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Knocking sound under braking


catrike16
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Hi All,
I went out for a short run yesterday, as I came to a stop I noticed a loud knock, loud enough to make me stop and look for a second, it came from the front forks area.
I now have a noticible knocking sound when I use the front brake and the forks compress.
I hadn't noticed it before, the bike is still in its run in period. My past few bikes have been BMW so this sound is alien to me, it may not be to others though!
Any thoughts, normal? Anyone else experience this?? Cheers ?
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I hear it too when coming to a standstill at lower speeds e.g. at a red light in town.
 
My theory is that it is the floating disk moving - you have the brakes applied and the suspension dips as you stop. Once fully stopped you still have the brakes on but the suspension recovers to the static position. This changes the load on the floating disk so it moves and you hear it knock as it reaches the end of the movement range.
 
My bike has done it since new and has 16500 miles now so it is not something I worry about.
This signature is left blank as the poster writes enough pretentious bollocks as it is.
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I usually ride with ear plugs, but did a short ride last week without ear plugs. I did not hear any such knocking, maybe you should check rotors for excessive play. I would also check all bolts in the fork and steering head bearings for proper torque.
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You should not be getting any knock sound. And it sounds as if something isn't right. Check it out and resolve before riding again.
 
Check that the caliper bolts, and fork yokes (you colonists call it something else I think... Triple widget or something?).
 
Yes these bikes do have floating discs, but I have never heard them clunk, but imagine they could if they are worn....so even if it is from the disc I would get your dealer to check it out.
Honda SS50, Kawasaki Z200, Honda 400/4, Yamaha TDM900, Yamaha XT660Z Tenere, KTM 990 Adventure, BMW R1200GS, Mr Stevens, and my favourite of all: Yamaha MT-09 Tracer...a bit like FJ-09 only properly named :¬P
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  • 3 weeks later...
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I sometimes here a clunk from the rear brake when I first start to slow. It has done this the whole time I've had the bike. I've inspected and reinspected; everything is tight. I'm sure it's just the brake pads clunking in the caliper.
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Another possibility is that the rear shock is making the noise as it extends under braking. Could be stiction or something. I'm still running the crappy stock shock.
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Mine has been making a noise since new. It makes a small clunk noise if you are stationary and push down on the front end, while holding the front brake. Can't tell if it is the forks or steering, but I've always had it.
 
I'll have someone push for me sometime while I listen for the area it's coming from.
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piotrek, sorry to burst your bubble, but the discs are floating. If you look closely the disc is "attached" to the wheel via 6 (I think) little round button looking devices. The inner portion of the disc support has "half of the moon" that goes around that item, the rotor itself, the other half. That joint allows for expansion and contraction and helps with rotor alignment through the caliper. 5 fasteners bolt the inner mount to the wheel. It can and has become worn on other Yamaha models. Replacement can often get rid of any noise.
 
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