Stack to reach

Stack divided by reach tells you how steeply the line from the bottom bracket to the head tube rises. The steeper it is, the higher and closer the bars sit. A typical race bike for 175 cm has 1.41, an endurance bike 1.49.

Race versus endurance

One typical frame each for the same body height, averaged over the bikes in the catalogue. The endurance bike is taller and a little shorter, so the line rises more steeply.

165 cm: race 1.38, endurance 1.44. The endurance bike is 16 mm taller and 5 mm shorter. 170 cm: race 1.40, endurance 1.46. The endurance bike is 17 mm taller and 6 mm shorter. 175 cm: race 1.41, endurance 1.49. The endurance bike is 19 mm taller and 7 mm shorter. 180 cm: race 1.43, endurance 1.51. The endurance bike is 20 mm taller and 7 mm shorter. 185 cm: race 1.45, endurance 1.53. The endurance bike is 19 mm taller and 7 mm shorter. 190 cm: race 1.46, endurance 1.54. The endurance bike is 19 mm taller and 8 mm shorter.

The kinds on one map

Each line is the average of one kind, from small to large frames, with rings at 170, 180 and 190 cm body height. The shaded area shows how widely the bikes spread, and the faint dots are the single sizes. Along each dashed line the ratio is the same.

Race Endurance Gravel

Stack and reach are listed in the geometry table of your bike.

Stack divided by reach of a typical bike, by body height
	165 cm	175 cm	185 cm
Race	1.38	1.41	1.45
Endurance	1.44	1.49	1.53
Gravel	1.46	1.48	1.50

Compare at the same size only

The ratio grows with size, because large frames mostly get taller and barely longer. A race bike for 190 cm has 1.46, an endurance bike for 165 cm only 1.44: the large race bike has the number of an endurance bike. So only compare bikes for the same body height or with a similar reach.

That is why the frame map does not sort by the ratio but by how much taller a frame is at the front than a race frame of the same length. To the frame map

What else sets the three kinds apart, on three frames in size 58: Race, endurance or gravel?

Where the numbers come from

Stack and reach of 35 models from the manufacturers' geometry tables, sorted by what the manufacturer calls the bike. Most manufacturers give a body height for every size; for the lines, each model's sizes are joined over body height and averaged across the models at each body height. The shaded area reaches one standard deviation up and down.

The frames above: stack and reach from the line; seat angle, head angle, fork, chain stay and bottom bracket like an average bike of the same kind.