[McBob]

Rear upper head steady is cheap pressed steel and fractures easily. If it has failed, replace it with  a stainless adjustable version from Hitchcock

The head steady! Will check it, thanks!

[McBob]

I had a petrol tank rattle on my 2010 C5. Nothing I did fixed it until I actually removed the front mount bolt entirely to discover it was a long, thin M8 bolt. The rubber grommet and the metal tube that goes through it was large enough for an M10. So I went to my local fastener shop and bought one, it slid right in with a little bit of resistance, and the rattle went away.

Interesting, but my tank is the newer kind, with the twin bolts on the seat side. Already checked. Thanks though!

[McBob]

The silencer heat shields are well known for rattling.

I've inspected it from below, and, yes, it seems like the clip holding the heat shield to the pipe is missing. Maybe it broke and it has slipped
further towards the silencer? I've to schedule a heat shield removal session... Thanks.

[Mad4Bullets]

With that front clip missing from the heat shield, they rattle like hell, but only at certain frequencies. Put a few turns of bailing wire around the front end and go for a test spin. That was an early source of a severe rattle on my C5.

[McBob]

...but only at certain frequencies.

THAT would explain a lot of things. Funny how the noise seems to come from around the fore left indicator
(which I checked and it's OK). But I know noises on a motorbike are always from elsewhere...
Thanks, let's try it! But, do you think a heat-resistant rubber thingy put between the pipe and the shield
would be ok (instead of the wire)?

[Ove]

https://www.martins-rubber.co.uk/blog/guide-to-high-temperature-resistant-rubber-materials/

[Mad4Bullets]

For testing purpose I repeatedly folded a piece of aluminum foil and formed it to the diameter of the exhaust header.  Then I just pushed it snugly into position between the header and heat shield with a wooden skewer I had on hand.  That was a enough to take it out for a test ride and verify the problem.  Ultimately my solution was to replace the entire factory exhaust. ;-) Could this all that's needed to foil your vibration issue?  See what I did there?

[McBob]

For testing purpose I repeatedly folded a piece of aluminum foil and formed it to the diameter of the exhaust header.  Then I just pushed it snugly into position between the header and heat shield with a wooden skewer I had on hand.  That was a enough to take it out for a test ride and verify the problem.  Ultimately my solution was to replace the entire factory exhaust. ;-) Could this all that's needed to foil your vibration issue?  See what I did there?

I see it, perfectly, thanks. I was thinking more of a homemade HT silicone plug (while I'm at it, I could also make some gaskets for the heat shield screws, although that might be overkill) - as also per Ove's comment. In the meantime, I've also purchased a metal strip to bend, cut and recreate the clip.

[McBob]

UPDATE

I don't need (yet) to re-create the clip! I removed the heat shield, and it was there (the clip), in pristine conditions, never
hooked. So that's what probably made the whole contraption rattle. I hooked it, had some difficulties refitting the
heatshield because all screw holes were slightly off-center, and I also inserted, for good measure, the HT silicone plug.
I'll probably take the bike when I go pick up my son at school. Lord, please, let the rattling be thus ended.

[Mad4Bullets]

Let us pray, the problem is resolved.

[McBob]

Sweet Jesus, IT WORKED! Hallelujah! Begone, rattling noise! Or, should I say, begone MAIN rattling
noise. Without that racket, that is, I now perceive something smaller. But I already have three suspects.

Look:

1) the front caliper brake hose clip. It constantly comes undone. And the rubber piece touces the mudguard rim!



2) the headlight. I switched the original bulb with a Ballack yellow anti-fog one. Where I live is often foggy, and
forget about the retro look (although, well...) - it works. But there is probably some casquette re-arranging to be done.
Because, as you can see, it doesn't close perfectly.



3) the possibile culprit: that bunch of really tough, springy cables in the middle, held by the plastic band - I guess they have
something to do with ABS, but I could be wrong. They vibrate against the tank rim, and I believe the tank resonates. If I, while
running, put a hand on the tank, the rattling subsides, and almost vanishes. As you can see, they are even slightly
dented at the contact point!



I'm optimistic. Without the main rattle, the bike is another bike. And I love her even more.

[Carlsberg Wordsworth]

Keys in the ignition?

 If you have only one, well it's not that

[heloego]

Pic #1:
That steel tab looks like a modified side box lock tab and shouldn't be there. It will NOT hold the cable as needed.  Go here:  https://www.hitchcocksmotorcycles.com/partsbook-pages/4976.
See item #10.  This part can be ordered directly from Hitchcocks (our Host), or from Tim Hirdler at https://westerncyclesupply.com/. Phone #: 1.682.730.2705


Pic #2:
Your clip may simply be too long (maybe wrong PN). Go here: https://www.hitchcocksmotorcycles.com/partsbook-pages/4976.
Or call Tim.
See item #11. Or you can easily modify the existing clip if you have a vise and a hammer.

Pic #3: If the rattling stops as soon as you put your hand on the tank it sounds like you need to tighten the fore and aft tank mount bolts.

[McBob]

Keys in the ignition?

 If you have only one, well it's not that

Well actually I got three (ignition, helmet hook, disk brake lock) and they ding-dong-ting-a-linged a lot, then I covered them with
pieces of clear rubber hose and they stopped. Thanks, though.

[McBob]

Some interesting tips heloego, thanks.

The steel tab in Pic #1 is actually part 1010180 (my C5 is 2018) although, since it doesn't perform as expected, I will consider
swapping it with "old school" item #10 (but I would have to learn how to install it - you should have that on your 2012, how about posting
a close-up? That would be enough, I think...).

I will also check the headlight clip - I totally ignored they existed in different lengths!

As for the tank, I already tightened the tightenable - I don't have fore and aft bolts, just twin aft bolts and they
are factory-rubber-gasketed as they can be... As soon as it stops raining (here), I'm gonna neoprene the heck
out of the springy cables and see if the rattling stops. Further evidence against them is the fact (as my son
pointed out while on the pillion) that with a less-than-half-full tank the noise (although, remember, slight) is
more evident. Almost empty, it (the tank) sure resonates more.

Sooner or later, all I'll hear while riding will be the thump and the valves. Oh, glory be!