Forking Forks !

[Looney tune]

On my last couple of outing (while back now ) I heard a noise coming from the front end, like a gentle knock, every now and then on bumpy surfaces. Last night I went for a spin and the noise is there every time I run on / over a rough surface. When I hold the front brake on and push on the bars to compress the suspension it does it every time on the way down. When a friend does it and I hold the fork legs I can feel it as well as hear it. I have checked brakes, mud guard and anything else that might be loose on or to do with the forks / head stock. Bike is a 2008 FZ1n with 10600 miles.
Has anybody had this before or can point me in the right direction for a fix ?


Many thanks, Russ

[jackojet]

Hi Russ
Is it the brake pads rocking in the calipers against the pins?
My gsxr was a twat for it.
Try giving your brakes a spray with brake cleaner

[Looney tune]

Hi Pete, thanks for the reply.


When I checked the pads they had a little movement yes, but when I jammed them 'solid' with a screw driver and bounced the front end the noise was still there..
The mystery continues, what about fork oil ? Worth a change ?

[stevierst]

My fz1s does that too! Not particularily worried, but it would be nice to find out what it is.

[AyJay]

FZ1s have compression in one leg and damping in the other, I believe. Is it coming from one side?

[Exupnut]

We thought u were gonna come back

[unfazed]

4 items could cause what you describe
Brake Pad Pins - You seem to have ruled this out
Worn Fork bushes  - mileage probably to low for this
Wheel bearings. - Remove calipers and lift the front . Grab wheel top and bottom Try and rock it left and right
Head Race Bearings - If they are not notchy then it might be worth while retorquing them.
Cover the tank to prevent damage.
Remove the handlebars (makes the job easier)
Loosen the top fork pinch bolts
Remove the steering stem nut and washer (This is tight 113Nm)
Lift off the top yolk
Remove the lock washer
Remove the first ring nut
Remove the rubber washer
Loosen the second ring nut
At this point decide if you want to go further and regrease both top and bottom bearings
If you decide not to, then
Tighten 2nd ring nut to 52Nm - Requires special tool to do it properly. I made one out of an old rear shock adjusting tool.
Loosen it again (not to much) and retighten to 18Nm (do not tighten more than 18Nm)
Refit the rubber washer
Refit the top nut and tighten to a good finger tight and refit the lock washer.
Refit the rest in revere order of removal.
The steering stem nut is 113Nm
Upper Fork leg pinch bolts are 26Nm
Hopefully that will solve it.

[Looney tune]

FZ1s have compression in one leg and damping in the other, I believe. Is it coming from one side?

Sorry, been busy.


It's on both sides thanks.

4 items could cause what you describe
Brake Pad Pins - You seem to have ruled this out
Worn Fork bushes  - mileage probably to low for this
Wheel bearings. - Remove calipers and lift the front . Grab wheel top and bottom Try and rock it left and right
Head Race Bearings - If they are not notchy then it might be worth while retorquing them.
Cover the tank to prevent damage.
Remove the handlebars (makes the job easier)
Loosen the top fork pinch bolts
Remove the steering stem nut and washer (This is tight 113Nm)
Lift off the top yolk
Remove the lock washer
Remove the first ring nut
Remove the rubber washer
Loosen the second ring nut
At this point decide if you want to go further and regrease both top and bottom bearings
If you decide not to, then
Tighten 2nd ring nut to 52Nm - Requires special tool to do it properly. I made one out of an old rear shock adjusting tool.
Loosen it again (not to much) and retighten to 18Nm (do not tighten more than 18Nm)
Refit the rubber washer
Refit the top nut and tighten to a good finger tight and refit the lock washer.
Refit the rest in revere order of removal.
The steering stem nut is 113Nm
Upper Fork leg pinch bolts are 26Nm
Hopefully that will solve it.

As above, sorry for late reply.
Wheel bearings were fine when doing initial checks so I will check the head race bearings and many thanks for the info on how to do this, great stuff. I will report back when I have carried out the work required, could be a while as it's silly season at work tho  :'(


Thanks again.