/ PRODUCT NEWS: New Wild Country Helium Friends - In Stores Soon
Read more at http://www.ukclimbing.com/gear/news.php?id=3461
This makes me wonder, DMM claimed they didnt want to use thumbloop with Dragons because thin slings cut through at too low KN ratings. Now we see Wild country cams with thin slings, and they are made by DMM anyway...
Other than that nice cams.
The slings are fatter than the ones on the DMM Dragons (12mm vs. 8mm), I think that's the key difference.
and they are used singly not doubled through so you can extend them.
thx for replies
Now a comparison with camalots would be interesting, on Weight versus camming range :)
Too much cam choice.....cannot compute.....cannot compute.....system now shutting down to prevent decision-making circuit burnout.
Any chance you could label the sizes on the graph?
The range has not changed in the sense you think it has (or that they want you to think it has?). A size 1 Helium has more range in mm than an old size 1 Tech not because of any new clever engineering, but simply because it is bigger. Clever eh?
Yeh, looks like they've just managed to be much more consistent in expansion range:
Size . Expansion ratio . Improvement
........ Tech ..... Helium
0 ...... 1.4615 ... 1.6071 ... 9.96%
0.5 ... 1.4118 ... 1.6099 ... 14.03%
1.0 ... 1.5263 ... 1.6098 ... 5.47%
1.5 ... 1.5217 ... 1.6100 ... 5.80%
2.0 ... 1.5172 ... 1.6096 ... 6.09%
2.5 ... 1.6667 ... 1.6102 ... -3.39%
3.0 ... 1.5349 ... 1.6103 ... 4.91%
3.5 ... 1.6078 ... 1.6099 ... 0.13%
4.0 ... 1.5625 ... 1.6100 ... 3.04%
Isn't time a Wild country boffin jumped in?
You're comparing apples with pears, though. The Helium sizes are larger than the Tech ones...
The only possible way they could increase the range is if the cam stops on the techs were positioned so that the tips of the lobes where greater than 13.75 degs (WCs camming angle) from the horizontal when the cam is fully open. This is because the smallest size is limited by the lobe tips coming into contact with the opposite side of the crack.
This would have been a stupid thing to do as it adds weight and decreases range for no gain and, from some crude measurements on my cams, I don't believe it is the case.
So I don't believe they have really increased the range at all and think that the increase they talk about in the marketing is achieved by comparing units of different size.
He's not comparing apples and pairs he's comparing the ratio of expansion calulated by taking the largest expansion and dividing by the smaller. This is not particularly size dependent (once you get out of the smaller sizes anyway). The cam manufacturers use a similar measurement also.
If you average this number across the range you'd get the average expansion ratio of the cams and is handy for comparing different brands.
I've done these type of comparisons before, one thing to note is the old WC figures are not very accurately measured which may account for some disparities.
Yes, I was interested to note that for the heliums they're quoting to 1/100th of a mm, while the techs (& 4CUs) were just stated to whole mms, presumably in order to maximise the gain in range.
Though am also curious to which unit, and how they measured it, the 'upto 20% greater range' comes from.
the expansion ratio (largest expansion mm divided by smallest mm) of C4 is generally over 1.7 whilst the heliums is close to 1.6. What this tells you is that if you take a C4 and create / find a helium with an identical smallest contraction, the C4 will in general expand by just over an extra 16% or so.
Acutally I think you have made an error in your percentage figures,
taking the size zero figures:
1.4615(old friends) ... 1.6071(new WC hellium)
lets imagine we are measuring in units of whatever the smallest contraction is and comparing cams of the same smallest contraction, then the expansion would be .4615 and .6071 respectively
therefore the percentage increase in expansion is ((.6071 / .4615 ) * 100) - 100 = 31.55%
It goes to show that the quoted sizes of the tech friends are not given accurately enough (a ratio of 1.67 isn't possible) for a proper comparison. As I mentioned in a previous post I doubt there is any real expansion gain for the heliums.
> It goes to show that the quoted sizes of the tech friends are not given accurately enough (a ratio of 1.67 isn't possible) for a proper comparison. As I mentioned in a previous post I doubt there is any real expansion gain for the heliums.
I take it we have both been drinking beer ;)
The range obviously is a function of size :P
The expansion ratio (max / min) is more size independent but is unlikely to be exactly the same in the smaller sizes due to limitations of scalling the materials but still retaining the required strength.
" will be very close to size independent as the only thing not making it so will be a rounded tip shape on the lobes."
and the thickness of the axel in the smaller sizes no? (as well as accuracy of manufacture and neccesary give between the parts)
I compared the published figures over a few brands a while back and they weren't as consistent as you seem to think they would be. Perhaps they are not quite as consistently designed / manufactured as you'd expect or maybe the published ranges are inaccurate as you mention.
Certainly the WC published figures for ranges pre hellium seem more variant than the design would suggest, more so than figures from most of the other manufacturers.
Ignore my comment, I'd only had a quick glance at the blurb and was under the (false) impression that the Helium sizing was considerably different from the old sizes, whereas it appears they are broadly equivalent.
The ratio will vary for camalots and dragons as the range depends on the spacing of the axles and this varies with their size.
technically if you are comparing expansion ratios of different manufacturers, as expansion ratios are fairly size independent it wouldn't mater if the brands you are comparing are considerably different in sizing (ie offset by half the increase to the next size between brands). You should however be comparing a range of cams for both manufacturers that span a similar set of placements (ie don't just compare WC zeros with the larger BD cams)
If the brands have a fairly consistent expansion ratio across the sizes (which most cams do apart from in the smallest sizes) then you can use that directly as a reasonable approximation, however if it varies you would need to compare EITHER the closest sizes directly, OR averages (ranged averages or overall averages) OR plot the expansion ratios against minimum expansion on a line graph to compare at specific intervals.
Yeah obviously for twin axel the exact spacing of the axels effects range but the actual expansion ratios vary less than you'd think based on size of cam (once you've taken in to account the random variance due to measurement inaccuracy)
OK, glad I asked, so they aren't much better; no gain in range, possibly lighter, assuming they bother to measure this accurately, and fresher looking, but basically no great leap forward.
Stick to dragons and c4's?
Buy up reduced tech friends?
well as I pointed out on the published figures there is quite a big gain in expansion ratio on the heliums compared to the WC friends (in the size 0 anyway), just how accurate those figures are we don't know.
The percentages Joe D calculated are not the (size independent) percentage increase in expansion, which I believe are more like roughly 3 X the figures he presented. But I agree with Kane in that the old figures WC quote for friends seem inaccurate, and that the new design doesn't seem to be a major break through, so take from that what you will. I haven't calculated that a camming angle of 13.75 should be an expansion ratio of 1.62 (meaning the helium are just standard expansion for a single axel 13.75 camming angle friend) as Kane suggests and he hasn't showed his math but I'm willing to believe it.
That said I really like the WC friends I currently own and the new design seems really nice with the thumb loop, plus they are lighter. You've not just got to consider the range of the individual units but how heavy they are and how well they function. If you can carry X heliums for the same weight as X - 1 C4s and cover the same range of placements to many people the heliums would be better.
I also really like my BD cams and zeros and my HB quadcams are looking a bit tired now. Looking forward to buying a dragon or two and will probably test drive a helium at some point :)
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