I understand your need for ecomony and if your current bike gets from point to point OK, then ride the heck out of it.
As the poster above stated, save up for a good Craigslist bike. Look for a good frame and rims. Then upgrade that bike. Other than just maintaining your MAGNA, save the money. Upgrading it is like putting lipstick on a pig.
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I think its disgusting and terrible how people treat Lance Armstrong, especially after winning 7 Tour de France Titles while on drugs!
I can't even find my bike when I'm on drugs. -Willie N.