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Gearing - Double - Compact - Triple - Gear range - Gear ratio - Development

General information gearing systems

A measure of bicycle gearing is ‘development’. This is the distance which a bicycle travels when the pedals are rotated a complete turn (360 degrees). If it is small (a low number of metres), then you go less far, but the pedals are easier to turn: this is recommended for steep hills or strong headwinds. Should you be using a high gear ratio (development is a higher number of metres), then it’s harder to turn the pedals, but you go faster when you do – for example downhill or with a tail wind. The overall gear range is the difference between the lowest and highest gears.

The following notes bring together some advice which should be considered when selecting which gear system which will be right for you.

Lowest ratio, first gear

If you often ride in hilly or mountainous terrain, you will often use your lowest gear. Your lowest gear should offer a development of no more than 4,5 m. It is recommended that you have even lower gears than this available.

Highest ratio, top gear

If you mostly ride in a sporty manner and at high speeds, you will often need to change into your highest gear. That means that in top gear you have a large ’development’, so that for every turn of the pedals you cover as great a distance as possible.

Below you will find a summary of the gear ratio ranges offered by the various transmission systems (double, triple and compact) in Koga Signature, together with an overview of the particular gear systems on offer.

* For tyre size 700x23C (23-622)

Dura Ace Double with 11-21T

1 2 3 4 5 6 7 8 9 10
Gearing Cassette 21 19 18 17 16 15 14 13 12 11
1 39 Metres of development 3,90 4,31 4,54 4,81 5,11 5,45 5,84 6,29 6,82 7,44
2 53 5,29 5,85 6,18 6,54 6,95 7,41 7,94 8,55 9,26 10,11
Gear range 259%

Dura Ace Double with 11-25T

1 2 3 4 5 6 7 8 9 10
Gearing Cassette 25 23 21 19 17 15 14 13 12 11
1 39 Metres of development 3,27 3,56 3,90 4,31 4,81 5,45 5,84 6,29 6,82 7,44
2 53 4,45 4,83 5,29 5,85 6,54 7,41 7,94 8,55 9,26 10,11
Gear range 309%

Dura Ace Compact with 11-21T

1 2 3 4 5 6 7 8 9 10
Gearing Cassette 21 19 18 17 16 15 14 13 12 11
1 34 Metres of development 3,40 3,75 3,96 4,20 4,46 4,75 5,09 5,49 5,94 6,48
2 50 4,99 5,52 5,83 6,17 6,55 6,99 7,49 8,07 8,74 9,53
Gear range 281%

Dura Ace Compact with 11-25T

1 2 3 4 5 6 7 8 9 10
Gearing Cassette 25 23 21 19 17 15 14 13 12 11
1 34 Metres of development 2,85 3,10 3,40 3,75 4,20 4,75 5,09 5,49 5,94 6,48
2 50 4,20 4,56 4,99 5,52 6,17 6,99 7,49 8,07 8,74 9,53
Gear range 334%

Ultegra Double with 12-25T

1 2 3 4 5 6 7 8 9 10
Gearing Cassette 25 23 21 19 17 16 15 14 13 12
1 39 Metres of development 3,27 3,56 3,90 4,31 4,81 5,11 5,45 5,84 6,29 6,82
2 53 4,45 4,83 5,29 5,85 6,54 6,95 7,41 7,94 8,55 9,26
Gear range 283%

Ultegra/105 Triple with 12-25T

1 2 3 4 5 6 7 8 9 10
Gearing Cassette 25 23 21 19 17 16 15 14 13 12
1 30 Metres of development 2,52 2,74 3,00 3,31 3,70 3,93 4,20 4,49 4,84 5,24
2 39 3,27 3,56 3,90 4,31 4,81 5,11 5,45 5,84 6,29 6,82
3 52 4,36 4,74 5,19 5,74 6,42 6,82 7,27 7,79 8,39 9,09
Gear range 361%

Ultegra/105 Compact with 12-25T

1 2 3 4 5 6 7 8 9 10
Gearing Cassette 25 23 21 19 17 16 15 14 13 12
1 34 Metres of development 2,85 3,10 3,40 3,75 4,20 4,46 4,75 5,09 5,49 5,94
2 50 4,20 4,56 4,99 5,52 6,17 6,55 6,99 7,49 8,07 8,74
Gear range 306%