The sidewall width lies. 321 public measurements prove it — and we turn them into pressure.
The width the manufacturer prints on the sidewall is almost never the real mounted width. This dataset compiles the real vs nominal width of 321 road and gravel tires published by BicycleRollingResistance (159 road, 162 gravel), corrects it for internal rim width, and turns it into the empirical core of the BikeLab PSI Calculator. On that public data we build the constant-deflection model (Berto 15% criterion), validated by cross-reference against SILCA and Rene Herse. The width census is BRR's; the model, the calibration and the uncertainty are ours.
What the census proves, not opinion:
Representative extract of the model validation over the census. The ±PSI band is the 90% confidence interval (Latin Hypercube):
| Case | Configuration | Mean [p5–p95] | Band ±PSI |
|---|---|---|---|
| 1 | 83 kg · 28 mm · road · rim 21 | 73 [63–86] | ±11.7 |
| 2 | 95 kg · 28 mm · road · rim 21 | 84 [72–100] | ±13.8 |
| 3 | 75 kg · 32 mm · road · tube · rim 19 | 63 [54–73] | ±9.2 |
| 4 | 85 kg · 40 mm · gravel · rim 24 | 38 [35–41] | ±3.2 |
| 5 | 100 kg · 45 mm · gravel · rim 25 | 39 [36–41] | ±2.5 |
| 6 | 70 kg · 25 mm · road · rim 21 | 71 [59–85] | ±12.8 |
// Sample. The width census is public (BicycleRollingResistance). What we deliver under agreement is what we add: the correction tables by model/rim, the calibrated coefficients and the sampling code (see access).
Module_03 // Reserved MethodThe methodology is public and reproducible —it is described in the white paper with its DOI— and the width census comes from the public database of BicycleRollingResistance. What we reserve is what is ours and not BRR's: the correction tables by model/rim, the calibrated coefficients and the sampling code. We reveal what we found and how; that derived set is shared under agreement, so that whoever uses it cites it and does not merely absorb it.
Module_04 // Record (cite this)The corrections, calibration, validation and model are our own; the underlying width census is public data from BicycleRollingResistance, used with attribution. The model parameters allow independent validation with additional field data. Provisional by design.
Need the complete dataset, a specific cut or a validation against your catalog? It is delivered under agreement from the Independent Laboratory · carlos.ravello@zoovettravel.com
// Acknowledgment: this work would not exist without the public census and measurement methodology of BicycleRollingResistance (Jarno Bierman). Thank you for publishing open, rigorous data.
© 2026 BikeLab Studio. Content under CC BY 4.0: you may copy, translate and publish it, even for commercial purposes. Citation is mandatory. Without attribution, the license terminates automatically (CC BY 4.0, §6.a) and the use becomes copyright infringement: we request the removal of the content and its deindexing. · Design and ownership: Carlos Ravello Joo