ok right now i have 2.5 street tires on my bike.
sit down tight circles i have no problems with the tire, but when i am doing standup tight circles the tire wants to keep giving in and buckling up.

i have plenty of air pressure in the tire, almost max.

my tire needs replacing about now anyways, and i was thinking of going to 2.75 or 3. Do these bigger tires help out when doing tight circles when all the weight is on the back wheel??

 

I run a 3" but only thing I really like them for is reallllly tight reallly fast circles.. they dont slide out as much

 

i would go with 3.0's i run 2.5's and like nags said they slip out on me when i do circles

 

Well, the only time the 2.5's slip is when I'm doing them really low and fast.. for anything else I actually prefer the smaller tire