Rim Width to Tire Width Match Calculator

WORKSHOP FITMENT TOOL

Rim Width to Tire Width Match Calculator

Verify tire-to-rim width safety, ETRTO 2023 vs legacy standards, estimated mounted tire inflation width, and the aerodynamic Rule of 105.

1. Interface Parameters

Internal Rim Width 21.0 mm

Internal channel distance between rim beads / flanges.

Outer Rim Width (for Aero Rule of 105) 28.0 mm

External rim track measurement at its widest point.

Nominal Tire Width 28.0 mm

Stamped manufacturer tire dimension.

Rim Flange Profile

ETRTO Standard

Total System Weight 80 kg (176 lbs)

Rider + Bicycle + Gear combined.

2. Technical Compatibility

✓

IDEAL MATCH

Excellent tire-to-rim casing match within official safety guidelines.

Rim-Tire Interface Profile

Est. Mounted Width

28.8 mm

+0.8mm actual expansion

Rule of 105 (Aero)

97%

Rim is 97% of tire width

Rec. Pressure Range

65 – 75 PSI

4.5 – 5.2 bar

Rim-to-Tire Ratio

1.33 : 1

Ideal: 1.4:1 – 2.2:1

Fitment & Technical Guidance

ETRTO Status: Compliant with ETRTO standards.
Aerodynamic Fit: Good transition between tire and rim wall.

Calculations strictly follow 2023 ETRTO and ISO 5775 guidelines. Maximum pressure on hookless rims must never exceed 73.5 PSI (5.0 bar) regardless of tire sidewall ratings.