I am not doubting your hands and eyes, I just know that they don't always feel and see what we think they do. Apparently black is slimming, (maybe that's why it's usually concert dress?) and I'm curious just how much of a difference there is. On wood bows, most measurements have a pretty tight tolerance to "standard" numbers. My theoretical appreciation of math is pretty lacking, but I would suggest that there is likely a tolerance of about +/- 5-10% on any measurement. The smaller ones such as pearl slide width and frog height for example could have very small tenths of millimetre deviations, where bigger ones like overall length or hair length could have larger ones measured in millimetres or even centimetres, but still within the +/- 5-10% range. Does that make sense?
When it comes to diameter of the stick, typically we measure behind the head, in front of the frog, and at the end of the stick and use those as our key measurements. While the graduations (how quickly the behind the head dimension tapers out to the finished dimension) will change from stick to stick, most makers keep both ends fairly consistent from bow to bow. If it is a particularly light/heavy or dense stick, they might change by 0.5mm or so. If the bow is made from a different species of wood like Snakewood, sometimes those numbers need to be tweaked because of the different material, which gets nicely into carbon fibre.
Carbon Fibre isn't wood. For that reason, it doesn't have the same general characteristics that the woods we use to make bows have. It doesn't need to follow the wood "rules" to achieve the same strength and weight because it isn't wood, but we still want it to look, feel, and act like a bow. For that reason, and because I really don't know too much about how carbon fibre bows are engineered, it's tough to draw conclusions about how they compare to wooden bows based on things like measurements because a correlation or lack there of doesn't necessarily mean causation.
What does that mean in relation to the diameter of the stick? Snakewood bows tend to be thinner than Pernambuco because Snakewood is particularly heavy and strong and one of the usual characteristics of Snakewood is that it is very responsive. Is that because of a characteristic of the material, or a characteristic of the dimension? I haven't had an opportunity to play and measure enough Snakewood/non-Snakewood bows by the same maker to see if that is the case or if it is any of the countless other variables that are responsible.
Working on bows has given me a better appreciation of what makes a bow feel a certain way to the player. Weight and balance greatly influences how agile a bow feels, and is a big factor when considering fatigue. The winding and grip contribute to the weight and balance, but also change the diameter of a French bow where you hold onto it. A whale bone winding is significantly wider than silk, with silver/gold being even narrower, although there are a few different gauges of metal used. Likewise if the leather is particularly firm/cushy or if it has a thicker/thinner profile (which can be adjusted by putting something on top of the winding underneath the leather) that changes how closed/open the hand is around the stick which can greatly influence comfort. Rubber tubing is a dramatic example in the direction of opening up the hand, where players that don't use a thumb leather is the opposite. The thumb projection is another as some of them are particularly tall and angular while others are shorter and rounder. If your bow grip involves pressure on the thumb projection and it is not a shape that is agreeable to you, it can lead to pain. Quite a few players notice these things mostly sub-consciously particularly if they are different than what they are used to when they are shopping for a new bow, but don't usually give them much thought afterwards.
Hair and rosin have been discussed at length here but they can greatly influence how much work you have to put into the bow to get it to do what you want it to. Besides all of the black vs. white vs. "other" hair debates or hard vs. soft rosin debates old hair does not perform the same as new hair, and a lot of players feel old rosin, particularly the really soft varieties, do not perform as well as a new cake. If one has black, the other has white, and your rosin choices vary, you are comparing apples to oranges with hair as well as the bow materials. I still think it would be a great idea for a large shop that handles a lot of rehairs to have a collection of carbon fibre bows with each of their different hair options in them to offer a side by side comparison, but that's another topic for another day.
Hopefully that's as clear as mud?
