Knocking from front forks

[T0MMY]

I've recently noticed a clunk coming from the front forks of my CB-1 as they move in and out. Doesn't appear to be headset bearings or wheel bearings or anything but something internal in the forks.

Any ideas? It seems to be worse on the very cold mornings and improves as the bike is ridden and the forks are moving for a bit although it's always present.

[Kickstart]

Hi

Bushes? Wheel bearings (although unlikely). Fork brace / mudguard loose? Even brake pads moving in the caliper.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Suntan Sid]

[neatbik]

Could well be bushes, but as said already check out the brake calipers and pads, and wheel/headbearings first.

[chris-red]

I had the same sort of thing I tightened the headstock 1/8th of a turn and it went away

It only happened under braking
____________________
Well, you know what they say. If you want to save the world, you have to push a few old ladies down the stairs.
Skudd:- Perhaps she just thinks you are a window licker and is being nice just in case she becomes another Jill Dando.
WANTED:- Fujinon (Fuji) M42 (Screw on) lenses, let me know if you have anything.

[T0MMY]

This happens all the time whilst I'm going along, just a continual knocking but not rhythmic. If I bounce the forks at a standstill you can hear and feel the knocking and it definitely sounds like it's inside the fork legs. Pretty sure it's not brake or wheel related and the headset bearings feel fine too.

[chris-red]

Only one way to find out, strip them down, I imagine it would only be on one fork so try to find out which one, although it is probably worth stripping both and changing seals bushes oil etc. as forks are rarely serviced.
____________________
Well, you know what they say. If you want to save the world, you have to push a few old ladies down the stairs.
Skudd:- Perhaps she just thinks you are a window licker and is being nice just in case she becomes another Jill Dando.
WANTED:- Fujinon (Fuji) M42 (Screw on) lenses, let me know if you have anything.

[T0MMY]

I need to use the bike everyday and don't have a lot of spare time so it's a bit awkward. Probably have to wait 'til the xmas holidays if I want to take it off the road.

[T0MMY]

Ok, had a bit of time today at work to look at the bike. Seems I was wrong about it being internal to the forks; it only makes the noise when the front brake is on and I bounce the forks. If I bounce them with it off then they're fine which makes me think headset bearings or front brake. The caliper bolts are tight and the disc has no play in it. The caliper does move a bit when you wobble it by hand but then I seem to recall that's normal (amazing that I'm not sure after 14 years of motorbikes ) as the slider pins have a bit of play in them?

As for the headset bearings I can't feel any play in them with the front wheel off the floor and I can't produce the clunk by pushing and pulling on the forks.

Any of this shed any more light on the problem?

[chris-red]

AFAIK the disc should have play on it (floating discs) and the callipers shouldn't.


I'd tighten the headstock bearing mine was tight and I had to put alot of force through it to tighten it and it only moved a fraction, but that cured the problem. It is easy and quick to do.
____________________
Well, you know what they say. If you want to save the world, you have to push a few old ladies down the stairs.
Skudd:- Perhaps she just thinks you are a window licker and is being nice just in case she becomes another Jill Dando.
WANTED:- Fujinon (Fuji) M42 (Screw on) lenses, let me know if you have anything.

[T0MMY]

[T0MMY]

Ok, did some more playing over my lunch break...

With the back brake on there is no clonk whether or not the front brake is on so it's the forwards and backwards motion that causes it, not the telescoping up and down of the forks.

On that basis, this could still be front brake, headset or something inside the forks really couldn't it

[chris-red]

Tighten the headstock.
____________________
Well, you know what they say. If you want to save the world, you have to push a few old ladies down the stairs.
Skudd:- Perhaps she just thinks you are a window licker and is being nice just in case she becomes another Jill Dando.
WANTED:- Fujinon (Fuji) M42 (Screw on) lenses, let me know if you have anything.

[T0MMY]

I'm inclined to agree with you

[neil.]

+1 Had similar symptoms and it was the steering head bearings that needed tightening up.