# Question on Shimano Alfine, 11 speed

#### novetan

##### Über Member
I just purchase a folding bike Tern Verge using Shimano Alfine, 11 spd. That's all the spec tells me. I tried to google but only to be told its a 400% gearing ratio, something like that which I don't understand. Anyone knows how's the spacing of the teeth?

Tks

#### Andy_R

##### Hard of hearing..I said Herd of Herring..oh FFS..
Here you go Alfine ratios

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#### novetan

##### Über Member
Tks Andy.

How does the various gear ratio translate to no. of teeth? I don't understand gear ratio. Perhaps you may want to give an example for gear ratio 1 listed as 0.527 means what?

Tks so much.

#### Andy_R

##### Hard of hearing..I said Herd of Herring..oh FFS..
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

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#### novetan

##### Über Member
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

Thanks 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?

#### Andy_R

##### Hard of hearing..I said Herd of Herring..oh FFS..
Thanks 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

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#### novetan

##### Über Member
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

Tks again Andy.

Where do you derive 20 tooth sprocket? Is it native (or default) for Shimano Alfine 11 spd or just an example?

Tks again

#### Andy_R

##### Hard of hearing..I said Herd of Herring..oh FFS..
Its just an example. The Alfine has options for 18, 20, 21, 22, or 23T sprockets

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#### novetan

##### Über Member
Its just an example. The Alfine has options for 18, 20, 21, 22, or 23T sprockets

I see. Tks Andy.

Anyone here can offer advise what is theno. of teeth for the sprockets of Shimano Alfine 11 spd?

#### Andy_R

##### Hard of hearing..I said Herd of Herring..oh FFS..
Looks like 18 teeth on the sprocket. Use Sheldons gear calculator here