Its all about frame height. You can put bigger tyres on and lower the suspension and make it handle better than the stock setup.Does the larger tire/wheel make it more top heavy, and or not as stable? Someone told me not to go bigger cause of this. Cheapcycleparts.com had a 14x8 set of rims with tires they said would fit the 700XX for under $300. I was thinking hard about getting, they are no longer availible.