Front Rear Total %
17 45 2,6470 100,00%
17 46 2,7050 97,83%
17 47 2,7640 95,74%
16 45 2,8125 94,12%
16 46 2,8750 92,07%
16 47 2,9375 90,11%
15 45 3,0000 88,24%
15 46 3,0666 86,32%
15 47 3,1333 84,48%
You should avoid the 15/45 combo, it can cause bad chain/sprocket wear.
On slower tracks I use 15/44 or 15/46 and on faster tracks 16/44 or 16/46.
Now while I am at it, the size of your rear tire will also change your gearing:
Tire diameter (mm) %
190/50 635 100,00%
190/55 649 102,20%
190/60 655 103,15%
195/65 656 103,31%
200/55 656 103,31%
So if you change your rear tire from a 190/50 to a 190/55 and you change your gearing from 17/45 to 17/46 your total gearing change will be only 0.03%