www.koga.com login

Gearing - Derailleur - Internal hub gear - 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 meters), 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 meters), 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 2.18 m (a 1:1 gear ratio). 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.

Spacing between gears

It’s best if there are even gaps between the gears. Unfortunately this is not always the case. The ideal gap, in percentage, is between the 7% and 14%. If it is less, then when you change gears you will hardly notice the difference as you ride along, and if it is more, that that has a negative effect on the ride. The advantage of having many gears is that the gaps between the gears are smaller, so that as conditions change you can always find the ideal gear ratio for your preferred pedalling frequency.

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

* For tyre size 700x35C (37-622)

Deore, Deore LX & Deore XT (44/32/22-11/32)

1 2 3 4 5 6 7 8 9
Gearing Cassette 32 28 24 21 18 16 14 12 11
1 22 Metres of development 1,50 1,72 2,00 2,29 2,67 3,00 3,43 4,01 4,37
2 32 2,19 2,50 2,91 3,33 3,89 4,37 5,00 5,83 6,36
3 44 3,00 3,43 4,01 4,58 5,34 6,01 6,87 8,01 8,74
Gear range 582%

Rohloff Speedhub 500/14 (42-16)

1 2 3 4 5 6 7 8 9 10 11 12 13 14
Gear Sprocket 57,3 50,6 44,4 39,1 34,5 30,3 26,7 25,5 20,7 18,2 16 14,1 12,4 10,9
1 42 Metres of development 1,60 1,81 2,07 2,35 2,66 3,03 3,44 3,91 4,44 5,05 5,74 6,51 7,41 8,42
Gear range 526% 0,279 0,316 0,360 0,409 0,464 0,528 0,600 0,682 0,774 0,881 1,000 1,135 1,292 1,467

Rohloff Speedhub 500/14 / Gates belt drive (50-19)

1 2 3 4 5 6 7 8 9 10 11 12 13 14
Gear Sprocket 68,1 60,1 52,8 46,5 40,9 36 31,7 27,9 24,5 21,6 19 16,7 14,7 13
1 50 Metres of development 1,60 1,82 2,07 2,35 2,67 3,04 3,45 3,92 4,45 5,07 5,75 6,53 7,43 8,44
Gear range 526% 0,279 0,316 0,360 0,409 0,464 0,528 0,600 0,682 0,774 0,881 1,000 1,135 1,292 1,467

Shimano Alfine 11-speed (38-20)

1 2 3 4 5 6 7 8 9 10 11
Gear Sprocket 38 29,4 26 22,8 20 17,6 15,5 13,7 12 10,6 9,3
1 38 Metres of development 2,19 2,83 3,20 3,65 4,13 4,71 5,36 6,07 6,92 7,84 8,94
Gear range 409% 0,527 0,681 0,770 0,878 0,995 1,134 1,292 1,462 1,667 1,888 2,153

Shimano Alfine 8-speed (42-19)

1 2 3 4 5 6 7 8
Gear Sprocket 36,1 29,5 25,4 22,3 19 15,5 13,4 11,8
1 42 Metres of development 2,55 3,11 3,61 4,11 4,83 5,91 6,86 7,80
Gear range 306% 0,527 0,644 0,748 0,851 1,000 1,223 1,419 1,615