Checked with the organisers - you don't need mudguards.
Went out with some lads at the weekend and we are definitely doing it if anyone wants to join us - we aren't super fast (or even normally fast) none of us compete beyond the odd tri or club10 - although a couple have raced in the past.
It is pretty hilly even by Derbyshire standards so I reckon you'd want a 39*24 or lower gear - depends on how you like to go up hills I suppose but don't bring a fixed.
Our next ride should be in about a month and around Notts or Leics if anyone is interested - it's just a group off the equivalent cycling+ forum.
