I get an intermittent vibration noise on pedalling on my road bike. It happens seated or out of the saddle. Does not happen on freewheeling. It’s more apparent on poorer road surfaces and when I’m putting in big efforts out of the saddle. It’s not the pedals.

It does not sound like the BB. Chain is properly lubricated as are the jockey wheels. The sound is like intermittent Mavic death rattle – for those of you familiar with that noise (Mavic DR happens on freewheeling and non lubricated hub internals).

This one has got me scratching my head.

Any ideas?

What have you changed recently? Or fiddled with?

Is the noise a regular frequency when it’s present? Does it change with pedalling cadence?

First thought is chain routed incorrectly or rubbing on the derailleur.

Not changed or fiddled with anything.

It’s not regular when it occurs. I’m running Dura Ace di2 and the chain is shifting perfectly.

Your knees?

Yes, could well be my knees. Everything else is broken….

Slight chain rub on the rear mech cage?

Broken jockey wheel?

Any particular gear combinations?

Recently had a similar instance on a customers road bike, turned out to be the freehub body bearings ….after checking just about every other moving part on the bike. Wasn’t initially very obvious at all.
Worth stripping to check though.

I had a strange buzzing/vibration when I swapped the tyres, from 2.8 to 2.4, when leaning into bends. Went away as quickly as it appeared when I swapped back

Any chance you’ve misthreaded the chain over instead of under the tab between the jockey wheels ?

I reckon trisysjoint maybe into something. When the bike shop checked the bearings they said they were not aligned properly and put them back correctly. I think they may have worn. It’s being checked again at the LBS next week.