Clunk from front end under braking - CBF600

Rob1970 · Nova Slayer Joined: 13 Dec 2012 Karma :

06 plate CBF 600 with 20k

Had it for three months and started noticing a clunk when I come to a standstill with the front brake. i.e traffic lights etc

Tried it on the drive and it happens when I depress the forks and jam the front brake on. Then it won't happen till i move the wheel a bit then do it again

headbearings feel smooth enough so i'm thinking something wrong with the fork or the callipers?

Any ideas?

Aff · World Chat Champion Joined: 05 May 2011 Karma :

Could be your brake pads flopping around, get someone else to operate the brake and push the forks and hold your hand against the calipers/pads to feel for movement.

How much life do the pads have left?

Also how did you check the headrace bearings?
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Rob1970 · Nova Slayer Joined: 13 Dec 2012 Karma :

Just put it on centre stand and checked for notchyness and tried to rock it on its bering with the brake full on and couldn't see/feel any movemnet
but then if you let off the brake and try aagain you get a clunk

Doesn't feel like headset race - I've raced pretty hefty downhill mountain bikes and the feel of the headset wearing out is very different

serlant · Brolly Dolly Joined: 06 Jul 2009 Karma :

it doesn't need to be worn, It could just be slightly too loose headrace bearings. try tightening it up a touch.
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Aff · World Chat Champion Joined: 05 May 2011 Karma :

Check the pads first though, it's easier. Laughing

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martyn107 · Scooby Slapper Joined: 15 Apr 2013 Karma :

Mine is the same year and did exactly the same until I serviced the breaks

oldbiker · Nitrous Nuisance Joined: 15 Nov 2009 Karma :

could be the brakes are fine but the stearing races are loose
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supZ · World Chat Champion Joined: 03 Feb 2009 Karma :

mentalboy · World Chat Champion Joined: 05 May 2012 Karma :

Where can you hear the clunking coming from? Suss that out first before delving into the head races. If you can't hear it you should be able to feel it - another pair of hands will be useful
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Rob1970 · Nova Slayer Joined: 13 Dec 2012 Karma :

Had a quick look last night

There seems to be some movement in the calipers - there is a pivot point on the top where the brake is joined to the mounting plate and a pin at the bottom with a rubber washer on it - this is where a few mm of movement occurs. Not sure whether this is normal or if it isn causing noise. It feels more like a headset issue and I think i can feel the top race moving forward a few mills when I jam on the brake

I don't have anything big enough to tighten it though!

Do headsets come loose often?

supZ · World Chat Champion Joined: 03 Feb 2009 Karma :

as they wear they loosen, you can tighten them up to a point then its time to replace.

had them done last year on the blade.. every now and again during braking it would kinda clunk and feel like the front end moved forwards a tiny bit. got them changed and now tight as a tight thing that's been tightened tightly
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