Important Race-4 weeks to go

you don't neeed to worry too much (if at all) about endurance. On a flat course 65km will go by in 90 minutes. As you'll be in the bunch out of the wind for most of that you don't need to worry so much about going flat out for 20 minutes, or "time trial" training....unless of course you're planning to try and solo to victory with 15km to go.

If I was you I would work on sprints, and short intervals at your maximum. This is to simulate the surges in acceloration that occur in any race.

In fast group rides drop off the back deliberately and force yourself to chase back on (gives a sense of reassurance about getting dropped) and mix that up with riding off the front and trying to stay away.

Above all you shouldn't need to train more than an hour and a half 4/5 times a week, (one light recovery session) but you should be ripping your legs off and pushing yourself into the pain zone several times a week. You need to be simulating sprinting hard for longer than you thought you could, and then do the same again without giving yourself nearly as much recovery as you think you need. Repeat, repeat and repeat. Seriously - I do up to 50 hard 15 second sprints in a good session. If the race has lots of corners that everyone will be flying out of you need to be able to match the accelorations or you'll lose ground on every bend and get dropped early on.

I find that in the 7 days before a race I train hard or do training races until 3 days before the ace, then take 2 days rest. The day immediately prior to the race I will do some sprints and short intervals for an hour or so to warm the legs up or, preferably, I will do a training club race.

If you spend your remaining time doing 4 hour rides at a sustained level of intensity you will run yourself down and will have no speed come the big race. Less is more.