Something rubbing - help!

Ok one last guess for me. Worth a check is whether there is anything sticky between your inner tube and tyre. This could cause the noise to coincide with wheel tuning and weight on that part of the tyre/tube (or as the wheel rotates and weight comes off). Its an easy check.

Clothing? Something was driving me nuts for weeks and I finally found it to be my long laces slapping against my shoe as I pedalled.

It's unlikely, but check the frame for cracks around the bottom bracket, and the chain-stays and the seat-stays - it is just possible that a crack could open up under your weight and cause the rear wheel to move enough to rub against a brake disc. I hope this isn't the case!

Thanks lasers. If gt101 is same noise as mine? I haven't discs, brake pads well clear, the only expensive wheels I own, smooth as silk to spin without grounded weight yet rub, rub, rub noise once underway. I gave up trying to understand such, weird as???
Off to hand feel the spokes... I swear it's gotta be a bearing though and being sealed units I guessing it won't harm the hub.

That's a downside of cartridge bearings, they don't last too well in wheels. I noticed my front wheel rocked side to side when seting out a couple of evenings ago. The bearings were toast, one was smooth but was noticeably loose. The other had got water in and rusted and was rough and seriously loose. I replaced them myself with standard SKF bearings, about £4 each. They had 1,816 miles on them and are never jet-washed.

One of the brake discs is likely out of true, but by a tiny amount too small to see with the eye.  You can easily test this by removing the pads and going for a short ride (or if it's the front wheel just reverse it, making sure it doesn't foul the fork).  You can also look on the caliper, perhaps the disc has a wavy edge that's just slightly fouling the caliper (you'll see bare metal where it's worn the paint).

It's extremely unlikely to be the bearings, but you can confirm this by grabbing the wheel rim and pushing it side to side.  Worn bearings will mean the wheel hub can move on the axle.  Ceramic bearings are a waste of money, just stick with regular steel bearings.

One thing I can think of that would change when you are on the bike to when it's in a stand is the front suspension. Maybe the front hydraulic hose is bowing into towards the wheel enough for it to rub on the tyre when the forks are compressed? Has a hose clip come off or moved maybe.

Edit to say, I just looked at a picture of the cable routing on a Badboy and it looks like it runs internally from the caliper up the fork leg, so scrub that!

If it is a bearing, what's a decent material?
Reading about ceramic and harden chromoly(might be wrong).
Not sure if ceramic balls will break in not always just to roll on wheels.
Guessing from the price that ceramic very smooth.

Loose wheel bearings?

Loose spoke/s

Your bike has been possessed by Satan. Time for a new one.

Loosen off a brake pad, go for a steady ride, listen. If still noisy, tighten back up and try the other.

It's often about eliminating a thousand things to find the one...

Do you have mudguards? My winter bike does that when the tyre picks up a bit of sand or leaf - makes a 'tsh' noise as it goes through.

Lol. Mine does the same. Brake pads are clear yet front hub is a 'copter.
I guessing mine is bearing 'cos not much else. No noise with no weight.