Originally Posted by
cruiserhead
27.5 will be the new standard for mtb
Giant is moving towards that, not just in women's bikes but all their mtb's
29er's will still have a place but not as widespread
29" is still the standard for cross-country mountain bikes and will remain such. 27.5 is definitely coming into XC, but it seems likely to be most popular in the trail/all-mountain segments. Probably enduro, as well.
No one should worry about 26" tires going away. In mountain bikes, it is still the preferred size for downhill riding, outside mountain bikes it remains an extremely widespread and popular size.