I currently have my motor in parts and am about to put it back together. I have seen that they make different front sprockets. I am sure the benefits are quicker power delivery but is it truly advantageous? I am sure it costs a few MPG.

If it is a good idea which would be the best use; 13T, 14t, or ? I am not a big rider but I am a solid 180 lbs.

Depends on what kind of riding you do, and what characteristics you wouldnt mind losing. Use the search button, several good threads:
http://gstwins.com/gsboard/index.php?action=search2

See if you can find a 5T ~ that oughta get you mucho acceleration

pretty sure I read somewhere that anything below 14T will be damaging or need a different rear sprocket or chain as well.

I forget which.  (too much going on and lost all my bookmarks rebooting my computer)

15T is probably the best overall if your going to change from stock.
14T, even quicker accel but even more of a loss of high end speeds then 15T.

Blatantly ripped off from Sledge...

Search: "Chordal action chains"

By the time you take 2 teeth off the front sprocket, you're usually just eliminating 6th gear. We ran some charts and found that in some cases, lowering the gearing resulted in worse acceleration.

None...


Just MHO


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it only really changes thing if the you lower it slightly, otherwise like was previously said, you're just replacing your 6th gear with an even lower 1st gear. That's perfectly fine if you spend a lot of time in stop and go riding and want the extra torque leaving redlights and in traffic, but you'll definitely feel it when you hit a wide open noise and keep trying to shift to your non existant 6th gear every time you hit 40mph.

I've never bought the 'it makes it easier to pass cars on the highway without dropping down a gear or two'. If that's what you want just ride in 5th gear on the highway, because that's all you're doing with the gear change. Then you just lose the ability to cruise comfortably.