I read this book as an 18 year old, the summer I bought my first motorcycle and before I enlisted in the Marine Corps.
It's a good first step in a man's search for meaning- I say man's because the book has a distinctly male voice. It has much to say, and gives the reader much to digest, in spite of the above anonymous poster's valid critique noting the book's tendency to ramble.
I like the book because, while it faults much of our culture's values, it still tresures the good things it produces, be it western culture's dedication to reason and detail or that best of all good things, the motorcycle.
I never could figure out what kind of bike he had- was it a BSA? Triumph? He describes it as a twin-cylinder bike with about 28 horsepower, but never states the make, even though he mentions another character's BMW R60. That always bothered me, for some reason.
But this is a book to be read. I pity those who haven't read it, and mistrust those whose's lives were not, in some way, affected by it.