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Discussion Starter #1 (Edited)
Over time (last 400 miles, new bike) I've felt an increasingly more apparent knocking feeling, primarily coming from the footpegs. I initially thought it was the kickstand bouncing around but it doesn't seem to be that because I can hold the stand with my heel and it still does it. It feels a lot like part of the frame is moving (or something else sorta big based on the knocking I'm feeling), but the bolts appear to be on there tight. I checked the four lower ones each side (any idea of ft-lbs torque value there?). Strangely I dont feel it that much when going faster than parking lot speeds, or maybe there is just so much else going on I cant feel it. BTW, I dont have to be going over big bumps to feel this, Its little pavement transition type bumps I'm talking about.

Could it be front suspension related? I did bottom them out pretty hard on a 3" pothole once. My nearest dealer is a few hours away, so it'd be nice to sort this out on my own.

Does anyone have any other things I can check? Anyone had this issue before?!
 

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Hi @Sub,

Check the two bolts (one each side) that hold the rear part of the exhaust silencer to the frame (via a bracket).

I can't say I noticed any knocking myself but within my first 1,000 miles I did notice (by accident) that both of these bolts were missing and the exhaust was just free floating! This would possibly bang/knock against the bracket.

I always assumed mine had just vibrated loose and fell out. No idea how long it had been like that.

Certainly worth a look.

Good luck and let us know how you get on?

Cheerio,

Roy
 

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I have noticed the same thing. Mine has just been serviced at the main dealer who did a thorough nut and bolt check to make sure everything was as it should be. I only feel it at slow speeds - usually when I pull into our drive and usually when the steering is turned sharply to one side. If you look at the footpegs pins they are quite a loose fit and I suspect it's just the pegs transmitting the very stiff suspension setup.

Be interesting to see if other people are noticing the same thing.

Update - I've just been out and given everything a good shake and there's nothing obvious other than the footpegs are quite loose on the pins. I think I shall try some form of rubber washer on the pins to take up the slack and see if that makes any difference - but I'm pretty sure the knocking is just vibration being transmitted through the frame and showing up as movement in the footpeg pins.
 

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I get 'feedback' through the rear brake pedal when coming to a halt. I presume this is ABS kicking in.

It's like a feathering or vibration.
 

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Discussion Starter #9
Chico, I am within the acceptable weight range. :) I can feel there is ample suspension travel left front and rear.

Kilyung, I have felt this knocking since before any mods went on.

Chez, you may want to use a little less rear brake!

Taurus, we have the same issue!! Please let me know if you are able to get it to go away.
 

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You made me curious. My bike makes a dull knocking sound when I roll out of garage onto to the street. I gave the rear caliper a shake and it’s loose on the caliper pins. Normal because the brake is not applied. Might be the source of your ghost.
 

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You made me curious. My bike makes a dull knocking sound when I roll out of garage onto to the street. I gave the rear caliper a shake and it’s loose on the caliper pins. Normal because the brake is not applied. Might be the source of your ghost.
You may have a point there. The rear caliper is quite a loose fit when not under load. At parking lot speeds, as when I'm just rolling it onto my driveway, I tend to just touch the rear brake so I wonder if it's the play in the caliper being transmitted through the frame and being felt via the loose fitting of the footpegs.

When it eventually stops raining here - basically it's rained non-stop for the past few weeks and I live in a rural location where the roads are currently covered in mud - I shall take it out and see if avoiding the rear brake makes the knocking disappear.

Still - a wet day off has meant I've spent the morning in the garage servicing my CBF commuter so it's not all bad news.
 

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if you're off the throttle when it happens, or just feathering it, it could be chain slack slapping around. hit some bumps while you're accelerating and see if it's the same when you go back over those bumps with the clutch in.
 

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It seems there are two threads relating to this. Alhacking started a thread which someone has posted that it’s caused by the frame flexing and the gyroscopic effect of the crank turning atlow rpm is being felt through the pegs.

Not sure if that’s the case but worth checking. It seems to be a common experience.
 

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Not sure. The weather here is still very wet so I'm riding my commuter rather than the Bobber.

I've looked at the foot peg mounting frames and the do flex a bit but whether that's anything to do with it I'm not sure.

I've got some thin rubber washers I'm going to fit on the foot peg spindle to see if taking up the play there makes any difference.

Going off the frequency of the knocking I'm feeling I'm not convinced it is engine related. It seems much more in timing with suspension movement over slightly uneven ground.
 

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Discussion Starter #16
I agree. It feels like the inside of the cat is bouncing around or something. Its a low frequency and heavy mass moving around and causing it, its not piston or chain related etc. This knock is consistent with a major part of the bike moving around. I feel it mostly in the foot pegs, not hands or butt, so I dont think its front suspension or rear related, but that is possible.

I initially thought it was the kickstand bouncing up and down, and I havent cancelled that out yet. But i did ride once and keep my heel on it and still felt it. It was a little scary to push harder down because it would kill the bike. :)
 

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Discussion Starter #18
real low, parking lot speeds. maybe 2000??! I dont ever look at rpms down that low. basically as slow as you can go without falling over. :)
 

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For me it's only felt as I pull onto our drive when I've got the bars on full lock to the left. Or when I'm turning a really tight left hand bend and I'm going dead slow. I've only ever felt it through the left hand foot peg.
 
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