I'll save you the long, drawn out report and just give the short details.

Chose to ride D Grade since this was my first Road Race. Only 6 people signed up but it was still a good ride and an even better test. I finished first but it also showed how bad I am when it comes to getting up those hills.

Average: 31.2km/h
Max: 59.9km/h
Distance: ~55km/h
Time: ~1 hour 20 minutes

Looking forward to giving it another go. I'll probably take a swing at C Grade next time.