UKH

Apologies if this has been done to death before but why do we think that grit is easier in the cold? Doesn't rubber get stickier as it gets warmer, which is why racing cars warm their tyres up? Does cooling down the grit, which is essentially a mishmash of inert silica crystals, by 20 C or so really change its frictional properties? 

However, I do get the point that grit seems harder on a hot day when things are 'sweaty' but is this just because of the humidity? Or because the algae etc. comes alive on such days? Are these sharp, clear and cold winter days good for grit just because humidity is low, and would a hot and dry day be better due to warmer rubber?

In reply to Red Rover: Cant talk about grit but repeated some granite routes a week or so.. maybe comparable to quarried grit ... last time I climbed them it was circa 20C lower and Iwas in a down jacket..  it was a lot harder in warm conditions

1. Much sweatier, greasier now to the touch.

2. Shoe rubber (XS edge) was much softer, and initially small edges, crystals felt less secure as I could feel the rubber deforming

In reply to Red Rover:

I suspect that grit is easier in the cold. No idea why!

It's also not the only rock that this applies. Having been shut down on Dexter (VS 4b) (limestone) in the blazing sunshine, I returned a week later when it was in the shade and it was like night and day. I thought in the blazing sun it felt 5b, and was more like 4b in the shade.

I believe that this carries across to other routes in the Avon Gorge. If there is a section that relies on smears on ripples and tiny features, I've found them much easier in the shade.

In reply to wbo2:

OK point 1 seems to be more about humidity than temperature. On point 2 maybe that is the answer, warm rubber is too soft for grit?

In reply to knighty:

I agree that grit etc is actually easier in the cold I just don't understand why. Maybe it's more the humidity than the heat that's the problem, or soft rubber doesn't work as well on small smears. 

In reply to Red Rover:

I don't think it is humidity. As the temperature drops, the relative humidity increases and it becomes closer to the dew point.

I think it is likely down to rubber being too soft. That said, what shoes are the pros wearing when climbing the superstar grades in hotter countries?  

In reply to Red Rover:

My first thought was the humidity, but as someone said, cooler temperatures = higher humidity. Maybe it is to do with your skin temperature, cooler skin = less sweaty? On the best days you can feel the crystals biting into your skin, on others you can almost feel the thin layer of moisture getting in the way,

Chris

In reply to Chris Craggs:

Cooler temperatures = higher RH for the same mass of water per m3 of air.

The same RH at a lower temperature has way less water than higher. Posting on a phone, so a bit brief

In reply to Chris Craggs:

Rate of evaporation of the sweat on your hand I would say is a Biggie

Was bouldering yesterday in 20 degrees in the sun on slopers (granite not grit) which I would normally not do but the wind was 25/30 mph and friction conditions felt like 10 degrees cooler at least

I normally associate cooler cons and particularly skin temp as a big factor in what I can hang 

In reply to Red Rover:

There’s a definite difference.

Some holds and foot positions can feel impossible in warm temperatures but almost sticky in the right conditions.  I prefer around 4 degrees Celsius but some of my climbing friends prefer a few degrees warmer.  They struggle with cold fingers.  There’s more to it than that - but all things being equal, cooler is better.

How much friction matters, depends on the climb in question.  If you’re at your limit of friction and keep slipping off, then try again in cooler conditions and it’ll feel completely different.  However many holds aren’t dependant on friction so much and can be climbed in warm conditions.  Slopers, smears and thin crimps are easier in cool conditions.  Jugs, compressions, positive crimps, certain jams can be fine in the heat.

Many grit climbs do require friction because there are usually a limited number of holds available.  Whereas I’ve been on limestone today, where there are loads of holds and it’s less about friction.

In reply to Red Rover:

Not just grit, Tommy Caldwell and Kev Jorgensen climbed the dawn wall in December and often at night as the friction is better. I couldn’t understand why either but Andy Hardy’s answer below makes sense.

If I understand the science correctly, if you have a given amount of water in the air, decreasing the temperature makes them move around in the air less which decreases the RH. So assuming it’s a dry day, a lower temperatures means water molecules moving around in the less so you get more friction.

In reply to Red Rover:

In cold weather gritstone actually contracts slightly,  making routes and boulder problems shorter than on hot days. Or something.

In reply to Red Rover:

to a certain extent if its red hot then grit can feel harder to climb.  'grit season' is over hyped in my opinion as you can still climb harder routes in the summer.

also if its too cold then it can feel hard as your body just cannot retain any heat and you cant perform well.

In reply to Iamgregp:

The colder the air is, the less water it can hold as vapour before it condenses out as rain (dewpoint). Air at <0C is going to be dry, as the water will be frozen, RH is the ratio of water in the air (kg/m3) divided by amount that it could hold at that temperature. If the RH is 100%, it's raining. It's why summer rains are heavier.

On a cold dry winter's day there's basically bugger all water in the air. 

Having said all that I'm proper nesh so I stay inside when it's cold 😉

In reply to Andy Hardy:

So you are saying it's about humidity effects rather than rock temperature? That would make sense. I'm not denying that grit is easier in the cold but I always doubted that this was because was of the temperature of the actual rock, as silica probably doesn't change much over 20 C. 

In reply to Red Rover:

I think it's to do with the skin / rock boundary.

Skin will sweat less or not at all, but needs to remain pliable to deform into the surface. If you have good circulation, fingers stay warm enough to keep the skin pliable but not warm enough to start sweating hence lubricating the surface.

Edit the bit about RH was originally to explain why even if the humidity reading is higher at a lower temperature there can be less water than the same reading at a higher temperature

In reply to Andy Hardy:

Brilliant explanation, thank you!

In reply to Red Rover:

I have heard this too and some folk have suggested that sticky rubber-soled rock slippers work better in warmer temperatures.

Overall, though, most climbers find cooler temperatures easier. I can certainly identify with this - I have an even more marked preference for cooler temperatures while climbing any rock type. Getting less sweaty hands certainly helps, but in general I feel far more comfortable overall in colder temperatures. Perhaps the arduousness of rock climbing is a contributory factor? - There's no question that hard exercise warms the body up and colder temperatures produce a generally more "comfortable" situation overall when rock climbing. I feel listless, dehydrated and lethargic in hot conditions. I pour with sweat and I find it hard to climb any rock type when the temperature is much above 20 C. Perhaps these factors (coupled with humidity generally being much lower at colder temperatures) offsets greater stickiness of rubber in warmer temperatures.

Although footwork is always essential, I would imagine that at the higher grades that handholds must become relatively more important too.

This is just my personal experience, but I'm keen to hear a fully rigourous scientific explanation for this phenomenon.

In reply to Red Rover:

The answer are already here...


Colder temps help with sweating, so you don't grease out smeary holds or slouppers.

The other thing is humidity. The colder it is, the smaller the absolute humidity is (so actual amount of water in grams per cubic meter of air). This is what counts. The higher temp of the air, the greater amount of water it can hold before reaching dew point...

So again, both help with friction.

As for the rubber on the shoes... yes, they will be softer in higher temps... but when you have softer rubber, it is also more prone to shearing (which is what can happen on standing small crystals, nubbings and so on). But as climbers (unless you're Johnny Dawes) rely more on yer hands than yer feet -> best to go with conditions where yer hands are more likely to stay on the holds than the minute performance gains of higher temps on the soles (when you'll be slipping off every hand hold).
 

In reply to Red Rover:

I think a big part of it is to do with your skin rather than the properties of the rock changing. Your hands will get greasy quicker and you just can't grip as well. There may be contributing factors like humidity but the big one is your skin. You feel it most on rock like gritstone because the climbing style relies more on friction rather than pulling off incut edges you'd find on say Borrowdale volcanic.

This may be nonsense but I've also heard porous rocks can "sweat" in the heat, when they have moisture inside them. When heated that moisture expands back out to the surface and leaves the rock but causes the surface to feel greasy. Again, probably a load of crap but just something I heard once. 

 

In reply to Red Rover:

It's pretty well established that cooler weather help with friction on marginal smears (you wouldn't be doing E10s in winter if it wasn't necessary)

There was quite a good thread on this a while ago.  Apparently the rubber on climbing shoes gives max grip at 5C.

Personally I'm not sure I've ever noticed the effects of warm weather in a negative way other than in discomfort from heat etc but I don't think I've ever climbed hard enough that the positive aspects of warm weather are outweighed by the lack of grip in my boots

In reply to Iamgregp:

To the 5 dislikes - why?

Is it because I've misunderstood the science (which I don't think I have entirely)?  Why don't you try explaining it instead of just hitting the dislike button?

Or is it because the thread is about gritstone and I've mentioned something other than grit which I know often doesn't go down well as if it's not on grit, well it's just not proper climbing is it?

In reply to Iamgregp:

You do realise that, having used the word 'dislikes' in a post, you'll now be subject to the attention of jesters far and wide in attaching ever more dislikes to your new post?

That's why I make a point of never ever using the word 'dislikes' in any post I ever write. Without exception

In reply to john arran:

That ship sailed a looong time ago, but I usually only get 2 or 3 people who follow me around, I got 5 this time so I thought at least one of them might be genuine?!

In reply to Iamgregp:

I've not disliked your post but it is hard to see how water molecules in the air are the defining factor in determining the friction between rubber and hard surfaces. 

In reply to DubyaJamesDubya:

Ummm I don't know how to answer this?  

I can appreciate it's hard to understand but there's quite a lot of posts in this thread regarding humidity, and how if the humidity is higher there is less friction, and the relationship between temperature and humidity.  

So yeah, water molecules in the air are a factor, maybe not the defining factor, but when we're talking about very fine margins, climbing in colder, dryer conditions may just bring about enough benefit to get the route sent. 

Of course if you were climbing in a absolutely  dry vacuum with then temperature would have no affect of course.  Probably get great friction on those lunar crags.  No need for pads or ropes either, come to think of it...

In reply to Iamgregp:

I don't see the link. How come Grand Prix tyres work better at high Temps then?

This article offers some good info:

https://www.climbing.com/skills/learn-this-friction-science/

In reply to Red Rover:

https://www.climbing.com/skills/learn-this-friction-science/

In reply to DubyaJamesDubya:

Not a bad point that, to be fair...

Damn. Just when I thought I was beginning to understand it

In reply to DubyaJamesDubya: because grand prix tyres are designed to gave the best stickiness at high temps whereas rock shoes aren't.  The only real comparison, similarities are that both are affected by temperature and are designed to behave best at a certain temperature.   

In reply to Red Rover:

Anecdotally, yesterday I could barely stand up on good smears on a (British 5a) slab, let alone complete it. Today I've just ticked a shady sloping f6A+ without any drama, in the same shoes, and felt like my feet were superglued to the rock wherever I put them.

Temperature is everything, for shoes as well as hands. I think the warm rubber tends to roll off holds much more easily - it's not stiff enough to resist deforming and rolling off the hold when it's too hot is my educated best guess - and it's obviously more marked with softer shoes. Turning up to the crag with Mythos yesterday was a big mistake!

In reply to wbo2:

If such things can be designed (formulated?) Why would you design rockboots to be stickiest at temperatures close to 0C, rather than say 20C?

In reply to Andy Hardy: what would you wear at 4,5 C?  Rubber changes with temperature- you have to pick one,  and you may not want to alienate northern Europe 

You've never put your shoes down your jacket to soften them up?   Ot don't remember the old Kalmes that were so soft a compound they stuck to anything, but wore out so fast they had to change the rubber?

In reply to wbo2:

If I were marketing boots, I'd be formulating summer rubber and winter rubber, and hence selling twice as many boots! 

In reply to Red Rover:

I think I read somewhere that a manufacturer designed their shoes to be at their optimum at 4 degrees Celsius, to align with optimum climbing conditions.  I assume this is to be where the climber sweats less and the rock has its best friction (whatever the science of that).

It makes sense to me to have shoes, the climber and the rock, to all have an optimum performance range around a single temperature.

In reply to afx22:

Although, as pointed out above, I'm very surprised a manufacturer hasn't marketed shoes for warmer conditions. Given the amount of climbing that takes place in warmer climates.

In reply to wbo2:

That was the point I was making.

A few random tips from experience: 

All rock types are easier to climb in cold weather but grit particularly - I have no idea why

Lowish humidity is also an important factor. Again I have no idea why. If humidity is too low than rock can become ‘glassy’. This is more obvious on limestone but rubbing spit and chalk into your fingers to break up the skin helps

Wind is really useful so select buttresses with an on crag wind for warmer days. Lots of boulderers take their own wind to the crag these days in the form of portable fans - the bigger the better

In comparison to other rubber Stealth comes into its own at low temps but is poor at warmer temps. At lower temps with other rubber types it can make a difference to tuck your shoes inside your jacket to keep them warm between goes

In reply to afx22:

<sraky mode> Make perfect sense then you look at where most of the climbing os done in the world, we nearly all climb at 4 degrees, so let's design shoes to work best at that temperature!!

</sarky mode>

This post makes no sense at all for mass manufactured shoes.

In reply to Red Rover:

Ok, so imagine climbing shoes could be designed to perform at their best at whatever temperature the designer chooses.  So let’s say 18 degrees Celsius...

But we can’t change when the rock has the most grip.  And we can’t change the temperature at which we sweat.  That’s out of our control.

Then the shoes would be a weakness in cool conditions.  In warmer conditions the shoes might work better better but the rock and our fingers are not working at their best then.  There would always be a weakness.

If shoes are designed to be at their best at the same time as when the rock has most friction and when our fingers sweat the least, then there is an optimum temperature band when everything works at its best. This is when it’s most likely that people can push their grades.

Btw I’m only repeating something I read by a shoe manufacturer, a few years ago - where said their rubber was designed to work best at 4 degrees Celsius.  I can’t remember where I read it or who it was by.

In reply to Red Rover:  don't forget the size of the shoe affects its ability to smear and edge too 🙂.  Plenty of parameters to vary.  But maybe try going out on warm and cold days?

In reply to Red Rover:

I remember years ago, in my first year of bouldering, I’d heard how conditions made a difference but didn’t pay much attention.  I climbed all summer, often going up to Almscliff, three times a week.  I ticked off as much as I could and I failed plenty.  I was just enjoying climbing as much as I could.

By autumn, I’d run out of easy problems and my failure to success ratio went up.

Then winter came but it was wet for ages, and I could only go at weekends, so I had to wait and wait.  

Then there was one specific day in early March that I remember.  It was the first crisp day that I’d been able to get there.  I ticked off 16 problems that I’d tried many times before.  They almost all seemed easy all of a sudden.

I hadn’t been training and wasn’t noticeably stronger.  It was then it dawned on me just how much conditions made a difference. 

Btw. The difference on grit is far more pronounced than it is on limestone.

In reply to afx22:

Shoe makers are missing a trick: there are 100 punters to every 1 wad. And punters enjoy climbing in nice weather.

In reply to afx22:

That makes sense if you are selling shoes to the 1 % of climber who take it really seriously in that they have long-term projects where they wait for the colder temperatures. Why not make shoes that perform best at 15 to 20 C when most of the world's hobbyists are out and sell 99 times as many pairs??

In reply to Red Rover:

I get the point and they may be missing out on market share.  I’d assume that most people within shoe development, such as sponsored athletes fall into the 1% who want performance in ideal conditions.

It would be interesting to ask shoe manufacturers about their design philosophies.

In reply to Red Rover:

When it's cold you don't notice the pain in your fingertips.

In reply to Red Rover:

Grit is definitely easier when cold and/or with low humidity. Unfortunately, the older and stiffer and less flexible I get, the worse I am in the cold. So warmish days are my preference now!

In reply to afx22:/CobraHead:  you'd end up in the old situation then when 5.10s were reputed to have the best rubber ...  dry and 4C are the best conditions for your fingers...  but your shoes would be rubbish unless you used brand X that were designed for 4C.   People would resolve their own shoes with 510 rubber so they could wear shoes that fit them but still get the performance.  

Personally I suspect people in the UK want a shoe that works well the 50 weeks a year they aren't on holiday..

Also at 15C the performance drop off isn't that great, but try a hot quarry at 25C in the air - very different!

In reply to Andy Hardy:

From some arguments presented here climbing in summer might be easier if we went back to the old days of less sticky rubber, with harder soles with less heat deformation. Must dig out my old EBs and Masters (probably too age hardened by now though). 

Edit: Perhaps letting modern shoes mature for a few years might improve their warm weather properties.

In reply to Andy Hardy:

They aren't missing anything. The people who don't care enough about climbing harder to climb in colder conditions also don't know/care enough about the optimum performance of their shoe rubber and their shoe rubber isn't going to be the limiting factor in their climbing performance anyway.

In reply to UKB Shark:

I have always felt that the primary advantage of keeping my shoes warm on cold days is in stopping my toes from going numb so I can feel what is going on.

If I forget and have an attempt with cold shoes and feet, I am more likely to fail because I don't trust a foothold or because I don't place it right due to lack of feedback than I am to fail because a well placed and weighted foot slips.

Either way, keeping your shoes warm makes climbing in the cold both easier and more enjoyable so I'm not that bothered what the mechanism of improvement is.

In reply to SDM:

And to sell shoes, you get wads to wear them and put the pictures on Instagram or whatever.

In reply to Jon Stewart:

That does seem to be a sign of the times; a spillover to some extent from our "celebrity culture".

Obviously, not just limited to rock shoes.

In reply to SDM:

A quick way to warm the inside of your shoes is to breathe into them a couple of times. 

In reply to Red Rover:

personally yes I, the other day at the roaches think it was the 23rd June?? in the morning it was very cloudy and windy first route of the day was Diamond Wednesday (HVS 5a), which if you have done, has some very small feet on it. Later on when the sun came out to play I was on Safety Net (E1 5b), and I just couldn't commit to using the tiny feet, also the hand holds just felt so greasy, so I backed off it. I have found this on many other occasions also Commander Energy (E2 5c) again tried on a hot sunny day, wouldn't commit on the top lay back, came back on a much cooler day felt a walk in the park. 

I know this all my own personal experience but there does seem to be some common factor, I usually climb a lot more confidently on the grit when its cooler, and have herd quite a few other climbers say the same. 

also just another note reading through the Western Grit guide book, on the conditions section for Wimberry it says 'grades here are given for perfect conditions' I presume colder conditions ? not having been there my self some insight may be appreciated as it looks amazing !! thanks 

In reply to justdoit:

Thanks. I do agree that grit is easier in the cold I just wondered why. Perfect conditions for Wimberry are rare I would just go when you get the chance and adjust your grade accordingly. Tough crag but one of the best! 

In reply to SDM:

Well what about people who want to climb harder when the weather is good?. Are you saying that you only try hard on the 5 days a year that it's dry, 4C and you're not working? What about those who suffer from Reynauds? Or those who enjoy ice climbing, are they to be dismissed as unwilling to try?

In reply to Andy Hardy:  good weather for climbing is <10C with a refreshing breeze .. dont confuse warm with good.

 Or use a shoe with more edging,,, the warm weather will soften them nicely 🙂🙂

In reply to justdoit:

Unless you're climbing in the high E numbers then you're probably climbing cracks at Wimberry so you actually want a nice hot, dry spell to dry them out properly. Being north facing the rock stays cool anyway, rarely seeing the sun.. some of the cracks feel like you're sitting in front of an air con unit

The boulders are a bit more hit and miss, lots of friction moves down there so you ideally need a cold and dry spell, hence the rarity.