They're not welded, they're either pinned or sleeved. There's a couple of hundred Newtons of hoop compression pushing the two ends together, so nothing to worry about.
Thanks as ever for answering all the inane queries. Building a bike has thrown up so many questions which I usually have a rough answer to but you never really want to fuck with 'maybe' when getting it wrong means possible dental implants and half a year of recovery..
They're not welded, they're either pinned or sleeved. There's a couple of hundred Newtons of hoop compression pushing the two ends together, so nothing to worry about.