tyre is just as 'fat' on the 26" you just dont notice cos its also bigger (obviously) but yea, mod, stock, 24" are all 'pro' bikes. none are specific beginers, there are begginer mods and stocks i.e. t-vee, t-bird, zoot, t-rex. all starter bikes, although the rex probly isnt the best exaple, but most well known so meh