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This chart shows the gears for different chainrings and sprockets on a cycle where the propelled wheel has a diameter of 690mm.
The number of Gear inches shown for each chainring/sprocket combination indicates how easy or hard it will be to push that particular gear. Small values are easy to push and high values help you go faster. Use the chart to compare different combinations and to select those appropriate for your kind of cycling.
| chainring |
||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |
20 | 22 | 24 | 26 | 28 | 30 | 32 | 34 | 36 | 38 | 40 | 42 | 44 | 46 | 48 | 50 | 52 | 54 | 56 | 58 | 60 | 64 | 68 | |
| rear cog |
9 | 60" | 66" | 72" | 78" | 85" | 91" | 97" | 103" | 109" | 115" | 121" | 127" | 133" | 139" | 145" | 151" | 157" | 163" | 169" | 175" | 181" | 193" | 205" |
| 10 | 54" | 60" | 65" | 71" | 76" | 81" | 87" | 92" | 98" | 103" | 109" | 114" | 120" | 125" | 130" | 136" | 141" | 147" | 152" | 158" | 163" | 174" | 185" | |
| 11 | 49" | 54" | 59" | 64" | 69" | 74" | 79" | 84" | 89" | 94" | 99" | 104" | 109" | 114" | 119" | 123" | 128" | 133" | 138" | 143" | 148" | 158" | 168" | |
| 12 | 45" | 50" | 54" | 59" | 63" | 68" | 72" | 77" | 81" | 86" | 91" | 95" | 100" | 104" | 109" | 113" | 118" | 122" | 127" | 131" | 136" | 145" | 154" | |
| 13 | 42" | 46" | 50" | 54" | 59" | 63" | 67" | 71" | 75" | 79" | 84" | 88" | 92" | 96" | 100" | 104" | 109" | 113" | 117" | 121" | 125" | 134" | 142" | |
| 14 | 39" | 43" | 47" | 50" | 54" | 58" | 62" | 66" | 70" | 74" | 78" | 81" | 85" | 89" | 93" | 97" | 101" | 105" | 109" | 113" | 116" | 124" | 132" | |
| 15 | 36" | 40" | 43" | 47" | 51" | 54" | 58" | 62" | 65" | 69" | 72" | 76" | 80" | 83" | 87" | 91" | 94" | 98" | 101" | 105" | 109" | 116" | 123" | |
| 16 | 34" | 37" | 41" | 44" | 48" | 51" | 54" | 58" | 61" | 65" | 68" | 71" | 75" | 78" | 81" | 85" | 88" | 92" | 95" | 98" | 102" | 109" | 115" | |
| 17 | 32" | 35" | 38" | 42" | 45" | 48" | 51" | 54" | 58" | 61" | 64" | 67" | 70" | 74" | 77" | 80" | 83" | 86" | 89" | 93" | 96" | 102" | 109" | |
| 18 | 30" | 33" | 36" | 39" | 42" | 45" | 48" | 51" | 54" | 57" | 60" | 63" | 66" | 69" | 72" | 75" | 78" | 81" | 85" | 88" | 91" | 97" | 103" | |
| 19 | 29" | 31" | 34" | 37" | 40" | 43" | 46" | 49" | 51" | 54" | 57" | 60" | 63" | 66" | 69" | 71" | 74" | 77" | 80" | 83" | 86" | 92" | 97" | |
| 20 | 27" | 30" | 33" | 35" | 38" | 41" | 43" | 46" | 49" | 52" | 54" | 57" | 60" | 62" | 65" | 68" | 71" | 73" | 76" | 79" | 81" | 87" | 92" | |
| 21 | 26" | 28" | 31" | 34" | 36" | 39" | 41" | 44" | 47" | 49" | 52" | 54" | 57" | 60" | 62" | 65" | 67" | 70" | 72" | 75" | 78" | 83" | 88" | |
| 22 | 25" | 27" | 30" | 32" | 35" | 37" | 40" | 42" | 44" | 47" | 49" | 52" | 54" | 57" | 59" | 62" | 64" | 67" | 69" | 72" | 74" | 79" | 84" | |
| 23 | 24" | 26" | 28" | 31" | 33" | 35" | 38" | 40" | 43" | 45" | 47" | 50" | 52" | 54" | 57" | 59" | 61" | 64" | 66" | 69" | 71" | 76" | 80" | |
| 24 | 23" | 25" | 27" | 29" | 32" | 34" | 36" | 38" | 41" | 43" | 45" | 48" | 50" | 52" | 54" | 57" | 59" | 61" | 63" | 66" | 68" | 72" | 77" | |
| 25 | 22" | 24" | 26" | 28" | 30" | 33" | 35" | 37" | 39" | 41" | 43" | 46" | 48" | 50" | 52" | 54" | 57" | 59" | 61" | 63" | 65" | 70" | 74" | |
| 26 | 21" | 23" | 25" | 27" | 29" | 31" | 33" | 36" | 38" | 40" | 42" | 44" | 46" | 48" | 50" | 52" | 54" | 56" | 59" | 61" | 63" | 67" | 71" | |
| 28 | 19" | 21" | 23" | 25" | 27" | 29" | 31" | 33" | 35" | 37" | 39" | 41" | 43" | 45" | 47" | 49" | 50" | 52" | 54" | 56" | 58" | 62" | 66" | |
| 30 | 18" | 20" | 22" | 24" | 25" | 27" | 29" | 31" | 33" | 34" | 36" | 38" | 40" | 42" | 43" | 45" | 47" | 49" | 51" | 53" | 54" | 58" | 62" | |
| 32 | 17" | 19" | 20" | 22" | 24" | 25" | 27" | 29" | 31" | 32" | 34" | 36" | 37" | 39" | 41" | 42" | 44" | 46" | 48" | 49" | 51" | 54" | 58" | |
| 34 | 16" | 18" | 19" | 21" | 22" | 24" | 26" | 27" | 29" | 30" | 32" | 34" | 35" | 37" | 38" | 40" | 42" | 43" | 45" | 46" | 48" | 51" | 54" | |
| 36 | 15" | 17" | 18" | 20" | 21" | 23" | 24" | 26" | 27" | 29" | 30" | 32" | 33" | 35" | 36" | 38" | 39" | 41" | 42" | 44" | 45" | 48" | 51" | |
| 38 | 14" | 16" | 17" | 19" | 20" | 21" | 23" | 24" | 26" | 27" | 29" | 30" | 31" | 33" | 34" | 36" | 37" | 39" | 40" | 41" | 43" | 46" | 49" | |
| 40 | 14" | 15" | 16" | 18" | 19" | 20" | 22" | 23" | 24" | 26" | 27" | 29" | 30" | 31" | 33" | 34" | 35" | 37" | 38" | 39" | 41" | 43" | 46" | |
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