Re:xp 900 ranger tire size
Well the best way is to leave everything stock. But if your looking at bigger tires trying to not lift the bike any will go the farthest to eliminate greater axle angles. If you run forward a arms instead of a lift on a ranger you can fit bigger tires than you can with the lift and not increase angle angle over stock.
Now if your mostly doing trail riding over mudding i would suggest doing 28s over 30s. Lighter weighted tires will do nothing but help drive train compared to bigger tires and if your really not needing the extra GC for mud then to me 28s are the way to go.
2013 Ranger XP 900
BA front and rear arched arms, brush guards, ssv radio, 5000lb Viper Elite Winch, 28" OLRs S/W, front and rear poly windshield and roof
2011 Ranger XP
Front and Rear Brushguards, JStrong Roof, Super ATV Forward A-Arms, JStrong Folding Windshield, 27" Mudlite XTRs of ITP SS212 Rims, 4500lb Polaris Winch, Rear Box Rack.