BD cam sizes


Original Post
AlecBerg · · Unknown Hometown · Joined Nov 2014 · Points: 5

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?

ViperScale · · Unknown Hometown · Joined Dec 2013 · Points: 230

I am confused because they do match up.

A number 1 C4 cam is listed as [1] 30.2-52.1 mm (1.19-2.05 in). This is the size range that you can place the gear in. If you look on the chart it shows red C4 line between around 1.25 inch to 2 inch... now I guess you are talking about ideal range vs max / min range which is what they list.

Ronald B · · Los Angeles, CA · Joined Oct 2016 · Points: 0

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.

John Wilder · · Las Vegas, NV · Joined Feb 2004 · Points: 1,530

I think he's referring to the part where everything at the #1 and below doesn't really correspond in inches. (i.e. a 1" cam is the purple 0.5 camalot, not the #1).

To the OP- it's just the system that BD uses, there's probably some reasoning behind it from when the original cams were built way back when, but at the end of the day, it doesnt really matter. Most people I know don't even refer to the # of the cam anyway- we mostly discuss by color. 

ViperScale · · Unknown Hometown · Joined Dec 2013 · Points: 230

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.

AlecBerg · · Unknown Hometown · Joined Nov 2014 · Points: 5

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.

Zach Parsons · · Tacoma, WA · Joined Aug 2013 · Points: 100

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. 

ViperScale · · Unknown Hometown · Joined Dec 2013 · Points: 230
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!

mike again · · Berkeley, CA · Joined Dec 2015 · Points: 40

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

Rob T · · Unknown Hometown · Joined Jun 2006 · Points: 10

Original camalots were 1, 2, 3. Just numbered for easier designation. After a number of years they released the camalot Jrs, benign smaller than 1 they could use fractions or negative numbers. They went w .75 and .5 (not sure how they came up w those fractions). Later .1-.4 were added as micros and 3.5 and 4.5 were added to address earlier gaps(later retroed to integers w the introduction of C4s)

TLDR holdover from earlier, arbitrary standard, like RR gauges. 

Khoi · · Vancouver, BC · Joined Oct 2009 · Points: 45
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........

Pavel Burov · · Russia · Joined May 2013 · Points: 50
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.

cyclestupor · · Woodland Park, Colorado · Joined Mar 2015 · Points: 93
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. 

cyclestupor · · Woodland Park, Colorado · Joined Mar 2015 · Points: 93

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).

Kevin Mokracek · · Burbank · Joined Apr 2012 · Points: 200

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.   

Khoi · · Vancouver, BC · Joined Oct 2009 · Points: 45
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.

Khoi · · Vancouver, BC · Joined Oct 2009 · Points: 45
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.

Petsfed · · Laramie, WY · Joined Mar 2002 · Points: 925
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.

Gunkiemike · · Unknown Hometown · Joined Jul 2009 · Points: 2,740

Just wait til OP discovers Tricams.

Guideline #1: Don't be a jerk.

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