VELLO bikes are delivered from the factory with Schwalbe Marathon 1.5 or Kojak 1.35 tyres (both E.T.R.T.O. 406). Tires up to 2.10 width, such as Crazy Bob or Big Apple can be mounted. Note: VELLO Bike frames also allow the installation of wheels for those who have an E.T.R.T.O. diameter of 451 (larger 20 inches).