Lots of long low intensity rides of up to 5-6 hours to get you used to staying in the saddle for a long time and improve your endurance. Some high intensity rides (hill reps and sprints) maybe once or twice a week building up each week but the type of event you are doing endurance is the main thing you should be concentrating on. Also try riding two or three times a day/evening to get your body used to the type of riding you’ll be doing as well as night rides. Above all plenty of rest inbetween.

You can boost your top end and recovery quite markedly in six weeks, but whether there’s much point in doing that depends a bit on how you’re intending to ride/race. Pairs is quite brutal because you never really get a proper rest, well, if you run doubles you get something like it, but anyway, that’s tactics not training.

Try doing some brutal intervals, say 20 second hill sprints with 40 second recovery between reps, five minutes between sets, three of, followed by a steady road ride, say 90 minutes. Then up the intervals to 30 secs with 30 secs revovery followed immediately by a two-hour steady, just a couple of times a week.

But really, you’re best off consulating a coach. Or… oh it’s pointless really :-/