Welll how self-motivated are you? And what do you prioritize: the fresh air and real biking, or the benefit from training with others beside you?
You could get the best of both worlds if you join a cycling club.
But remember you WILL have to buy yourself a bike before the event anyways won't you? If you will need to invest at some time, why not buy one now to make full use of it and get comfortable with long distance cycling on your own bike? who knows if you'll want to get new stuff for you bike before the long race.
To be comletely fair I don't know too much about how long you will be cycling in the race, but to my understanding its a mixture of swimming cycling and running, much like the ironman. If it is anything like the ironman, I strongly suggest you get comfortable with your bike before the main event.
Best of luck, wish I had the time to do it.
[edit: oh ****, well I'm an ****. lol. anyways I still suggest joining a cycling club, you'll immerse yourself with other likeminded individuals who think that health means more than 30 minutes on the treadmill.]
Last edited by emerset; 08-07-2012 at 13:16.