so I am thinking of buying a hardtail mountain bike for use as a commuter and also maybe racing some cyclocross for fun and training over the winter.My full suspension race bike is not so good for that stuff. I have found a bike that I think would be suitable for this purpose it is light and cheap and has a frame that is easy to shoudler....however, it has mountain bike chainrings....what is the biggest toothed chain ring and where can I buy it for shimano mountain cranks?