CYCLE CALCULATORS

CalculatorsStack and Reach Ratio Calculator

Stack and Reach Ratio Calculator

Stack over reach is the quickest way to see if a frame wants your hands low. The ratio ignores stem and spacers, so it compares frames rather than a finished bike.

Inputs

Units

Results

Stack / reach
1.49
Position code
3

The Result is indicative and educational. It does not constitute a design, a technical opinion or medical advice and does not replace calculations or verification by a person with the appropriate qualifications and authorisations. Before purchase, installation or use in practice – in particular in electrical installations – the Result should be verified by a qualified specialist. Details: Terms of Service, point 4.

How the number is made

Ratio = stack ÷ reach. Codes use a strict lower bound: below 1.35 is 1 (aggressive race), from 1.35 up to but not including 1.45 is 2 (race), from 1.45 up to but not including 1.55 is 3 (sporty all-rounder), and 1.55 or higher is 4 (upright endurance).

The 1.45 and 1.55 cutoffs follow the usual race / all-rounder / endurance split; 1.35 only separates the most aggressive race frames. The ratio shifts with frame size, so compare bikes in the same size. Spacers and stem angle move the bars without changing this frame ratio.

Frame versus finished bike

Add the stem calculator after this one. A −17° stem drops the bars; it does not rewrite the frame ratio printed on the geometry chart.

Related calculators

Questions

What is a normal endurance ratio?

Endurance frames usually sit at 1.55 or higher. From 1.45 to 1.55 is the sporty all-round middle, and mid-size race bikes mostly fall between about 1.40 and 1.45.

Can a long stem fix a short reach?

A little. Ten millimetres of stem is not fifteen millimetres of frame reach plus a taller stack.

Does exactly 1.45 still count as race?

No. 1.45 starts the sporty all-rounder band (code 3) and 1.55 starts upright endurance (code 4). A ratio of 1.449 is still race (code 2).

Example products

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