[Closed] Diagnosing a Creak

Mine did it a bit when coasting on rough ground as it must have been rattling, but climbing and pedaling was the most obvious.

When I put the bike on its side and moved the mech by hand I could feel it.

Seat tube again. Lubed up rear mech to stop it creaking, then pushed down in the middle of the bike only to get the cracking/creak noise back.

Undid a few bolts and tightened them back up (one was that tight it gave off a spark as it freed up!).

Finally undid the seat post clamp and it quietened down. Took the seat post out and tried without and there was no noise.

Re inserted seat post and it seems to have gone away again now.

Possible that the seat tube is ever so slightly out of spec?