The Hour Record

Nah it was reverted to Sosenka's record, so some of the Boardman/Obree records stood, others didn't.

Someone will correct me but I think they decided that it had to have been set on a pursuit legal bike at the time the record was set.

Nope, nothing as logical. Boardman's 56 was on a perfectly legal pursuit bike. They just said "whatever we've done before, here is our current recognised record (Sosenka's), and we're letting you beat it on any legal track bike". So whether Boardman's/Obree's records "stand" or not is a bit of a moot point; Boardman's 2000 "Merckx" record "stands" cos it has never been annulled, but all his others were obliterated when they made the "Merckx" rule-change. No records got 're-instated' with the latest change, so it's not a case of some records standing and others not; all of Boardman's/Obree's records (except 2000) were further than Sosenka in any case.

What I've not heard anyone talking about, though, is whether Rominger's bike would be pursuit-legal these days and if not why not; seems to have same-sized wheels and standard bars from what I've seen. -- Not that this has any bearing on the record, but if we say Boardman's record is unobtainable due to aerodynamics, what about Rominger? i.e. How much dope is required to ride a standard pursuit bike that fast for an hour?