27.5" (650B) Bike Tire vs 700x25c Bike Tire

The 27.5" (650B) Bike Tire and 700x25c Bike Tire are most easily told apart by their overall size. On height, the 27.5" (650B) Bike Tire measures 700.0 mm against the 700x25c Bike Tire's 670.0 mm — about 30.0 mm more. On width, the 27.5" (650B) Bike Tire measures 700.0 mm against the 700x25c Bike Tire's 670.0 mm — about 30.0 mm more. On thickness, the 27.5" (650B) Bike Tire measures 55.0 mm against the 700x25c Bike Tire's 25.0 mm — about 30.0 mm more.

The 27.5" (650B) Bike Tire is the heavier of the two at 800 g, compared with 300 g for the 700x25c Bike Tire. That is a 500 g difference (167%). The weight gap is modest and rarely the headline difference between them.