Motorcycle Front/Rear Size Comparator

The Motorcycle Front-Rear Size Comparator works by computing the diameter and width of the front and rear tires and showing the gap and width ratio. Front and rear tires on a motorcycle differ by design.

1. Enter the front size, for example 120/70ZR17 (600 mm).
2. Enter the rear size, for example 190/50ZR17 (622 mm).
3. Read the width gap: +70 mm.
4. Read the width ratio: 1.58.

The Motorcycle Front-Rear Size Comparator formula is Width Ratio = Rear Width ÷ Front Width, with diameters from the standard formula.

Worked example: 110/80R19 front (659 mm) with 150/70R17 rear (642 mm) gives a width ratio of 1.36.

The Motorcycle Front-Rear Size Comparator conversion table compares 8 front and rear pairs. Width ratios run from 1.15 (cruiser) to 1.67 (sport and adventure).

Sport bikes run the widest rear-to-front ratios. A wider rear puts more rubber on the road at full lean.

The Motorcycle Front-Rear Size Comparator is a tool that compares a motorcycle's front and rear tire specifications. The front tire steers and the rear tire drives, so each has a different size.

Changing either tire changes the bike's pitch and steering. The comparator shows how a new pair sits against the factory pair.

The Motorcycle Front-Rear Size Comparator has 4 uses: pair replacements, rear upgrades, geometry checks and project bikes.

• Replace pairs: Compare a new front-rear set.
• Upgrade the rear: Check a wider rear against the front.
• Check geometry: See the pitch change.
• Build projects: Match wheels from another model.