the cylinder is a round void in the engine block where on most engines a cylinder liner is fitted you get two types of liner wet or dryin a dryengine block the liner dose not come in contact with the coolant and is a press fit wet liners are fitted by hand and coolant flowes around the linerliners are round construction for the nearly round piston to fitpiston rings fit into groves in the piston { langs } and this is what comes into contact with the liner to achive compression when the piston is moving up the cylinder or known as the bore
HumWell, bicycles are made of both of these metalsCr-Mo, of course is a steel alloyMost aluminum bikes are not pure aluminum; they are made of aluminum alloysMany purists beleive the best bikes are made of steel alloysSteel is a flexible material that can be made to provide a very comfortable rideSteel is also pretty inexpensiveSome of the most modern, high tech, steel alloys can be used to build bikes nearly as light as other materialsNeedless to say, a bike made of these very light steel alloys is not going to be inexpensiveAluminum is substantially lighter than steel, but less strongTo compensate for the lack of strength, aluminum tubes must be substantially larger than steel tubesAluminum is not flexible, thus aluminum bikes tend to provide a stiffer ride than a steel bikeAluminum is not a forgiving materialBuilding high quality aluminum frames requires much more welding skill than building a steel frameHowever, in the 30 or so years, bikes have been made from alumimun, the tricks have been very well masteredHope this helps.
