Pretty sure the triangle is car only, not bikes...
Anyway here's what I take:
Passport (+photocopy)
Driving licence (+photocopy)
Bike Docs (+photocopies)
Insurance docs (+photocopies)
Travel insurance docs (make sure the insurance covers the size of bike you ride)
EHIC card
Green card if going into Spain (not really needed but better safe ...etc)
Two wallets (one with some large notes and a credit card, this is your emergency stash) The other wallet is your normal one. Don't keep them together.
Spare keys (find a good hiding place on the bike for these)
Mobile (+ a spare battery for it) (put a ICE number in it)
2 cards with all important UK numbers written on them (put one into each wallet)
Sterling, Euros etc.
Maps
Crossing details (bookings if made)
Small French dictionary
Small Spanish dictionary (if going to Spain)
Spare bulbs
Spare fuses
Small First Aid kit (Blacks etc do them)
The rest is really down to you as far as clothing, GPS's, iPods, cameras etc, etc.
Have fun