lets see...

Original cost: $690 in late 2007.
Using MACRS, it has 5 year useful life, if we call it transportation.
First year depreciation: 20%. The value of the asset in late 2008 was $552
Second Year depreciation: 32%. The value of the asset in late 2009 will be $331.20.

The use of the bike so far has been 358.80
I've biked about 3000 miles with it.
I go through 1 $3 tube every other month (12 total): $36
tools, etc: $100
Shoes, pedals: $100
Jerseys, shorts: $200 (I'm cheap)
Helmet was an accident replacement a year ago: $0

Need to buy new tires this month, so I'm not including that for now

Total cost: $794.80
Cost per mile: $0.265

Bike race fees aren't bad compared to car race fees... And the disposables are much cheaper.