MashON useful tools
Estimate front and rear bicycle tire pressure in PSI or bar, with total weight, measured tire widths, temperature and equipment limits.
Switching units converts your entered values. All results use the same formulas as MashON for iPhone.
Your inputs stay on this device. This tool does not upload or save them.
This is a starting estimate, not a certified safe pressure. Verify tire/rim compatibility and manufacturer limits. Hookless requires approved combinations; 5 bar is a ceiling, not a target. Tubes do not make an incompatible tire safe.
The road model uses Dave Adams’ fit to Berto’s 15% tire-drop chart: PSI = 153.6 × wheel load (lb) ÷ measured width (mm)1.5785 − 7.1685. The chart covers 20–37 mm widths and 30–70 kg wheel loads. Other inputs extrapolate beyond it. This is not a SILCA, SRAM, or Wolf Tooth algorithm.
MTB, fat bikes, and gravel tires wider than 37 mm use MashON’s experimental width-squared scaling from the 37 mm reference. It is not validated for impacts or soft terrain. Temperature compensation uses absolute pressure and Kelvin, assuming constant volume.
Surface, casing, tubes, speed, impacts and riding style are not modeled. Rocks and potholes can require more support. Do not lower pressure below equipment limits for comfort or grip. Track, snow, ice, sand and downhill setups need specialist advice. Use a reliable gauge.
MashON is available for iPhone and Apple Watch.
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