Same circumference as 29er, wide 650b rims, bigger air volume = lower pressures = more grip and comfort. That's the theory anyway. Can be retro-fitted to some 29er frames, albeit using smaller 2.8" tyre, not true 'plus sized' ones of 3" and above.
I fancied that marin, but fancied the trek more! The marin is also 32lb stock, which shouldn't bother me, but it did......plus, I couldn't find anyone who had actually ridden one before.....and I know I like my buddy's krampus.
thinking about the new marin pine mountain 1 for next year. What is all this 27+ about? I was just getting my head around 29er..