Got a long riding event coming up - but only ever trained short!

[Tragesty]

Hey guys, need a little bit of help.

I got my mountain bike around nine months ago and have enjoyed cycling of all sort ever since then. Nearby my home is a little cycling track that's 4KM in distance, and every couple days I've rode it. Gradually over time, I felt it getting easier and as such now ride at the highest gear as hard out as I can over the 8KMs to get my legs burning and the like.
My legs have definetly gotten stronger over the last several months, but the Victorian Bike Ride is coming up in November, and it's a (recreational) ride over nine days covering a total of 600km.
What worries me is that I've always known that sprinters aren't going to be good at long distance and vise versa, and would the same apply in my situation? My legs have gotten stronger but would that be quite irrelevant when I'm riding around 70km a day? Should I start riding that 8KM trail multiple times or is it okay if I stick to, well HIIT almost - I hit my legs hard for a rather short duration, rest a bit, then go hard out again.

I hope what I'm asking isn't a big bundled mess and appreciate any help fellow cyclists could give.

- Michael.

 

[jhuskey]

Looks like a great ride for all abilities any training is better than none. I know you don't want to read this but this looks like a road tour and although a MTB will make the trip you would be way ahead on a road bike in comfort, speed etc.

 

[vspa]

you are still in time for November but you should train differently from now on. Increase to 30 kms every training ride, so 8 turns the 4 km track... at least ! for that you need 1 1/2 hours,

 

[kdelong]

+1 and +1. Both previous posters are right on the money. A road bike would make the overall ride much easier as long as it is all on pavement. And you now need to be training for endurance more than leg strength. The only way to do this is to ride longer distances. Start doing the 30km rides immediately, and then on your days off from work, get in increasingly longer rides until you reach 70km. But don't forget to take one or two days off from training each week or you will begin to lose your gains.