/ WC Friends - weight

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Deadeye - on 19 Jun 2017
I was thinking of cutting down the weight of my rack.

Am I misreading it or has the change from Forged to technical to helium not actually saved any weight?

For example for a Friend 2.5
- Forged 120g
- Tech 122g
- Helium 117g

Or Friend 1
- Forged 89g
- Technical 90g
- Helium 90g

Eh?
MischaHY - on 19 Jun 2017
In reply to Deadeye:
If you're looking for weight savings take a look at the ultralight camalots. They're threaded with dyneema instead of cable, and the difference is insane.
Post edited at 10:55
David Barlow - on 19 Jun 2017

First, Heliums are dead: they failed in the market. They were a failed attempt to replace old friends. Wild County have now created new double-axle friends instead.

Second, the weight of the equivalents normal set (1-4) old friend (0.5-4 C4, 1-6 dragon, etc) are the following (prepare to be surprised...). These numbers are from the manufacturers' websites.

782gm Ultraliight C4
999gm C4
991gm new friends
1009gm dragon
976gm old friends

I couldn't believe the old friend number, so weighed mine, and the numbers are correct, even though you need an extra old friend compared to the re-balanced range of other cams: double axles weigh more. Apart from ultralight C4s of course.

Note that the Ultralight C4s are not always as strong as the other cams: 10-12 KN vs. 12-14KN. This may not matter to you.
It's unclear whether the ultralight C4s will have the longevity of the other cams.
Also the C4s do not have extendable slings, so you'd need to take more quickdraws, which will add back the weight the ultralights save. That may or may not matter.
C4s are much more expensive than the alternatives, and Ultralights even more.

Personally the new friend looks great: extensible slings, nice thumb loop, British, and currently a great price (deals of 3 for £130).
Post edited at 12:34
gethin_allen on 19 Jun 2017
In reply to Deadeye:

I didn't think the change from forged to flexi stems was supposed to be about weight, more about their utility in shallow and odd shaped cracks without requiring a 'gunks tie off
beardy mike - on 19 Jun 2017
In reply to Deadeye:

Yes the forged friends were light - the cable and swage in the Helium were heavy for sure - 12g for the copper swage along and of course the cable is stainless steel rathr than Aluminium. Lobes in like for like material you will never save masses of weight on. And yes the new friends have two axles although we saved weight by making them hollow so there's not so much difference. If you want light and really robust, take a look at the Metolius Ultralight powercams and master cams. Although some won't like the ladder design.
Deadeye - on 19 Jun 2017
In reply to gethin_allen:

> I didn't think the change from forged to flexi stems was supposed to be about weight, more about their utility in shallow and odd shaped cracks without requiring a 'gunks tie off

Sure - but if you think about how much weight has come off carabiners over the same period, it's surprising (to me at least) that we've stood still in cams.
Timmd on 19 Jun 2017
In reply to David Barlow:
I never really understood why Friends needed updating or replacing, I liked the fact that there were more units for the same range in crack sizes, it seemed sensible to me because you can only place each friend once. I guess if sales go down compared to competitors something needs to be done.

I know there's an 'arms race' when it comes to weight, but things like lighter snapgates and screwgates throughout a rack, and sensible runner placement to lessen rope drag and other odds and sods, probably make more difference than needing an extra friend it seems to me.

I liked that the stem could rotate around the axle without disturbing the individual cams too, that isolation or simplicity of things appealed to me.

It was always better a few years ago. ;-)
Post edited at 14:11
Timmd on 19 Jun 2017
In reply to Deadeye:
> Sure - but if you think about how much weight has come off carabiners over the same period, it's surprising (to me at least) that we've stood still in cams.

I guess it comes down to progress in manufacturing, the I beam 'biner body was a big step forward on from after the forging process which only put metal where it was needed, which was progress on from alu bar stock simply being bent into shape, which was a huge step up from steel. There used to be a steel snapgate in the climbing cupboard in my childhood home and it weighed loads.

With friends/camming devices, I guess there's only so much which can be done with cables and axles and lobes etc before things become too weak for what's required, and the steps have been smaller because of where things started out from in terms of lightness.
Post edited at 20:43
beardy mike - on 19 Jun 2017
In reply to Deadeye:

You've not acknowledged that an aluminium stem is by its nature much lighter than a steel cable and copper swage and a stainless steel termination. That is where your weight is coming from. There is only so much you can do to optimise weight when you are geometrically constrained by what you are trying to achieve The weight loss in carabiners has largely come from removing gate weight - 2 steel components and an aluminium one and replacing them with a single stainless wire. If you look at new solid gate biners they are not that dramatically different to old solidgate biners. Also we have decided that smaller biners are acceptable - if for example you took a phantom and laid it overthe top of an old DMM Eclipse you'd find the eclipse is about 30% larger. So it's not real wonder they are lighter...
Deadeye - on 20 Jun 2017
In reply to beardy mike:

> You've not acknowledged that an aluminium stem is by its nature much lighter than a steel cable and copper swage and a stainless steel termination. That is where your weight is coming from. There is only so much you can do to optimise weight when you are geometrically constrained by what you are trying to achieve The weight loss in carabiners has largely come from removing gate weight - 2 steel components and an aluminium one and replacing them with a single stainless wire. If you look at new solid gate biners they are not that dramatically different to old solidgate biners. Also we have decided that smaller biners are acceptable - if for example you took a phantom and laid it overthe top of an old DMM Eclipse you'd find the eclipse is about 30% larger. So it's not real wonder they are lighter...

Thanks for this. My observation wasn't intended as a criticism! However just about all my other kit has substantially reduced in weight:
- trading my old Joe Brown helmet for a nice new one was a huge gain
- ditto my old alpine rucksac for a modern version
- my ropes are now 60m for less weight than my old 45m
- ditto my carabiners (yes I get the size thing)
- my slings are now 6mm dyneema not 1" nylon
- my B2 boots are half the wieght of my old Meindls
- my hollofil jacket and fleece are both lighter than my woolly jumper
- my ice axes are a fraction of the weight of my Chacal and Barracuda
- even my rockboots have become shoes...

As far as I can see, only my cams and my belay device (stitch plate) have stayed the same.

gethin_allen on 20 Jun 2017
In reply to Deadeye:

> Sure - but if you think about how much weight has come off carabiners over the same period, it's surprising (to me at least) that we've stood still in cams.

I don't understand your point really. Why does something getting better have to equate to it getting lighter?

If you really want lighter cams and don't want to cough up for the new ultralight C4s (which you haven't acknowledged in any of your posts) just go back to using old forged friends, I'm sure you could find a few on E-bay.

As it is you have a far safer and more versatile product that weighs about the same as the old stuff did. I wouldn't call that standing still.
Dell on 20 Jun 2017
In reply to Deadeye:

I do not know why people beat up on the Heliums, they were/are a perfectly good cam for the vast majority of climbers. Proper thumb loop, extendable sling, can happily take a bashing. They were priced slightly lower than the competition, the savings add up when you are buying a set, which also makes it easier to swallow when one gets dropped in the sea.
I wonder sometimes if Wild Country were right to replace them, instead of just marketing them as a more reasonably priced everyday cam.
Deadeye - on 20 Jun 2017
In reply to gethin_allen:

> I don't understand your point really. Why does something getting better have to equate to it getting lighter?

<sigh> It was a gentle musing, not a personal attack on the innovation capability of cam designers. The musing breaks down into the list I gave a couple of posts up from here.

> If you really want lighter cams and don't want to cough up for the new ultralight C4s (which you haven't acknowledged in any of your posts) just go back to using old forged friends, I'm sure you could find a few on E-bay.

Gosh. I wasn't attacking you; don't be defensive! I have gone through my sack and trded in most things for lighter/better stuff over the years. I was surprised that the same trend hadn't seemed to find it's way to cams. It's great that there is now a recent line offering 20% weight saving; but they're prohibitively expensive. I'll just stay with what i have for now.

> As it is you have a far safer and more versatile product that weighs about the same as the old stuff did. I wouldn't call that standing still.

That's an interesting point. Most of the products I've listed have been *both* better and lighter. Mike has explained why the innovation was harder in cams (although Camalot do now seem to have done so). Not sure the products are "far safer" if well placed. Shallow horizontal placements I guess. Although flexible friends came out a long time ago now. So not sure i agree really - but I started the thread to express surprise, not to pick a fight!
MischaHY - on 20 Jun 2017
In reply to Dell:

I'm very happily still using my heliums that I got for an absolute bargain price (£25 each for 2/2.5/3) - but I think Wild Country needed to step their game up.

With the new friends, the superlight wires, the upcoming revo and now the new shoes they've just announced, I think that's happened. Good to see!
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Robin Woodward - on 20 Jun 2017
In reply to David Barlow:

Just to add in a comparison for Totems. In the range where the Totem cam overlaps the C4 (0.3 - 2), the Totems weigh 638 g and the C4 667 g. Approximately the same stats but with C4's having the edge - Totems having slightly less strength (~1 kN) and range (~1 mm in smaller sizes, up to 2 in the largest). Obviously totems have some other advantages.
David Barlow - on 20 Jun 2017
In reply to Deadeye:

I'd resisted sharing my spreadsheet, but here it is... https://drive.google.com/open?id=1Fk8BPSkkuJmViEOEDWoTUdK6L1nRiG6ipffMyrc9igo
beardy mike - on 20 Jun 2017
In reply to Deadeye:

Again, this has to do with optimisation. It's a great testament to Ray Jardine who was a nasa engineer that what he produced was more or less optimised. But lets deal with your examples:

Helmets - a complete lack of knowledge about what was required of a helmet lead them to be over engineered. Added to this they were glass fibre - essentially what has happened with helmets is they've removed the glass, made the shell out of what remains, the PE and then made that as light as possible whilst retaining the impact resistance as set by UIAA standards. I.e. there is no excess material

Old Alpine rucksacks used heavy duty cordura, heavy frames, thick padding etc. and they lasted until they fell apart at the seams through overuse. These days the fabircs are paper thin don't last particularly long, the foams used are much more cut away than they used to be.

Ropes - Again size - this has absolutely nothing to do with materials as the material is within a gnats chuff the same stuff as it has been for decades. Sure manufacturing methids have improved by PA6 is still PA6 and weighs the same. But ropes have gotten thinner and thinner, partly because of the better manufacturing methods, and partly because a lower margin of safety has been deemed acceptable.

Already explained the carabiners.

6mm slings are far less abrasion resistant than 1" nylon. There is a huge margin of safety with a 1" tape which again has been deemed unnecessary. But you will find that if you test residual strength of a 6mm tape after a few years it will be massively reduced - maybe by up tp 50%! Not so with a nylon tape.

B2 boots - well they've changed steel shanks for plastic and leather for plastic so purely lighter materials on that one. You'll find an all leather boot is still a little lighter than they used to be but no THAT much.

Wooly jumpers... can't really say much to that one...

Ice axe penetration has ben massively improved through design and thus it allows them to be lighter. But there again I remember when MT Vertiges came out they were 550g which would be about the same time as the Barracuda and chacal. Admittedly it was like punching ice for the day, but there aren't many axes which are much lighter than that these days - maybe the Grivel North machines and axes of their ilk. There I'd say the shift change has come from improved performance.

Rockboots - well who the hell needed a boot anyway?

Back to the cams though - I'd have to look up precise numbers but the gist is that on smaller cams the stem on a flexible unit consitutes something like 70% of the total weight of the unit. So taking a WC Helium as an example, I can tell you that the sling weighs about 11g, the copper ferrule that joins the two pieces of steel together weighs 12g, the stainless termnation at the other end is 12g, the 7x7 stainless cable for the main stem is about 25 g, the thumbloop cable about 15. All that adds up. And to meet strength requirements you cant go down in size. The cables are rated at I think it's 14-15kN. You might be able to exchange materials but what to? Titanium is hugely expensive so that would get passed on, you might drop a third of the cable weight and termination weight, but then you combine Ti and Stainless or worse alu you get Galvanic corrosion. The lobes them self are more or less optimised already. Swap to magnesium and you take a huge hit on tensile strength so you need to put more material into it. And it's massively expensive. So the only way to change your lot whilst retaining a flexible stem is to get radical and start removing steel and replacing them for chemically inert, high strength composite materials. But even then you'd need to be careful. Carbon for example is one of the most galvanically corrosive materials about so you need to design the material interfaces very carefully. I could go on but my point is that Cams have actually been designed pretty optimally from the start!

Deadeye - on 20 Jun 2017
In reply to beardy mike:

Indeed!

So perhaps the truly surprising thing is not so much the true innovation curve (which is driven by materials, manufacturing methods, user expectations, etc) but the perceived one - which is driven by marketing. I was genuinely surprised that "Helium" friends were in reality so identical to the flexibles they replaced.

And whilst I understand the point that there are constraints on the components that produce finite limits, the ultralights do show that some innovaiton is still possible...
Coel Hellier - on 20 Jun 2017
In reply to beardy mike:

Isn't there a case for a single-axle version of the new Friends, or would they simply not sell?

I have some of the new Friends, which I really like, but my main impression is that I quickly run out of them on a pitch! That being the downside of double-axle philosophy, of fewer, heavier units with a bigger range. So I usually carry my Helium Friends as well.
Deadeye - on 20 Jun 2017
In reply to Coel Hellier:

I don't own either the new or the helium; are there other differences between "single axle version of new" and heliums/original flexibles then?
Jim C - on 20 Jun 2017
In reply to Deadeye:

Of course cutting down the rack is one option, as is spending mega bucks on lighter gear, but only after we are honest to ourselves and think would it be cheaper, safer ( healthier) just to shed those spare pounds most of us have;)

beardy mike - on 20 Jun 2017
In reply to Coel Hellier:

Yes - there is definitely a case for them. But it's not up to me to decide what they sell! I put forward a case for a range of Alpine friends - single axle with a wider spread between the cams so that the percentage overlap was smaller so you had fewer cams covering the same range but less weight than the double axle units and so thatall of them would overlap one another at the middle of their range. Apparently there is not the market for that. I guess at the end of the day you have to be market driven. Personally I still think there is a market for superlight single axles cams, as light as the Metolius power cams, single stem, slightly less strength but more density of sizes as you say. But double axles are definitely the market leader in terms of sales so there you go...
beardy mike - on 20 Jun 2017
In reply to Deadeye:

That's a pretty major difference right there! Single verses double axle in the larger sizes (i.e. above the purple 0.5) really does improve the amount of range you have, although it is somewhat overstated IMO as the lobes of a single axle cam are able to rotate further than a double axle which are strictly limited to 90deg. On a single axle cam it's more like 112degs so if you optimise the triggerwire location, you only lose a few percent. Of course older models don't do this so range is substantially less.

The upside of single axles is they are certainly more robust in that forces created by the lobes counteract one another as the lobes are on one axle whereas the double axle lobes need extra support to be OK. Added to this single axle placements do not sift in their placements if you move the stem about.

Conversely the double axle cam has built in camstops and the lobes are unable to snag when you're pulling them out and rotate around to get stuck in the crack. Doesn't happen often but when it does it's a pain...

Deadeye - on 20 Jun 2017
In reply to Jim C:

> Of course cutting down the rack is one option, as is spending mega bucks on lighter gear, but only after we are honest to ourselves and think would it be cheaper, safer ( healthier) just to shed those spare pounds most of us have;)

Ha! Have a like.

In term sof £ per gram saved the biggest winner was my ice axes, then helmet, then rucksac.
Timmd on 20 Jun 2017
In reply to Coel Hellier:
> Isn't there a case for a single-axle version of the new Friends, or would they simply not sell?

> I have some of the new Friends, which I really like, but my main impression is that I quickly run out of them on a pitch! That being the downside of double-axle philosophy, of fewer, heavier units with a bigger range. So I usually carry my Helium Friends as well.

Exactly. I guess it means a friend grabbed in a pinch is more likely to fit, but fewer cams for the same range means less placements.
Post edited at 21:54
beardy mike - on 20 Jun 2017
In reply to Timmd:
Of course the trouble when deciding a range is that you are somewhat constrained by what other people have done. People are a bit numbers obssessed. If I had my way, I'd have made the overlap from one cam to the next greater so that each double axle mid range was centred around the middle of the old friend sizes, that way you'd have more cams in the range with greater range. But when you've got the two main competitors having basically the same sizes in their ranges, the commerical argument is that people will want to buy ones to fit in with what they have...
Timmd on 20 Jun 2017
In reply to beardy mike:
That's interesting. I was getting the impression that trends are happening in camming devices, with Dragons and Friends and Black Diamond's ones all seeming similar.

I guess it's quite a bold step to bring out a range which doesn't slot neatly in with the competing ranges of camming devices, but put a lot of marketing into explaining why that range is the one to switch over to.

Post edited at 22:46
beardy mike - on 20 Jun 2017
In reply to Timmd:

Well yeah, and when it doesn't work... and I do remember in days of yore when you'd buy a cam here and there from different manufacturers and you'd end up with sodding great big gaps. When we did the new friends we went to great pains to make sure they are absolutely consistent and tweaked everything up and down here and there so they all run into one another perfectly. It's not a massive difference I'll grant you but at least it's been thought about!
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Timmd on 20 Jun 2017
In reply to beardy mike:
It was more of a thought off the top of my head than a serious thought. I think I can remember there being gaps between cams, not so long ago really.

Edit: Seems to be as I get older, a particular length of time can feel more recent.
Post edited at 23:50
Jim C - on 22 Jun 2017
In reply to Deadeye:

> Ha! Have a like.
> In term sof £ per gram saved the biggest winner was my ice axes, then helmet, then rucksac.

It's a serious point though, I was struggling quite a bit with my new touring bike (when fully loaded with all my 'essentials' ) I looked long and hard at the cost of changing the gearing to give me a bit extra help on the big hills ( it was pretty expensive)

Instead I just put loads of weight on my bike and went out for training runs , and at the same cut down my intake of calories, I lost a stone, over a reasonably safe period, and I now sail up the big hills because I'm lighter and fitter( and it did not cost me a penny)

Spending lots of cash, or sacrificing safety is not always the only answer(unless you are already super fit , with no spare flab, I was neither)
Toerag - on 22 Jun 2017
In reply to David Barlow:

> I'd resisted sharing my spreadsheet, but here it is...

nice. Can you add the head widths to it, I think that's an often-overlooked important factor, especially in the smaller sizes.
Casa Alfredino - on 22 Jun 2017
In reply to Toerag:

Remember in the larger sizes you actually want a wide head for stability! Narrow in smalls and wide in big
David Barlow - on 22 Jun 2017
In reply to Toerag:

That's a good suggestion, I'll try to do it soon.
Maybe I should add the price, then the price/gram which will be entertaining for the Ultralight C4.
David Barlow - on 22 Jun 2017
In reply to David Barlow:

I've added head widths and prices, and a cheeky £/gm cell. I can't find any info on the dragon #7 and #8 beyond its maximum range, but I've added anyway.
Coel Hellier - on 22 Jun 2017
In reply to beardy mike:

Thought I'd ask: the new Friends don't go very small, and there is surely scope for at least one smaller size. Any comment?
beardy mike - on 23 Jun 2017
In reply to Coel Hellier:

They just showed the 0.4 at outdoor. Below that there is no point as the gain you get is marginal compared to the loss in lateral strength. Ie when you place badly in a sub optimal placement and load the lobes sideways they are easyish to snap. There is no such problem with single axle systems.
Rock to Fakey - on 11 Jul 2017
In reply to Deadeye:
Wanting to start putting a set of cams together... The Metolius ultralight mastercams are only around £50 each at some vendors, and the lightest of the lot. Single axles.

I'd prefer to buy WC or DMM, but with there's a big difference in weight with these Metolius ones. I'm not sure if there are more cam sizes to complete the range. One downside as already mentioned is the lack of extendable slings, hope they will change that sometime!
Post edited at 12:32
gethin_allen on 11 Jul 2017
In reply to Rock to Fakey:

They look pretty good, the only bad thing I've ever heard said about metolius cams is that the axles rust a bit if you don't look after them, which isn't really a problem as you should look after your gear anyway.
purplemonkeyelephant - on 11 Jul 2017
In reply to Jim C:

Yeah but in fairness it's easier and more fun to eat some cake and then buy some sexy carbon fibre.
Rock to Fakey - on 11 Jul 2017
In reply to gethin_allen:
My previous post is incorrect, Metolius ultralight mastercams are not the lightest!

Actually still not that much in it... Metolius ultralight mastercams.. Size 3 to size 8 covers 18.5 - 71.5mm (this range stops here at size 8, but i didn't include 1 2 +3 as below the sizes in David Barlows spreadsheets range ) at 565g.

WC New friends 506g similar range coverage from sizes 0.5 - 2.

The Metolius set to cover this compared range would be £30 cheaper, but that's not so important.

But... On a range of 19 - 65mm the C4's save about 120g over the others in the spreadsheet; hard to compare with Metolius's as the sizings different + including the 8 covers another 6 or 7mm, but with it in BD Ultralight c4's are 180 or so grams lighter than these Metolius ultralights!

But C4's also lack extendable slings....!
Post edited at 13:27
Rock to Fakey - on 11 Jul 2017
In reply to Deadeye:
Perhaps knock 65g (half the size 8's weight) off to show Mets covering up to 65mm range, then the Mets covering 20 - 65mm = 498g, but BD Ultralight c4's that range are still 108g lighter!
(@ 390g for 0.5, 0.75, 1 + 2)

5 pieces of gear with the Mets though, perhaps would be more versatile, 1 extra placement, sizes 3, 4, 5, 6, + 7 (+ half the weight of the 8 for fair comparison to 65mm width, as 7 only goes to 57.5mm) = about 498g.

WC Old Tech friends also had 5 pieces covering that range, but at 580 g, so BD have sort of saved a massive 190g, until you add extendable slings, which would bring it up about another 50g in total for the set of 5 if directly fitted (60cm 10mm dynema sling =24g, do they only extend to 30cm on those with extending slings?).
Post edited at 14:00
jezb1 - on 11 Jul 2017
In reply to Rock to Fakey:

Personally would avoid metolius if you do any sea cliff stuff. They corrode and seize very easily compared to other cams which is a shame.
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DubyaJamesDubya - on 11 Jul 2017
In reply to Jim C:

> Of course cutting down the rack is one option, as is spending mega bucks on lighter gear, but only after we are honest to ourselves and think would it be cheaper, safer ( healthier) just to shed those spare pounds most of us have;)

And when you have the rack will be a bigger proportion of the weight you have to pull up with your fingers...
Rock to Fakey - on 11 Jul 2017
In reply to DubyaJamesDubya:

I know, but i can't shed much at 10.5 stone, could perhaps drop to 10 ok ! It's been a while that i was near.
beardy mike - on 11 Jul 2017
In reply to Rock to Fakey:

The metolius cams are great units - there is nothing much that can go wrong with them and theyare SUPER light. What you need to consider is that the BD unltralights are a product designed for people who want the ultimate in performance and are willing to part with an arm or a kidney to get it. The Metolius Powercams on the otherhand are very robust and will last for ever and a day - I have had TCU's since 1999 which are still looking good. Sure bits of them look worn and a bit raggy but what do you want for 17 years of use?
Rock to Fakey - on 11 Jul 2017
In reply to jezb1:
> Personally would avoid metolius if you do any sea cliff stuff. They corrode and seize very easily compared to other cams which is a shame.

Which ones perform better in these respects then?
Are the rest about as good as each other?
Post edited at 14:20
beardy mike - on 11 Jul 2017
In reply to Rock to Fakey:

BD, totem and fixe uses the same (more or less) steel combination as Metolius, i.e. high tensile chrome moly steel. I think the difference might lie in the tolerances of fit - seemingly Metolius spec high tolerances on their axle holes through the lobes which would be a touch more prone to seizing. That said I've personally nver had a problem but there again JezB gets more milage than me, certainly on sea cliffs.

DMM and Wild Country both spec 17/4ph h900 stainless steel which is a very high spec stainless and therefore you should see no interaction between the metals as long as you maintain them reasonable well. Theprevious combo in my opinion is also fine as long as you clean and oil your cams after sea cliff trips, especially when the seas are big.
jezb1 - on 13 Jul 2017
In reply to Rock to Fakey:

As Beardy Mike, who knows far more than I ever will about engineering says, other small cams use the same materials so I'm not sure why I've faired badly with the small Metolius cams (as have a couple of other people I know).

Edited to add: read his post properly about the tolerances, which is interesting.

I use Totems for the small stuff and Dragons for the bulk of my cams. I clean / lube them fairly infrequently and never have any problems with them.
chuffer - on 14 Jul 2017
In reply to David Barlow:

How about a cam lobe width field too? I sometimes think the superlight cams are light by reducing cam width as much as anything else - which would cut holding power somewhat so seems a bit of a swinge.
gethin_allen on 14 Jul 2017
In reply to chuffer:

> How about a cam lobe width field too? I sometimes think the superlight cams are light by reducing cam width as much as anything else - which would cut holding power somewhat so seems a bit of a swinge.

friction is a coefficient of pressure and contact area, pressure is a measure of force on an area. If you reduce the area and keep the force the same the pressure increases and hence in a linear world (hypothetical) the friction would stay the same.
The only way this would make a difference is if the pressure exerted was enough to break the rock.
beardy mike - on 15 Jul 2017
In reply to gethin_allen:

Yes friction is the same but pressure is not. As a rule of thump the force being applied through each cam lobe is equal to the force being exerted downwards on the sling so the point of a wide cam is not to provide friction but to reduce the pressure being exerted on the rock as pressure is force by area. The net result is that the pressure which is effectively the stress seen in the rock is less and is therefore less likely to fracture and break. This is particularly pertinent in soft rock areas but you have to also reckon that once friction is sufficient and deformation of the lobe occurs by crystals pressing into the metal, there is some degree of mechanical interlocking which occurs. If the crystals break you get left with debris at the interface which allows the surface to slide and the unit can pull out.
beardy mike - on 15 Jul 2017
In reply to chuffer:

I think more important than holding power in this case is that certain units which are double axle microcams have thinner lobes in a size where lateral forces from a poorly placed cam can be sufficient to snap lobes on fatter lobes cams... does that make sense? Brain a bit addled.

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