13tooth is for more low end. Depends on type of riding you will be doing. The 14t, wont hardly hold a idle on its own, and the 13t has no problem. It will almost will idle up my trailor! For $20 or under it's well worth the swap! And if you dont like change it back, it's like just a few min task.thanks. is it worth it for the extra acceleration?
I love my 15t7mph is the average top speed loss. I tried the 13 tooth yesterday for the first time. It made 1st and 2nd gear completely worthless. hit the rev in second gear in less then half a second. made the bike feel slow. I really hated it soooo much. Most on here seam to love it, but its just not for me. Switched back to the 14 after an hour ride, and it was night and day. now I'm curious to try a 15.