It depends on the size of sprocket being run, so if using 20 tooth sprocket, it would be equivalent of
38.0 lowest gear
29.4
26.0
22.8
20.1
17.6
15.5
13.7
12.0
10.6
9.3 highest gear
Worked out by dividing number of teeth on sprocket by ratio
Not quite. You need to count the teeth on the sprocket on the Alfine hub and divide by the ratio; for example a 20 tooth sprocket on ratio 1 (the lowest gear) gives this: 20/0.527=38 so a 20 tooth sprocket and gear 1 on that hub would be the equivalent of a 38 tooth sprocket on a cassette. Using the same 20 tooth sprocket on the next gear you get the equivalent of 29.4 tooth sprocket on a cassette. Obviously there is no such thing as .4 of a tooth so I would round to the nearest whole number. Based on that, you would get the following cassette: 9-11-12-14-16-18-20-23-26-29-38Thanks Andy so much.
Using the 2 lowest gear as example, 38-29.4 = 8.6, I suppose shld be either 8 or 9 teeth, is that correct?
Not quite. You need to count the teeth on the sprocket on the Alfine hub and divide by the ratio; for example a 20 tooth sprocket on ratio 1 (the lowest gear) gives this: 20/0.527=38 so a 20 tooth sprocket and gear 1 on that hub would be the equivalent of a 38 tooth sprocket on a cassette. Using the same 20 tooth sprocket on the next gear you get the equivalent of 29.4 tooth sprocket on a cassette. Obviously there is no such thing as .4 of a tooth so I would round to the nearest whole number. Based on that, you would get the following cassette: 9-11-12-14-16-18-20-23-26-29-38
Its just an example. The Alfine has options for 18, 20, 21, 22, or 23T sprockets