2006-08-15 01:54:38 · 4 answers · asked by Jithu 1 in Science & Mathematics ➔ Engineering
To lighten up the car. The drum is basically a cylinder.The strength of a cylinder depends only on the material it is made of and its outer surface. The same principle is behind why our bones are hollow.
2006-08-15 02:00:42 · answer #1 · answered by dennis_d_wurm 4 · 0⤊ 0⤋
Weight and temperature. The grooves and holes can be place strategically to reduce the weight and yet retain structural strength. Remember that the amount of horsepower needed to move (or stop) a vehicle is directly related to the weight of the vehicle. Looking two pounds per wheel can add up to 8lbs of weight loss. Shaving weight makes the fuel usage go up and has really become a necessity with today's small engines.
Also, the grooves and holes allow for the disapation of heat. To stop a vehicle, brakes are employed and uses friction between the brake shoes and the drums. Friction creates heat and this heat needs to be dispursed. The holes and grooves promote faster cooling.
Hope this answered your question!
2006-08-15 02:02:46 · answer #2 · answered by wrkey 5 · 0⤊ 0⤋
To allow the air to pass through and reduce the heat on the wheel drum.
2006-08-15 02:03:59 · answer #3 · answered by A.Ganapathy India 7 · 0⤊ 0⤋
Less weight & Cooling...
2006-08-15 04:20:39 · answer #4 · answered by Anonymous · 0⤊ 0⤋