Just a word of warning - if you have a lectric xp2, the 20x4 tire will rub against your chain (see photo). I bought a Vee Tire Fat Bike Tube 20x4.0 Light 40mm Schrader Valve from BicycleBuys.com - $50/each. The tire seems nice, but the x4 vs. the x3 causes the tire to bulge out & contact the...