Bicycles are enormous quantity of human machinery, lubrication structure type sliding friction and rolling friction, a little friction and cable friction, fluid and boundary lubrication, oil lubrication and grease lubrication. The key parts of the bicycle is kinetic friction axis and the front and rear axle, is the use of ball bearings, with No. 2 calcium-based grease lubrication. Have the ball and bead groove and each time the door cleaning maintenance clean, smooth evenly to the bead tank No. 2 calcium-based grease, filled with smooth surface along the axis around rounded complete and uniform particles, the same size of private balls (beads ), then Shanghao door, do not allow dust contamination. But on the bike is a special case, in order to simplify the device without grease nipple, only additional lubricant to improve lubrication. Second gear wheel and chain lubrication, there is mixed friction sliding friction and rolling friction, and most in boundary lubrication, friction and thus more demanding conditions, must use better adhesion and lubrication oil lubrication, in particular most are open in case of a dirty job, to chain and gear plate badly worn, so we should always (quarterly or six months) cleaned according to the situation and replace it with new oil, most with a viscosity of greater use oil (40 ℃ viscosity 10-20mm2 / s), but in general and also with the same three-axis plus oil, this is more convenient. Edit this paragraph using normal normal riding riding is not need to use any technology, but it is the maintenance of the bicycle, the most important and the most basic one, before riding, to check the condition of the bike, it is it is important, is often forgotten, so before the ride, remember to do the following checks: check the riding position size: If you do not ride their own special car, remember before you ride the seat is adjusted to the proper height . Tightness check various parts of screws: Check the front and rear wheels and seat quick release lever are tight, and check whether the handlebars are fixed, the other screws are loose situation. Check the tires: Check the tire pressure is adequate, it is insufficient to hit the proper pressure, tire check whether there are cracks in the wall, if the tread has been cut too shallow, if necessary, shall replace the tire. Check the brakes: pull the front and rear brake test, check whether the brakes can actually braking. Check the car before the wrist: front brakes stopped the vehicle back and forth, if any felt shaking gap, showing the vehicle in front wrist to be re-adjusted. Check the transmission: first try after the start and after each shift before shift change, can smoothly change to stall speed, whether there will be a strange strange noise.