> and I'm sick of these groups knowing my details (which as we all know get passed on and turned into spam that comes back to haunt us)


All that Google will know about you is the email address you use to sign up with. Note that Google does not sell your personal information to anyone.

> unless there is a more direct site


https://groups.google.com/forum/#!forum/tramsdownunder is the direct link to the TDU group.
Best wishes,
Malcolm