I’ve never ever had a rattle they’re simply not allowed, but this just popped up last Sunday.

It’s at the rear, it sounds like a whole lot of cable outers banging against the frame.
I gave it a once over, I couldn’t replicate it by bouncing the bike! Everything was tight except the cassette, that had movement. I removed it thinking the freehub would have play, but it didn’t.
All cleaned an reassembled and it still does it.
I also need to replace the cassette and chain anyway, but I’ve never had this.
Is there anything you can think of? plus these are the only sealed bearing road wheels I’ve owned, is rattle a characteristic of these?
Ta.

Rim joint?

Cassette lockring, chainring bolt, loose valve locknut.
Or… Rattly knees.

Definitely a rattle…?

I was once deceived into thinking I had a rattle by little particles of grit getting flicked-up by the tyres.

Is it definitely at the back? I had a weird rattle recently on my MTB, was trying to work it out for half a ride until eventually I tried to go into granny and the chain came off. Turned out all the inner chainring bolts were loose, I’d lost a couple and my granny ring was flapping about!

Loose nipples?

It’ll have to have a full inspection Monday. Rim joint **** me 😯

Loose light mount or similar? took me an embarrassingly long time to find

Mavic hub?

I had a rattle. Turns out I forgot to put the thin spacer back with the cassette when swapping it to another set of wheels.

MM

Small change in pocket?

As someone mentioned – thin spacer on the cassette missing? Mine rattled like crazy when I forgot to put it back on!

Venomous North American snake wrapped around the seat tube?

Most bike noises can easily be remedied with headphones.

It’s not something on your helmet is it? 😀

Not a missing spacer, but there is play between the cassette and freehub, though you wouldn’t think it would rattle when under tension?

Bottle cages on tight, not rattling around?

Are you sure 😉

Goes on before the cassette

valve stem rattling in the rim?

This was the cause of my last random rattle 🙂

Snake bite puncture?

… i’ll leave…

Not a missing spacer, but there is play between the cassette and freehub

Something’s wrong there then! Only the sprocket with the chain on will be under tension with a missing spacer – the rest will jiggle about.

The little locknut that you screw down onto the rim against the valve stem.
That’s a total pain to track down but such a simple thing.
Loose spokes.
The frame flexing under the sheer power that you’re putting through it? (my personal favourite, that one).

Did a Sportive yesterday and overtook a guy on a carbon Giant – the bike was making one hell of a creaking noise. Turned out to be the seatpost in the frame, carbon paste must have all dried out or he’d put it back together dry. Sounded awful.

Air valve locking nut loose?

My guess’d be missing spacer behind the cassette.

New cassette and chain, no rattle.

Registered just to say thank you to stufive.

Rattle has been bugging me on and off for weeks now.

Both air valve lock tightening nuts were coming away from the rim enough to give a little buzzy rattle every now and then.