What size rear sprocket?

[GoinPostal]

I am building a Badlands ST2 running a 05 CBR 600rr motor. I need to purchase a rear sprocket, but not sure what size to use. I wanted to run a 60 tooth rear and 14 tooth front, but was told a 72 tooth rear would be much better. My concern is the size difference in the sprokets. I want as much travel as possible and I know the larger sprocket will hang down more. Any info will be a great help.

[plkracer]

I am running a 13/60 combo with my 750, and it is nice. I can take off on a level surface at idle and turn lock to lock on asphault while idling. It is a little faster than walking speed.

It mostly depends on tire size. I am running 25.5 inch OD tires but plan to go to 27's. If you are running anything near a 30, you need the 72.

[GoinPostal]

I am running 28 inch tires, dirt and sand. It sounds as if the 72 will get more more bottom end power, which I know I will need. Anyone know where to get a custom sprocket cut? I need one for a 4 bolt, 115 milimeter bolt pattern, 1 3/4 inch center hub. I made a carrier out of a car hub that went to a 280Z and wanted to use its stock bolt pattern for the sprocket.

[punkur67]

Go as big as you can afford for space. Even with a 72 top speed will not be an issue. The bigger the more bottom end. If you can try to drop a tooth in the front instead of going bigger in the rear. Also keep in mind that the closer the sprockets are to eachother with a large rear sprocket the less teeth will engage the chain in the front.