BD cam sizes

So I was recently looking at a cam comparison chart and I realized that Black Diamond cam sizes don't relate to their actually ideal range...what exactly is the point of that? And why would they use decimal numbers if they aren't going to relate to anything specifically. Can someone clear up the confusion?

While I don't know the historical reasons for BD making this specific decision, I think it should be noted that this happens in a lot of contexts. If you're buying lumber a 2x4 is not actually 2 inches by 4 inches. The "10" in a #10 screw is a gauge number and does not relate to the size. Back in the day, a "3 1/2 inch floppy disk" was actually a little larger than 3.5 inches. So I wouldn't worry about it too much. You can think of it as a nominal size like how a "1/2 inch pipe" is actually a good bit larger than 1/2 inch, or you can think of it like wire gauge where it's just a number assigned to the size as opposed to a number describing the size.

I guess if you are talking about their numbers #1 cam would be better called a #1.5, #2 could still be a #2, a #0.75 would be better off being a #1.25, #3 should be a #2.5 etc but I think it is easier to say I need a #1, #2, #3, etc but maybe they should have started a #0.5 as a #1 and gone up from there and left all the X4 / C3 as single numbers below that but whatever they are named what they are named.

The problem is though there isn't a single value besides maybe the middle point you could list for the size and at that point all of the would be a # point something and would be really annoying to name. Also I don't know how much a number matching to the size of the cam would really matter that much you aren't climbing with a ruler to see the size of every crack you are just going to eyeball it.

All fair responses. I guess I just always assumed that a #1 BD would be an ideal fit for a 1'' crack. Just wondered if anyone had an explanation of why they use the numbers they do.

Only the #2 matches up wit the center of the usable range. Maybe (probably not, but maybe) they started with the #2, since it is obviously the funnest size to climb, and worked their way up/down from there, leaving decent amounts of overlap. 

AlecBerg wrote:

All fair responses. I guess I just always assumed that a #1 BD would be an ideal fit for a 1'' crack. Just wondered if anyone had an explanation of why they use the numbers they do.

I am assuming what happened was we had some hippy rock climbers on LSD / smoking pot and they had a great idea for naming them and just put random numbers!

I'd guess that back in the day they started making camalots when #1 was the smallest viable size. When the smaller cams were developed, they had to go with fractional sizes. 

These may or may not support this notion: 

https://www.mountainproject.com/forum/topic/107018537/the-evolution-of-the-camalot

http://www.needlesports.com/content/nuts-story-clockwork-friends.aspx

AlecBerg wrote:

All fair responses. I guess I just always assumed that a #1 BD would be an ideal fit for a 1'' crack. Just wondered if anyone had an explanation of why they use the numbers they do.

Wait until you get to using DMM Dragon cams, or any cam by Metolius........

AlecBerg wrote:

All fair responses. I guess I just always assumed that a #1 BD would be an ideal fit for a 1'' crack. Just wondered if anyone had an explanation of why they use the numbers they do.

1" crack is to be protected with purple #0.5 C4.

Khoi wrote:

Wait until you get to using DMM Dragon cams, or any cam by Metolius........

Huh?   Metolius cam numbering makes far more sense than BD.   They are numbered 00, then 0-8.  Dragon cams are 00, then 0-6.  No the numbers don't have any relation to size,  but neither does BDs numbering. 

Totem is the only brand I know of that actually numbers their cams according to physical size.   0.5, 0.65, 0.8, 1.0, 1.25, 1.5, 1.8...  Personally,  I prefer more simple numbering schemes because they are easier to remember.   

That said,  I don't really find any numbering scheme to be very useful.   When I talk about placements with other people, I find it easiest to just convert from whatever brand I placed to the closest BD size and tell them the color.   Most climbers seem to be more familiar with the C4 colors than the numbering. 

The fact that cams are based on the logarithmic spiral means that consecutive cams physical sizes are not linear increments.  By that I mean if there is .25" difference between a #1 and #2 there definitely won't be a .25" diff between #5 and #6 (more like 1" difference).

I have never thought of any cam by any maker matching the number with size in inches.   I have always just thought of them as a number to differentiate between cams not tell you the exact size.   I have always just kind of eyeballed.   

cyclestupor wrote:

Huh?   Metolius cam numbering makes far more sense than BD.   They are numbered 00, then 0-8.  Dragon cams are 00, then 0-6.  No the numbers don't have any relation to size,  but neither does BDs numbering. 

It was in response to his apparent confusion regarding the #1 Camalot not fitting a 1" crack.  The #1 in Metolius is also a poor fit for a 1" crack, albeit in the opposite direction.

cyclestupor wrote:

Totem is the only brand I know of that actually numbers their cams according to physical size.   0.5, 0.65, 0.8, 1.0, 1.25, 1.5, 1.8...  Personally,  I prefer more simple numbering schemes because they are easier to remember.   

I think Aliens are like that as well, but most climbers just refer to them by their colour.

Khoi wrote:

I think Aliens are like that as well, but most climbers just refer to them by their colour.

Used to be that friends were numbered by the dead center of their range. To this day, I prefer a number 1 friend to a 0.5 camalot, but it's the gold friend (although even that color is wrong now) not the #1 friend.

Just wait til OP discovers Tricams.

This is ridiculous, most people know that majority of the planet works with the metric system. Inches are out you are climbing centimeter wide cracks boyz!! 

What's funny is Totems are from Basque Country in Spain but use inches. I prefer Totems numbers from a logical standpoint, but after using BD sizes for years and most people knowing BD sizes we tend to communicate in BD numbers.

I have a friend from Chile who is a contractor. I asked him if it was tough to make the conversion from metric to imperial/standard when he moved to the US and he said no, he actually prefers standard. Inches and feet are more convenient for the scales he works with. Which makes sense. e.g. 8 feet is better than 2.4 meters or 240 centimeters.