the OE tyres that come with the biuke are rubbish anyway

Any obvious wear or flat spots on the tyres? If the tyre (front or rear) has a flat spot that can make leaning the bike over scary as it goes from the flat to a point before getting onto the curve of the tyre, so leaning over and back up are awful, though it's OK when at full lean.

Other stuff - something could be loose, you could be wearing thick gloves which mucks up the handling/feel of any bike... but those ones above are the main problems.

[Scoobs]

Rebound damping is too soft on these bikes. Stick some thicker oil in (15W or 20W if you're a lardarse). Check your sag setting too (preload).

That could be it. I have just backed off the rebound damping on my CBR back to factory settings and I am getting an unstable feel at speed. I'll whack on a turn of rebound damping again to see if that helps.

[Viney]

My bike is getting a weired slight shake well it just feels unstable when high speed cornering. What do you think the cause is i believe tire preasure is good
It could be any of the above, also when you say high speed, whats high?

So in order
Head barings (Check of tightness or if they are worn)
Tires - As said at 7500+ they will be past thier best
Wheel straightness
Suspension - Oil and springs will help

Somone will be a long soon to say that you need to swap the whole fornt end over for a Gixxer front end etc etc. Ive done 50k on my bike, and im still to think that it needs doing.

[kwak zzr]

when you say high speed cornering how fast we talking? my 650 used to act all weird front and back on 100+ big sweeping bends, i just put that down to budget shocks.

[Viney]

when you say high speed cornering how fast we talking? my 650 used to act all weird front and back on 100+ big sweeping bends, i just put that down to to much polish on the bike.:D

[kwak zzr]

:flower:

[kcowgergmm]

Using the front brake in the corner? Lots of people do without noticing and it can make corners tough as the suspension geometry changes through the bend

What are the tyre pressures? Some people find that going higher or lower than the manufacturers spec helps. Ideally it's 33 front 36 back but some use 36 front 42 back. Too high can make the bike feel like it has reduced grip, too low can make it feel sluggish.

How old are your tyres? By 7500 miles the front will be knackered if it's the original tyre, and the OE tyres that come with the biuke are rubbish anyway

Any obvious wear or flat spots on the tyres? If the tyre (front or rear) has a flat spot that can make leaning the bike over scary as it goes from the flat to a point before getting onto the curve of the tyre, so leaning over and back up are awful, though it's OK when at full lean.

Other stuff - something could be loose, you could be wearing thick gloves which mucks up the handling/feel of any bike... but those ones above are the main problems.

I have pilot powers on them that have done aproxmately 6000 miles of not to abuse riding mostly flat land so the centers are more worn than the sides
I am running 36-42 psi in my tires and i know for a fact i am not on the front brake i killed that bad habit a while back but that can scare you to death if you hit the brakes very hard while leaned over. I really dont think there is any flat spots on the tire and i have ridden with really thick winter gloves so i know that isnt it either

Rebound damping is too soft on these bikes. Stick some thicker oil in (15W or 20W if you're a lardarse). Check your sag setting too (preload).

That is in the plans soon but i really don't think that is what is causing this issue i got the preload on the front full and the back shock at 4 click stock for the S. I am planning on emulators or a gixxer fork swap and i only weight 150 so i am not exactly a lardarse i am built light for speed

It could be any of the above, also when you say high speed, whats high?

So in order
Head barings (Check of tightness or if they are worn)
Tires - As said at 7500+ they will be past thier best
Wheel straightness
Suspension - Oil and springs will help

Somone will be a long soon to say that you need to swap the whole fornt end over for a Gixxer front end etc etc. Ive done 50k on my bike, and im still to think that it needs doing.

how do you go about checking the head bearing

when you say high speed cornering how fast we talking? my 650 used to act all weird front and back on 100+ big sweeping bends, i just put that down to budget shocks.

over 90 it becomes apparent but if you are going in a straight lines and wiggle the clipons it seams to shake more than it did before correcting itself out.

[Viney]

how do you go about checking the head bearingYou need to get the front wheel off the ground but with the ability of being able to turn the forks from lock to lock. A sutible strong friend can help here! Get them to pull the bike up on its side stand (one hand under the tank to lift, and the other on the rear seat to balance. Then you get hold of the forks and trun them from lock to lock. If you feel any notchyness or grinding feeling then your bearings are shot. Also wiggle them from back to front to see if there is any play. If you have one of those Abba type stands (The type that pivots on the swing arm pivot) then it will be even easier

[jonboy99]

I have pilot powers on them that have done aproxmately 6000 miles of not to abuse riding mostly flat land so the centers are more worn than the sides



If your rear tyre is 6000 miles old, then I wouldn't bother with a single other adjustment until I'd got new rubber on - this is a classic symptom of squared off tyres, even if you have spent most of your riding almost upright. Might as well replace the front too, they're only be 1-2k left in it, and toghether they'll transform the bike.

Lastly, have you tried easing the preload off? Fully wound on at your weight might well be stopping it absorbing the bumps properly,while cranked over and the steering has to wobble to try and compensate. Worth a try i'd say, especially if you've recently made it harder.

[kcowgergmm]

If your rear tyre is 6000 miles old, then I wouldn't bother with a single other adjustment until I'd got new rubber on - this is a classic symptom of squared off tyres, even if you have spent most of your riding almost upright. Might as well replace the front too, they're only be 1-2k left in it, and toghether they'll transform the bike.

Lastly, have you tried easing the preload off? Fully wound on at your weight might well be stopping it absorbing the bumps properly,while cranked over and the steering has to wobble to try and compensate. Worth a try i'd say, especially if you've recently made it harder.

I haven't adjust the preload since last year it has been like that for a long time . I know that i should get new tires soon but i dont have any money so i will need to get all the life i can get out of them

[johnnyrod]

Set the front preload so you have about 25mm sag when you sit on the bike (i.e. forks are comressed by 25mm from fully extended). If it's too high it won't help. You might have set them like this because of fork dive, but it won't help if you screw the handling up in other ways. Too little rebound damping at the front gives a vague feel, particularly when you're on the gas coming out of a bend.

Might not be this at all, just fleching out my comments!

[kcowgergmm]

worth a try ill see if that changes anything