Where is this ruddy noise coming from!

[Brianjeff50]

I’m increasingly baffled by the source of a mystery tapping noise on my bike. It’s roughly once every revolution in most gears and both rings but only on moderate loading. It seems to be from roughly the BB area.
The bike is an Enigma Etape with Absolute Black Oval chainrings on Ultegra cranks.
I’m embarrassed to admit that I let the chain wear more than I realised and only replaced it when gear selection started going a bit wonky. It’s since then that the problem has arisen.
The gears shift perfectly, I’ve checked the FD alignment and the condition of the outer chainring (some teeth looked worn but AB assured me they were just shaped to facilitate shifting).
I can’t replicate the noise on the stand and there are no obvious signs of wear in BB or pedal cranks.
Any ideas?

[mattsccm]

Pedals or cleats? More pressure might stop it but just cruising along might not.

[peetee]

Can it be felt as well as heard?
Is it a ‘ting’ or a ‘tick’ or something else more ‘wooden’ sounding?
And was the chain replaced with a quick link or pin?

[Cyclothesist]

I suggest you work through the possible causes using this website as a guide:
https://www.jimlangley.net/wrench/keepitquiet.html

[rareposter]

Stiff link in the chain?

Basically you've changed a worn chain but not the cassette, jockey wheels or chainrings so there's almost certainly some minor incompatibility somewhere - there's likely to be a couple of worn teeth somewhere or the new chain has a stiff link or is maybe catching or snagging somewhere on a fractionally hooked cassette or chainring tooth.

If you still have the old chain, try refitting that and see if the problem still exists.

[Jdsk]

I suggest you work through the possible causes using this website as a guide:
https://www.jimlangley.net/wrench/keepitquiet.html

Thanks for that. Looks very helpful and deserves further study. And discusses the use of a stethoscope.

Jonathan

[Brianjeff50]

Stiff link in the chain?

Basically you've changed a worn chain but not the cassette, jockey wheels or chainrings so there's almost certainly some minor incompatibility somewhere - there's likely to be a couple of worn teeth somewhere or the new chain has a stiff link or is maybe catching or snagging somewhere on a fractionally hooked cassette or chainring tooth.

If you still have the old chain, try refitting that and see if the problem still exists.

Can it be felt as well as heard?
Is it a ‘ting’ or a ‘tick’ or something else more ‘wooden’ sounding?
And was the chain replaced with a quick link or pin?

The noise is closest to a metallic tap and the new chain was shortened then fitted with a quick link. The old one went in the bin!
I can’t feel any snagging when pedalling. I can’t see any stiff link and I’ve given it fresh clean and lube to no effect. I’m guessing the likeliest solution is a slightly hooked chainring tooth rather than cassette as it’s in multiple gears - but I think it’s in the smaller ring too - though I’m usually straining up a hill in that.
I’ll go through cyclotheist’s helpful faultfinder.

[hamster]

Seatpost rails? Seatpost? Loosen, move a little, move back, retighten.

I had the same maddening one on my Litespeed. It turned out to be a tiny bit of muck in the rear dropouts. Cleaning the axle tips and dropouts did the trick. The tick-tick used to appear every winter. It took simply ages to track it down the first time.

[531colin]

………..It’s roughly once every revolution in most gears and both rings ……..

If it’s precisely once every revolution that takes you to pedals, cranks, bottom bracket and all the stuff which moves when you shift your weight; saddle, bars, even axles moving in dropouts…..
Roughly once a revolution is less helpful?
I had a square taper crank which clicked at no particular point when the left bolt wanted nipping up

[KM2]

Are the Ultegra cranks, the ones on recall. Glue problems

[Brianjeff50]

Are the Ultegra cranks, the ones on recall. Glue problems

Fortunately not.

[axel_knutt]

Gear cable nipple catching on the crank?

[Paulatic]

^^^^^^^^^^^^^^^
I’ve had that noise catching the shoe.

[peetee]

Are the Ultegra cranks, the ones on recall. Glue problems

Fortunately not.

There are reports of this happening to later cranks too.

[TrevA]

Check your chain ring bolts. I had a similar noise, checked the bolts and found that one was missing! Bought some replacements and they are now all tightened up to the correct torque. No more noise.