Metallic 'catching' noise when 'grinding' or standing on pedals?

[silva]

It could be the handlebars mount too, since when pushing legs, you pull there.
Alike a kinda 'knee" in the its mount, used to adjust the elevation / angle of the handlebars.
Such system I had, aluminium, the gripping surface (to prevent slipping) were 4 or 5 horizontal ridges.
Their ends wore, allowing a little movement, aggravating the wear. It also made such metallic scraping noise.
In the end I discovered the cause, due to feeling the handlebars play, that got worse enough to be noticable.

 

[Sloth]

I think I have solved it.
I think it was the front disc catching, likely from frame flex, combined with perhaps downward pressure from leaning on the bars, as I was pushing down hard, standing on the pedals to 'grind' uphill.
I think the front wheel straight through bar was over tightened, as since removing the front wheel (to transport to the LBS) and re-fitting it has seemingly cured it.

On another issue, There is still some slight chain rub noise but only when I'm in the largest 42t rear cog, far less in the next one down, but perhaps there is no way to avoid that in the extreme chain angle position/s, even on a 1x?

I also note some strange 'rumbling' or 'throbbing' noise/sensation, when moving at a pace in the smallest 11t rear cog. I am not sure what that is, but as I say, it's as much a 'sensation' through the pedals and seat as it is a sound. It's as if something is slightly out of true, rather than catching.
Neither of the above impact on my ride, just a little odd I suppose.

 

[ColinJ]

I think it was the front disc catching, likely from frame flex, combined with perhaps downward pressure from leaning on the bars, as I was pushing down hard, standing on the pedals to 'grind' uphill.

Fork flex? Combined with pads very close to disc. That's what I get on my bike.

I think the front wheel straight through bar was over tightened, as since removing the front wheel (to transport to the LBS) and re-fitting it has seemingly cured it.

I would have thought under-tightening would be more likely to cause problems like that!

 

[Sloth]

Just theories, others are available!
I'm basically guessing but will take the win that it's not happening now.

 

[SpokeyDokey]

Re 'slight chain rub' & 'rumbling' noise. Maybe ask the LBS to double-check the chainline is within tolerance.

 

[Sloth]

Re 'slight chain rub' & 'rumbling' noise. Maybe ask the LBS to double-check the chainline is within tolerance.

Is that a thing with a 1x set up?

 

[SpokeyDokey]

Is that a thing with a 1x set up?

Maybe, not entirely sure. Worth an ask?

 

[Sloth]

Well the metallic rubbing noise has now stopped since I checked the front wheel bolt tightness.
However, I now have a funny clicking, no more of a cracking, creaking noise from the front or possibly BB area. Again it’s only (or mainly) when putting some heavy force into the pedals (I think) and I’ve tried checking for knocking cables, etc and even packed out my small saddle bag in case something inside is rattling about, but to no avail. I don’t know if it’s ‘normal’ for a carbon frame bike and something one just has to live with, but it didn’t do it before, and it’s too new with too few miles on it to be a cracked frame surely?
Same for the BB, but it was replaced under warranty only a few months ago with little mileage since (compared to you guys at least), so surely it shouldn’t be that?
It’s only started happening the last couple of weeks, since the bike was converted by the LBS from a 2x 105 (34/11) to a GRX812 1x (42/11) in which the chainring and cranks were also replaced from 105 34/50t to a 42t GRX. The BB was not replaced though as it was apparently fine.
Any ideas?

 

[sevenfourate]

Any ideas?

Yes.

Take it back to whoever did the gear set conversion, tell them your issue and ask them to investigate. If it wasn’t doing it before - but has since - it’s very likely something they have or haven’t done……

 

[Sloth]

So I removed the carbon D fuse seat post, wiped it, applied carbon gripper paste and refitted to the correct torque.
I went for a ride today, and it still does it.
I’m convinced it’s when I pedal hard either in top gear or uphill.
Bumps do sometimes make it happen as well though. So perhaps hard pedalling causes more movement and flex, which has the same effect as a bump?
Anyway I checked my handlebar bracket bolts and could easily tighten them a fair bit before they were hard to tighten. Same for the headset bolt on the top, and the bolts on the side of the headset, and the same for the pedals (bolts on the ends of the pedals), and the bolts holding the crank arms on.
So all tightened up and ready to see what happens on the next ride.