Inspirational 31+ 25Mm Road Bike Tires
Inspirational 31+ 25Mm Road Bike Tires. Until recently, most road bikes only had clearance for 25mm tyres, so unless you've got a relatively new bike, it's sadly not a given you'll be able to upgrade to a 28mm tyre or larger. Tpi refers to 'threads per inch' and indicates how many individual threads of woven nylon or cotton cross. Road tires typically come in 23mm, 25mm, and 28mm widths. A standard road wheel size is 700c with the more common options of 23, 25 or 28mm widths.