Ok guys, I am new so forgive my ignorance. I have been doing lots of research and am very confused. What exactly defines a bike as a 29er. Is it only the tire/wheel size or are there other things also? for instance while looking at Treks website I noticed that some of the "29ers" have 700c size tires. There are other bikes also such as the DS series that also have 700c size tires so would the DS series technically be 29ers? Sorry for what is probably a basic question but I have search high and low for the answer to no avail.