TRANSMISSION RANGE
To calculatorsFor 1x and 2x: the percentage range, the lightest and heaviest gear, the entire gear table, the steps between the stars of the cassette, doubles from the double, and checking if you will use this set in your ascent.
The recalculation goes by itself, there are no buttons. The link to the page saves your layout — you can throw it into the chat and argue about the stars in a substantive way.
The preset only fills this field — then straighten the teeth with your hands. Manufacturers change layouts from group to group, so if the preset is lying, you will see it and fix it.
Range = heaviest gear divided by lightest. 520% means that heavy gear is 5.2 times longer than light gear.
Ratio 0.77 · 21.6" · development 1.72m · 9.3 km/h
ratio 4.00 · 112.1" · development 8.95 m · 48.3 km/h
In the cell, the gear inches are large, the speed at the selected cadence and the development per pedal revolution are small.
The lightest transmission is highlighted in orange, and the heaviest is highlighted in black.
We count the step from a light star to a heavy one: how many percent does the gear increase when switching.
Gears that differ by less than 2.5% are considered the same: you can't feel such a difference with your feet.
Cross-over is considered only for 2x: 1x has nowhere to switch from the front.
We count by the lightest gear: speed at a given cadence, and from it — power on the rise.
Range — the ratio of the heaviest transmission to the lightest in percent. For 1x with a 10-52 cassette, this is 520%, for a highway 2x with 11-30, it is about 470%, but it is distributed much more densely there.
Gear inches — the diameter of the penny-farthing wheel with the same gear, the usual currency in conversations about the stars. The development is meters per turn of the pedals, and from it the speed is obtained at a given cadence.
Cassette Steps — how many percent does the transmission change when switching to a neighboring star. Up to 15% switching is almost imperceptible, 18-20% and above is a "hole": the cadence fails, you have to choose between "too hard" and "too easy".
Doubles — 2x has the same part of the gears on the big and small ring. You can't feel the difference of less than 2.5% with your feet, so the real transmissions of the double are always less than the product of the stars.
Cross-over — the star of the cassette, on which the small ring no longer makes the transmission easier than the lightest transmission of the large one. From here and higher on the cassette, it is more profitable to ride on a large ring: the chain goes more smoothly.
Checking the lift — the speed in the lightest gear at your cadence turns into power according to the classical resistance model: gravity, rolling (Crr 0.008) and air (CdA 0.36). W / kg is calculated by the weight of the system, so for pure watts per kilogram of rider the figure will be slightly higher.
We take the wheel circumference according to ETRTO as π × (rim diameter + two tire widths) — accuracy of the order of percent, this is enough to compare gears.