The amount of space you lose in the tight stuff is too great compared to the amount you gain back on the straightaway. So in that situation removing a tooth (11-79) might give you the top end you need without sacrificing too much bottom end. The best rule of thumb is to run as small a rear sprocket as you can to maximize top speed but without giving away too much on the bottom end. The electronic governor minimizes governor droop.
Honda gx 160 quarter midget gear ratio. There is a balance between bottom end and top end speed. Product price is not filled in. If you can keep up in the tighter sections of the track and driver by the competition on the straights it will make overtaking much easier and make it that much harder for the competition to pass you back. Small engine timing belts are usually external and are subject to wear caused by dirt. There are many times where you will be fast in practice with (for example) an 11-80 sprocket combination but come race time you are pulled off the tight corners enough that you have to add a tooth or two so you can keep up with the competition. So in a situation like that you add a tooth (example in this is an 11-81) to minimize the amount of loss in the tighter sections with the hope that only adding one tooth still gives you an advantage on the straightaways.
This product cannot be purchased. The above can be reversed where you are fast through the tighter, slower parts of the track, can pull a gap but on the straights you lose too much ground.