Cycle gear chart : 790mm wheel diameter |
This chart shows the gears for different chainrings and sprockets on a cycle where the propelled wheel has a diameter of 790mm.
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 | 69" | 76" | 83" | 90" | 97" | 104" | 111" | 117" | 124" | 131" | 138" | 145" | 152" | 159" | 166" | 173" | 180" | 187" | 194" | 200" | 207" | 221" | 235" |
| 10 | 62" | 68" | 75" | 81" | 87" | 93" | 100" | 106" | 112" | 118" | 124" | 131" | 137" | 143" | 149" | 156" | 162" | 168" | 174" | 180" | 187" | 199" | 211" | |
| 11 | 57" | 62" | 68" | 74" | 79" | 85" | 90" | 96" | 102" | 107" | 113" | 119" | 124" | 130" | 136" | 141" | 147" | 153" | 158" | 164" | 170" | 181" | 192" | |
| 12 | 52" | 57" | 62" | 67" | 73" | 78" | 83" | 88" | 93" | 98" | 104" | 109" | 114" | 119" | 124" | 130" | 135" | 140" | 145" | 150" | 156" | 166" | 176" | |
| 13 | 48" | 53" | 57" | 62" | 67" | 72" | 77" | 81" | 86" | 91" | 96" | 100" | 105" | 110" | 115" | 120" | 124" | 129" | 134" | 139" | 144" | 153" | 163" | |
| 14 | 44" | 49" | 53" | 58" | 62" | 67" | 71" | 76" | 80" | 84" | 89" | 93" | 98" | 102" | 107" | 111" | 116" | 120" | 124" | 129" | 133" | 142" | 151" | |
| 15 | 41" | 46" | 50" | 54" | 58" | 62" | 66" | 70" | 75" | 79" | 83" | 87" | 91" | 95" | 100" | 104" | 108" | 112" | 116" | 120" | 124" | 133" | 141" | |
| 16 | 39" | 43" | 47" | 51" | 54" | 58" | 62" | 66" | 70" | 74" | 78" | 82" | 86" | 89" | 93" | 97" | 101" | 105" | 109" | 113" | 117" | 124" | 132" | |
| 17 | 37" | 40" | 44" | 48" | 51" | 55" | 59" | 62" | 66" | 70" | 73" | 77" | 81" | 84" | 88" | 91" | 95" | 99" | 102" | 106" | 110" | 117" | 124" | |
| 18 | 35" | 38" | 41" | 45" | 48" | 52" | 55" | 59" | 62" | 66" | 69" | 73" | 76" | 79" | 83" | 86" | 90" | 93" | 97" | 100" | 104" | 111" | 117" | |
| 19 | 33" | 36" | 39" | 43" | 46" | 49" | 52" | 56" | 59" | 62" | 65" | 69" | 72" | 75" | 79" | 82" | 85" | 88" | 92" | 95" | 98" | 105" | 111" | |
| 20 | 31" | 34" | 37" | 40" | 44" | 47" | 50" | 53" | 56" | 59" | 62" | 65" | 68" | 72" | 75" | 78" | 81" | 84" | 87" | 90" | 93" | 100" | 106" | |
| 21 | 30" | 33" | 36" | 39" | 41" | 44" | 47" | 50" | 53" | 56" | 59" | 62" | 65" | 68" | 71" | 74" | 77" | 80" | 83" | 86" | 89" | 95" | 101" | |
| 22 | 28" | 31" | 34" | 37" | 40" | 42" | 45" | 48" | 51" | 54" | 57" | 59" | 62" | 65" | 68" | 71" | 74" | 76" | 79" | 82" | 85" | 90" | 96" | |
| 23 | 27" | 30" | 32" | 35" | 38" | 41" | 43" | 46" | 49" | 51" | 54" | 57" | 60" | 62" | 65" | 68" | 70" | 73" | 76" | 78" | 81" | 87" | 92" | |
| 24 | 26" | 29" | 31" | 34" | 36" | 39" | 41" | 44" | 47" | 49" | 52" | 54" | 57" | 60" | 62" | 65" | 67" | 70" | 73" | 75" | 78" | 83" | 88" | |
| 25 | 25" | 27" | 30" | 32" | 35" | 37" | 40" | 42" | 45" | 47" | 50" | 52" | 55" | 57" | 60" | 62" | 65" | 67" | 70" | 72" | 75" | 80" | 85" | |
| 26 | 24" | 26" | 29" | 31" | 33" | 36" | 38" | 41" | 43" | 45" | 48" | 50" | 53" | 55" | 57" | 60" | 62" | 65" | 67" | 69" | 72" | 77" | 81" | |
| 28 | 22" | 24" | 27" | 29" | 31" | 33" | 36" | 38" | 40" | 42" | 44" | 47" | 49" | 51" | 53" | 56" | 58" | 60" | 62" | 64" | 67" | 71" | 76" | |
| 30 | 21" | 23" | 25" | 27" | 29" | 31" | 33" | 35" | 37" | 39" | 41" | 44" | 46" | 48" | 50" | 52" | 54" | 56" | 58" | 60" | 62" | 66" | 70" | |
| 32 | 19" | 21" | 23" | 25" | 27" | 29" | 31" | 33" | 35" | 37" | 39" | 41" | 43" | 45" | 47" | 49" | 51" | 52" | 54" | 56" | 58" | 62" | 66" | |
| 34 | 18" | 20" | 22" | 24" | 26" | 27" | 29" | 31" | 33" | 35" | 37" | 38" | 40" | 42" | 44" | 46" | 48" | 49" | 51" | 53" | 55" | 59" | 62" | |
| 36 | 17" | 19" | 21" | 22" | 24" | 26" | 28" | 29" | 31" | 33" | 35" | 36" | 38" | 40" | 41" | 43" | 45" | 47" | 48" | 50" | 52" | 55" | 59" | |
| 38 | 16" | 18" | 20" | 21" | 23" | 25" | 26" | 28" | 29" | 31" | 33" | 34" | 36" | 38" | 39" | 41" | 43" | 44" | 46" | 47" | 49" | 52" | 56" | |
| 40 | 16" | 17" | 19" | 20" | 22" | 23" | 25" | 26" | 28" | 30" | 31" | 33" | 34" | 36" | 37" | 39" | 40" | 42" | 44" | 45" | 47" | 50" | 53" | |
For derailleur gears:
- Choose chainrings and sprockets that give your preferred top and bottom gears and a sensible spread inbetween.
- Choose similar percentage jumps between your rear sprockets, not equal numbers of teeth. (For example, a shift of one tooth from 12t to 13t feels the same as two teeth from 24t to 26t - they both lower the gear by 8%.)
For hub gears:
- Choose a chainring and sprocket that give your preferred middle gear. Multiply this by the high and low ratios for your particular hub in order to find your top and bottom gears.
Recommendations:
- Many cyclists like their 'normal' gear to be around 65 inches, with an overall range from 30 to 95 inches.
- Gears under 11 inches are too low for bicycles as it's difficult to balance at such slow speeds. But they can be used on tricycles and quadricycles, where balancing isn't a problem.
- Gears over 100 inches are too high for general use on bicycles.
- Choose the correct length cranks and never try to achieve a higher gear by using longer ones as this could damage your knees.
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© Chris Bell |
