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front end knock


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Hi, when I hit a sharp edge or abrupt bump, I hear a dull knock sound from the front end.  The bump could be the far side of a manhole cover, or when  entering a parking lot and you hit the flattened curb at the edge of the road at a good speed.  At first I thought it was normal since this bike is brand new.  Just curious if others experience this. Spring preload and compression damping is set on the softer side. 

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There's some play in the windshield adjuster mechanism that's kinda noisy with strong bumps.

As a rule of thumb, a piece of advice with these bikes: They're noisy in general, and it's best to not worry about Weird Noises.  There's lots, and they'll drive you batty if you think something's wrong.  

This is kind of an extension of how we can get a whole lot of bike for a very low price.  Money is saves on simpler chassis mounting methods.  You'll notice when you get into taking fairings apart is that they're all either spring or rubber mounted with very simple collar/rubber grommet setups.  This is great for light bumps and vibration, but on harder bumps, stuff moves.  It's fine and harmless, it allows the fairings to flex a fair bit (vs breaking, I suppose, which would obviously not be ideal) but you hear it. 

But these are extremely reliable machines.  So yeah, there's a whole lot of oddball noises (particularly including that front end clunk on hard bumps) that are completely normal.

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I noticed something similar with my 2019 GT.  I could pump the forks up and down and would feel a mild "clunk" upon rebound.  It was still there after setting up the suspension for my weight and riding style but it never bothered me.

I upgraded the suspension with some good aftermarket parts and now that feeling is gone.  Don't really think it was ever a problem though.

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There is nothing like spending a day riding with friends in the grip of a shared obsession.

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Thank you, and yes I agree that the way the fairings etc are mounted leads to some movement or jiggliness.  I've always been OK with some jiggle  🙂. I guess it would even stranger if there was no clunk sound when hitting a bump so I'm going to continue not worrying about it.

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Think this question has come up before and there is something in the suspension that will make a dull knock as @johnmark101 talked about.  I'm feeling lazy or would try to find it.  As I recall it's not a problem just the way it works.

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15 hours ago, johnmark101 said:

I noticed something similar with my 2019 GT.  I could pump the forks up and down and would feel a mild "clunk" upon rebound.  It was still there after setting up the suspension for my weight and riding style but it never bothered me.

I upgraded the suspension with some good aftermarket parts and now that feeling is gone.  Don't really think it was ever a problem though.

One thing that does is the floating rotors.  They're quite stiff, so they don't freely move, but when you're pushing the bike forwards and back with the front brake on you'll definitely hear them clunk.  My MT07 did that too, and I nearly went crazy trying to figure out where it was coming from, because - for the life of me - I swear it sounded exactly like a shot steering head bearing clunk.  My first time on the Tracer, I rocked it back and forth on the front brake and sure enough... Clunk.  

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I noticed the same thing on my FJ.. also assumed it’s knocking coming from the windshield as I know it does have some free play, at this point I don’t think too much of it.. plus I keep the music playing in my helmet all the time so it’s no longer noticeable.

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  • 5 months later...

I was finding the front end knocking sounds from my 900GT really annoying, the knocking didn't happen that often, but when it did it just made the bike sound really...... cheap. So I decided to strip down some of the front end plastics to find anything that looked like it could do with padding or tightening. One thing I found that has made a huge difference is adding some padding around the headlamp adjuster rods where they go through the little metal clamps near the knobs. The clamps are very loose and metal to metal contact, so the knock when going over bumps can be quite loud. I wrapped a couple of turns of self-amalgamating rubber tape over the rods where they go through the clamp but there sould be lots of other fixes possible, although need to make sure that the rod can still be turned.

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I personally checked the steering head bearings 10 times in the first two weeks that I owned the bike because it was driving me nuts. I once had a bad experience on a bike with bad head bearings and am seriously paranoid since. I've come to the conclusion its the forks/springs character and just drive it.

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5 hours ago, NormR said:

I personally checked the steering head bearings 10 times in the first two weeks that I owned the bike because it was driving me nuts. I once had a bad experience on a bike with bad head bearings and am seriously paranoid since. I've come to the conclusion its the forks/springs character and just drive it.

Yep.  I'd love it if someone actually found where the clunk comes from - I know for me I really don't think it's the headlamp adjuster rods (they're way too light to make the heavier clunk) but who knows.  I fretted about it for quite a long time before just giving up and accepting it as normal. 

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For my bike, 2019 GT, it was loose bushings in the slider tubes. Also known as "metal sliders" 4FM-23171-40-00. I put the front wheel up off the ground and could pull and push the front wheel back and forth and see play/movement at the fork seal. I called Yamaha USA and they claim that is "normal". Their normal is to allow a certain amount of play (loose tolerance) to keep cost down. The problem I have with that philosophy is that that can induce oscillations and many unknowns into the handling of the bike.

I ended up having the front end rebuilt by Traxxion Dynamics and that fixed some of that "clunk"

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  • 7 months later...

I recently had the steering head races replaced as the ravages of potholed British roads caused the front end knock to worsen. The mechanic said the OE ones were only just up to the job and, clearly, someone at Yamaha saved $0.05 per unit by specifying them; another case of compromising safety to reduce cost. The replacements were quality after market items with much longer rollers and I have to say that it is a worthwhile change. There is now zero knock of any kind and I now have huge confidence in the front end. It was around £300/US$366/CAD477 including parts and labour. 

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8 minutes ago, Paddy01 said:

I recently had the steering head races replaced as the ravages of potholed British roads caused the front end knock to worsen. The mechanic said the OE ones were only just up to the job and, clearly, someone at Yamaha saved $0.05 per unit by specifying them; another case of compromising safety to reduce cost.

I dunno... what is on the odometer? Much depends on your maintenance regiment, and sometimes the luck of the draw... if the assembly wasn't just right from the factory. I am at 70K km on original bearings and have zero issues. Costs me a bit of labour and some grease each year to keep bearings in good shape. Just how much worse would your roads be than our winter battered kind?

Mind you... when time comes, I will be swapping OE hardware for a tapered set.

canada.gif.22c5f8bdb95643b878d06c336f5fe29f.gif - IBA #66956 - 2015 Yamaha FJ-09

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Storage of the bike outside in weather will also introduce a lot of moisture leading to premature failure, especially if regular maintenance isn’t performed. 

tapered roller bearing replacements are the way to go for sure.

-Skip

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