Paul Warburton started an interesting thread, some time ago, about the usual weight of bows (which seems to run from about 125g to 148g), but I have not seen discussion of size or length. I have two bows that are around 26 inches long and this seems to be what I generally see. But one of my teachers uses a tiny bow - I would say around 18 inches and very thin and light, which he uses to wonderful effect. This got me thinking: why does the bow have to be so long and heavy? Is this some kind of unquestioned musical tradition? You might think that a bassist needs a long bow to play long tones but then you consider that we are taught to make the reversal of direction silent (so that you cannot tell when the direction changes), so what does it matter? What other reasons are there?