UKC

Interested in the collective wisdom regarding this critical and surprisingly complicated phenomenon:

Is there such a thing as too dry? I've heard popping of a hold called "dry-firing" before. I sometimes get very hard & visibly shiny-smooth skin which I'm sure is detrimental to sloper hanging.

Conversely - sticky wet? Does it exist? Certainly does on the beastmaker: it takes some very unique conditions to hang the slopers, what about rock? If so, which types? How wet?

Too cold? Sticky rubber stops being sticky, apparently. What about skin?

Too thick skin? In Ondra's documentry there is a scene of him sanding down his fingers with the explanation of "skin too thick".

Does antihydral help? Applied sparingly it certainly gives me thick & strong skin which doesn't sweat, but I seem more prone to slipping of holds, particularly indoors. Cant decide if this is due to less friction or less feedback - if I cant feel when I'm about to slip, I don't know to squeeze harder.

http://www.theshortspan.com/features/friction.htm is the best resource I've found but it raises more questions than it answers.

-ross

In reply to quiffhanger: I think there is, when it is bone dry and cold my hands slip off all the time but when it is a little bit more damp they seem to stick better. Maybe because the skin is softer when slightly damp?

In reply to quiffhanger:


Surely this is because this skin is more likely to lead to flappers?

In reply to quiffhanger:

Yep. There's even been some experiments to back it up! basically there's an optimum moisture level where you get maximum friction between your skin and the rock. Anecdotal evidence includes the infamous 'tacky damp' (presumably conditions that look too damp but turn out to be just right for hanging those heinous slopers) and some wad in the south-west who would only try his project (cider soak?) after a rain shower.


I don't think the rock type matters so much as how moist your skin is. If the rock itself is actually wet that's definitely bad for friction.


Cold air tends to be very dry. My guess is that this in turn dries out your skin leading to non optimal skin moisture level.

I think sticky rubber is meant to work by deforming to the rock, I'd guess there's some optimal temperature for stickiness that's in a range of temperatures likely to be found by your average climber (i.e. not -20 centigrade.) Presumably the rubber becomes less pliable when it gets cold, though I've got no idea how great this effect might be. Also, if your boots will get warmed up a lot by your feet.


As others have said this is more to do with stopping flappers.

In reply to quiffhanger:

When my fingers are cold the skin is a bit glassy and I can slip of anything sloping. But after 5/10 mins of warming up things change radically

In reply to Bulls Crack:

Most "friction" in skin/rock contact is due to how much your skin deforms around the small irregularities in the rock, so really the concern with conditions is how the material properties of your skin change with temperature and moisture and how this interacts with rock of different textures.

At the risk of simplifying things too much:

Cold/dry skin contracts and goes harder, warm/wet skin is more pliable and softer and expands slightly. Too hard/dry and your skin will deform too little and on smooth rock the friction will decrease. To a point however it will increase on rough rock as harder skin will tear less easily and snag better on crystals. Too warm/wet and the skin will not snag over larger irregularities (the skin is too stretchy), but to a point it will have better friction over smoother surfaces. This is partially the reason why you never get the "sticky/damp" sensation on grit, but you do on smoother limestone and beastmaker slopers.

This is also why all of the bollocks studies done in labs regarding chalk usage etc don't have any relevance to real life - they assume every hold is the same and that the interaction between skin and hold is always the same.

In reply to Hannes: Skin friction is something I'be been musing over for a while as I have quite a lot of trouble getting friction on slopey holds. I don't think its hand/finger strength neccessarily as I can use even very small crimps but could be wrong...I've found that using liquid chalk for instance instead of conventional chalk can mske the difference between being able to do a move or not and was wondering whether being an older climber with less flexible skin was a contributory factor....

In reply to quiffhanger:

For indoor comps, I would always wash my hands and 'touch dry' them just before I climbed, then chalk up. That clean, not quite dry feel for me provides the most friction.

In reply to quiffhanger:

Thanks all! Think I'm going to pay much more attention to this, rather than just chalking and hoping for the best. Time for some experimentation...

In reply to RupertD:

I think there are lots of secondary affects as well. As an example evaporating dampness on rock after a shower in warmish unsaturated air cools the rock quickly so friction can improve due to that (its not just sticky damp). The interaction of lichen with damp and humidity is also important.

I think the bollocks studies in labs are worse than you describe. Its almost as if they know nothing about how climbers hold holds and move from them in their experimental design. I've tried to get my sports science people interested in this but no luck so far (even volunteered it as a BSc or MSc project). If everyone tried with every department in the country we might get some useful info.

In reply to Offwidth: possibly because you exhibit zero understanding of how science works? yes friction is only one component of climbing 'grip' but you understand complex situations by devising experiments that minimise the variables to be measured. There's a
huge amount of work that could be done but dismissing what results we do have as 'bollocks' will ensure nobody takes you seriously..

In reply to i.munro:

I agree I'm not at good at science and engineering as I should be. However, I've survived getting a PhD in the area and teaching and researching the subject at University level for a few decades. Plus on the chalk front I've worked and played with plenty of top climbers and guidebooks and for the hell of it.

In reply to Offwidth:

Yes, yes Offwidth - but what have you ever done on grit?

In reply to Offwidth:

Then I assume you come up with something more constructive than 'bollocks' when reviewing papers and I would appreciate it if you could do so in this case.

In reply to Offwidth:

Yonks ago there was a thread on here where some bloke seemed very knowledgeable about the subject of friction and rubber. He reckoned the loss tangent of the rubber had a lot to do with how good the rubber was. Maybe the same works for skin. It was maybe 8 years ago but I'll see if I can find something.

In reply to i.munro:

You'll find most science these days is super competitive and excellent work is being rejected for funding on a regular basis. It make bollocks like that friction paper all the more galling. I've been constructive elsewhere providing suggestions for improvement.

What is depressing is that I respected your efforts on southern sandstone ethics and your obsessiveness with this silly paper just because it suits your negative views on chalk is below you.

In reply to Offwidth:

My 'obsession' with this paper is because it constitutes the only hard information that we have in an ocean of speculation & disinformation.
Look at this thread. Lots of answers to a perfectly valid question all given with complete confidence where the real answer is "we don't have a clue".

Odd that you seperate care for the rock from this. Both in SS & at Bleau the 3rd biggest cause of avoidable damage (after dirty shoes & climbing on damp rock) is brushing to remove 'excess' chalk.

The other two issues can (hopefully) be resolved by education. How can we educate on this until we know if there is even such a thing as excess.

If more chalk simply gives more 'grip' in all cases, as you seem to believe, then there is no such thing as excess & no need to brush.
If not, then those who do so believe can be so educated.

Either way the rock gets a bit of relief.

This paper describes almost exactly the experiment I would devise to answer this simple yes/no question (I would use larger hand pressure to put it firmly in the regime where climbers operate). It's basic pre-undergraduate physics. However it has been dicredited in the climbing community be a campaign of whispers & innuendo without substance. Silly - really?

Of course it can be improved/extended. Whose work can't? However you are constantly trying to discredit it all over the internet without giving any detail.

In reply to i.munro:


It may be the only source of hard information you have but writing `we´ is presumptive and hardly indicates good scientific practice in researching all the available information before coming to a conclusion.
The paper in question (Li et al)is not only rubbished because it is contrary to nearly every climbers experience (and I come from the pre-chalk days as well) but is in direct contradiction to the conclusions in a more considerably more scientifically convincing paper `Instrumented Climbing Holds and Dynamics of Sport Climbing´by Fuss/Niegl which appeared in Engineering of Sport Vol 6, a peer reviewed scientific journal.

Amongst their conclusions they state:- " Specifically the results of Li et al (2001) could not be verified: chalk is not a `myth´as it provides higher friction than a dry hand."
`

In reply to i.munro:

Both in SS & at Bleau the 3rd biggest cause of avoidable damage (after dirty shoes & climbing on damp rock) is brushing to remove 'excess' chalk.


is that a scientifically proved fact?

In reply to jimtitt:

Thanks Jim hadn't spotted that paper. Will read with interest.

In reply to Offwidth:
My pleasure sir

In reply to jimtitt:

I, unfortunately, don't have a PhD. I do however know that, in the vast majority of cases, if I was to be left stranded on a cliff in either

a) climbing boots but no chalk
b) good trainers and a chalk bag

I'd go for b) the majority of the time.

Boots need to be warm enough to work properly. If the air/rock is cold and your feet are too, then the boots won't warm up enough, and their frictioanl qualities will be reduced. It's a lot like winter and summer car tyres, but boot manufacturers tend not to produce the 'winter tyre' version of boots. I'm fortunate enough to have some however, it really makes a difference.

As for skin. Well, there comes a point when your skin becomes too dry and vaneered, it's rubbish then. I've spent as much time spitting on my hands today as chalking up in order to keep their friction up.

So, as for the "mysteries of friction", yes, it does improve as the temperature drops, but only to a point and then cold boots/glassy skin/cold muscles become more of an issue and the benefit is lost and you'll expend more energy trying to keep skin and boots at the ideal temperature than is beneficial to climbing efficiency.

In reply to andi turner:

Why on earth do you think I wanted to know any of that? Perhaps you meant to adress your post elsewhere?

In reply to andi turner:

Please ignore Jim and feel free to ramble like that anytime.

In reply to jimtitt:




I have read that paper & will happily admit that I failed to understand how they got from their measurements of instantaneous 'friction' ( the ratio of outward to downward force) to their quoted numbers for static friction.
If you do understand this a pm would be appreciated.

If we simply accept their numbers as given though, they only find an increase in friction with powder chalk (over a dry hand) on a 'clean' surface. (again it's unclear what they mean here).
On an already chalked surface they find a drop in friction to below that for a 'wet' hand.

Results exactly in agreement with the Birmingham paper & both consistent with there being such a thing as 'excess' chalk.

This, I would argue, is exactly in line with many climbers experiences - or do you think everyone buys expensive boars-arse brushes for fun?

In reply to Dave Reeve:
Skin friction is something I'be been musing over for a while as I have quite a lot of trouble getting friction on slopey holds. I don't think its hand/finger strength neccessarily as I can use even very small crimps but could be wrong.

I think skin condition plays a big part in whether or not you can hold a sloper but I'm not convinced it is the main factor.
Slopers seem to be much more body position and tension dependent than positive edge holds, you also seem to use different muscles. For me I've found the wrist, elbow and even shoulders are more important that fingers with sloping holds as you are often pulling to keep your hand in place*. My finger strength isn't as good as it was when I was regularly training it but imporvements in my upper arms and core have made a big difference to slopers.

*(if that made any sense what so ever!)

In reply to Reach>Talent:
Indeed. You need to press down on slopers to generate maximum friction and this means strong upper arms and shoulders. Although also fingers

In reply to andi turner:


Sod all the science, Andi's comments are supported by observation in the real world though the impact of cold muscles and glassy fingers will vary from person to person. Then there is the issue of the legendary "sticky damp" - I am a believer.

In reply to Kafoozalem:

In science the mystery of sticky damp is second only to the Higgs bosun. Perhaps CERN will reveal all....

In reply to i.munro:

As far as I'm aware nobody sensible at any point argued that excess chalk (on a hand or the hold) didn't decrease friction. The point I and others were making is chalk if used properly does help grip. The only paper that did state chalk reduced friction was a flawed piece of research that contradicted the experience of armies of seriously good climbers.

What is so ironic is that I suspect most occasional climbers and many regular climbers are ignorant about chalk utility. Several good folk here on UKC try to argue why one should minimise chalk use and try to understand correct chalk use, such that it will improve grip and make less of a mess on the rock. I think these attempts at help are seriously undermined by your repeated views (and Bruce's) which distract and contradict and hence help the lazy or the unconvinced ignore this well meaning educational message.

In reply to Ben Stokes:

The energy levels in CERN are not currently high enough. The theoretical Physicists need the Greek debt to improve the system so they might unravel sticky damp. There will be spin offs like Teflon to help cover the costs and slip them along to a Nobel prize.

In reply to Offwidth:


Totally agree.

Apropos of not very much, I'll just add a small observation. I recently visited an always neglected venue, that hadn't been climbed on for weeks. With the lack of climbing and the wet weather almost all the chalk had been washed off. It was like discovering a spot all over again. None of the dots were marked, I had to work out sequences all over again (or not). It was a refreshing experience and reminded me of when I first started and chalk was still quite the new thing.

I still used chalk obviously, but probably a little bit less and brushed a bit off afterwards.

In reply to Offwidth:


I would strongly disagree. Among those who actually think about the subject I've found a vast spectrum of opinion (& many believe that chalk always increases friction. Some even chalk the soles of their shoes).
How can you then discuss 'proper' use (your words) when there is no consensus & no objective evidence on what that might be?

Worse, on entering the sport (typically now at a climbing wall) people are simply told "put this on your hands. They'll stick better" & most give no further thought to it.

If instead they were given IMO a more accurate summary.
" Some believe that this stuff increases friction but the only objective evidence shows that (at least beyond a certain amount ) the opposite is true." then people might be more open to a more nuanced view.

NB there you go again. "flawed" "bollocks" "silly" but nothing to back it. It's like arguing with creationists & yet in your first sentence you agree with their findings.
I give up.

In reply to i.munro:
A wonderful bit of writing, worthy of the finest Westminster spindoctor!

" Some believe that this stuff increases friction but the only objective evidence shows that (at least beyond a certain amount ) the opposite is true."

Some believe A very weighted statement given it is the majority opinion and is backed up by just as much science as the counter position.

the only objective evidence shows that the opposite is true This statement is factually innacurate.

Adding this (at least beyond a certain amount ) just makes it pointless rather than factually innacurate: Water, oxygen and vegetables are only beneficial upto a certain point.

You've taken a perfectly reasonable and accurate statement "Overuse of chalk is detrimental to the frictional properties of a hold" and warped it out of proportion.

In reply to i.munro:

I think a more balanced statement would be

"The vast majority of climbers believe that this stuff increases friction but one scientific study shows that (at least beyond a certain amount ) the opposite is true, another more recent study saids the study was flawed. However everyone agrees that using too much chalk decreases friction"

I don't know what your agenda is but it seems stupid to focus on one flawed study and to ignore the experience of millions of climbers.

In reply to quiffhanger:

I often have problems using tiny (and sometimes even quite large) slopers, and am relieved to find that this is solely down to my skin being of the wrong type . . .

In reply to i.munro:

"I would strongly disagree" again more damage to the cause. What are beginners reading this to think when we both agree minimal chalk use is the best policy?

"Among those who actually think about the subject I've found a vast spectrum of opinion (& many believe that chalk always increases friction. Some even chalk the soles of their shoes)." ....OK then give me some named examples as I can't think of a single thoughtful experienced climber who thinks lots of chalk helps or chalk on their shoes helps.

""flawed" "bollocks" "silly" but nothing to back it." ...only the experience of all those top climbers; reading the paper and describing the clear flaws in their experimental set-up; plus now the new paper that dsiagrees with the main point of difference we have.

In reply to i.munro:


Where does POF sit in this league table of bad stuff...

In reply to quiffhanger:

Here's the thread I was talking about earlier.

The bloke Richard J seems to know what he's talking about.

http://www.ukclimbing.com/forums/t.php?t=57899&v=1#x771933