No, that is why there are so many parts.
Part of a whole is any fraction there of. A half is a part of a whole and so on.
There are plenty of important parts on a bicycle. W/o any of these the bike wouldn't work. The main parts are wheels, frame and fork.
There is no standard collective noun for a group of motorists, in which case a noun suitable for the situation can be used; for example, a jam of motorists, a task force of motorists, a mob of motorists, etc.
Any fraction names a part of a whole. This includes 1/2, 4/5, -2/3, and so on.
1 mm on whole tire. If any part of tread is less then it should be replaced.
Can represent any number-even a fraction
Any bicycle part that makes contact with another part but needs to move to function must have friction reduced. The wheels bearings, steering head, pedal bearings in both the hub and pedal, and the chain links all are designed for minimum friction but they also need lubricant.
Strange question. you can go to a bicycle store, search ebay, craigslist or any other internet source of merchandise. Department stores carry(usually not so good) bikes.
Yes. It can mean the whole planet or any microcosm that is part of it.
Any part of the yam, whole or cut, as long as it has the skin (peel).
I don't, but someone certainly does. Any bicycle store who carry either Trek regular bikes or Trek stationary bikes should be able to get you in contact with someone who can do repairs.
One can purchase bicycle lights from a number of places. They can be purchased from Amazon, ebay, Revolights or Walmart. They should be easy to fit to any bicycle.