Bicycle
- Steamroller faktura, 56cm, 49/17T 170mm crank, wt ~9kg, frame 2.87kg (2.02+0.85kg, 4.46+1.87lbs) for 56cm uncut fork (2003-09).
- Crescent No 37, 55cm (2010-12)
- Leader 725, 55cm, 46/17T 165mm crank, wt ~9kg, alu frame (2013-05).
- Cinelli Vigorelli, 54cm, 48/17T 165mm crank, wt ~8.5kg, alu frame, carbon fork (2013-06).
- Vitus Venon CRX, 56cm, Ultegra Black R8000, hydralic disc (2018-09)
- Track Stand
Gear ratio
Pure gain ratio according to Sheldon Brown
Calculated as: wheel radius / crank length * front / rear T
Gearing and cadence
| Bike model | Gearing | Pure gain ratio |
|---|
| Surly Steamroller | 49/17T 700(680mm) wheel 170 crank | 5.76 |
| Leader 725 | 46/17T 700(680mm) wheel 165 crank | 5.57 |
| Cinelli Vigorelli | 48/17T 700(680mm) wheel 165 crank | 5.81 |
Cadence for a fixed is linear to the gearing.
(1056 / 1.609344 * rear * speed) / ( front * 26.28 * PI)
26.28 is constant for wheel 700x23/23-622
| Speed | Cadence |
|---|
| | 49/17T | 48/17T | 46/17T | 49/15T | 49/14T | 49/13T |
|---|
| 15 | 41 | 42 | 44 | 36 | 34 | 32 |
|---|
| 20 | 55 | 56 | 59 | 49 | 45 | 42 |
|---|
| 25 | 69 | 70 | 73 | 61 | 57 | 53 |
|---|
| 30 | 83 | 84 | 88 | 73 | 68 | 63 |
|---|
| 35 | 97 | 99 | 103 | 85 | 79 | 74 |
|---|
| 40 | 110 | 113 | 117 | 97 | 91 | 84 |
|---|
| 45 | 124 | 127 | 132 | 109 | 102 | 95 |
|---|
| 50 | 138 | 141 | 147 | 121 | 114 | 105 |
|---|
Recommended CT
Recommended CT length according to cyclecomponents.com
Length of leg in mm (B)
| racer | B x 0.883 - 180 = CT |
| MTB | B x 0.883 - 280 = CT |
B = 810mm
| racer | 715 - 180 = 535mm = 21" |
| MTB | 715 - 280 = 435mm = 17" |
33T - 18T comp
| 29" wheel. crank 175mm-180mm | 4.3 |
| 26" wheel. crank 175mm 4.3 with 33T front | = 16T back |
