Just got a new 1" threadless headset (a madison cycles sealed cartridge system) and upon removing the old one I've run into a problem.
The new headset cups just sit loosely in the headtube. i.e. I can push them in and remove them by hand.
Also the crown race is abit too big for the fork. When compared with the old headset cups the new ones look almost identical in size. I havn't ruined/ovualised the head tube as when i tried to refit the old cups they're tight as a headset should be (would required a headset press to install).
It's as if the crown race is a size up and the cups a size down, although I didn't think headsets came smaller then 1inch. I've tried searching the forum and all I've found is that there are some old bikes which take a cup afew mm bigger then standard..The frame is a fairly good make and new enough so I didn't expect to run into complications with this..

Has anyone experienced similar? I've heard using red loctite can help but the play in the crown race is too much for that I think..

The only other explanation I can think is that this is a sealed cartridge bearing headset(old one was a standard ball-bearing race headset) and uses a "clamping" system..(that CAN'T be right can it?)

Any help/advice appreciated..Should I just return this and get a better headset..?

I'm no expert, but there are a lot of nominally 1" sizes for headsets. People are going to want more information here (your frame, old headset, etc)

Sorry,
the new headset (never head of it before, got it from a friend) is a "madison cycles 1" sealed cartridge system headset"

the old headset is an aheadset 1" threadless headset

the frame is a terry dolan track frame..I'm not sure if many people outside the UK/Ireland are familiar with this brand but they're generally well known as quality frames and were (are?) used by the Irish and English track teams..website link- https://www.bikes-dolan.uk.com/
I bought it off a friend a few years back and I'm not exactly sure which model..

hope this helps, thanks again