Why are 20inch car rims bigger than 20 inch bicycle rims?
Wednesday, November 24th, 2010 at
7:03 am
Are bicycle rims and car rims measured differently. The other day I had my 20 bmx bike next to my 16 inch truck rims and noticed that they were the same size. Even further I rode my bike across the street and compared them with my neighbors 20 inch he has on his car. The car rims were larger in diameter than my 20 inch bike rims. What is going on???
US $.99
20″ is measured inside the tires bead, which you don’t see when the tire is mounted. The bike has about a quarter inch holding the tire on the wheel, the truck about an inch and a quarter; doubled (top and bottom), that makes a big difference. The truck tire needs the extra support to stay on the wheel under load.
So don’t put your bike tires on the truck
Vehicle rims are measured without the tire on it, 20″ BMX wheels are measured with the tire included.