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Friction fiction

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 Cobra_Head 24 Jun 2020

I've just read another thread, where someone mentioned they prefer colder high friction days.

Now, I'm not a good enough climber to maybe notice , but I'm not sure there's more friction on colder days that warmer one's, at least feet-wise. Oblivious you sweat more so your hands may be slippier, but shoes?

Formula one drivers go to great lengths to keep the temperatures of their tyres up, for increased friction, why are shoes different.

Is cold = better friction a myth many people have fallen for?

Has anyone ever tested shoes to find out, scientifically.

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In reply to Cobra_Head:

It's rarely shoes that are the issue. It's fingers/hands. 

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 nniff 24 Jun 2020
In reply to Cobra_Head:

I remember his argument going on for years - IIRC, the accepted answer is that racing tyres work in a seriously dynamic environment in which they have to hold their shape around the road surface for a fraction of a second and they work at high temperatures generated by the load they manage.  Shoe rubber moves at a slower place and so needs to hold its deformation over the surface for far longer - so cold is good over the usual norm for performance in extreme conditions (i.e. truly shite holds and not a lot of rubber).  Shoe rubber is a compromise for durability and general stickiness.  

Or something like that.

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In reply to Cobra_Head:

Honestly, you don't need to be a particularly good climber to feel the difference. Just jump on any grit problem at your limit in the summer and then try it again in winter.

I have had hot Cornwall granite peel a whole layer of rubber off my shoes before, it's the weirdest feeling. You are standing on a pretty big slopey hold that should be sticky as hell, you have your whole weight on it, yet somehow you are slipping down it and once you're off you find that your shoes have been practically destroyed. That doesn't happen in the cold.

Edit: When I say peel, I don't mean it melted the glue, I mean it gouged the rubber itself.

Post edited at 17:59
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In reply to Cobra_Head:

Cold makes a significant difference.

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 wbo2 25 Jun 2020
In reply to deacondeacon: Disagree.  As I said in the other thread I did some granite'edgy' routes in 4-5C earlier this year.  repeated them a week or so in temps at least 20C highe in the same shoes.  The rubber in the repeat was much, much softer, and was deforming on edges rather than being supportive.  Smearing was easier, but I'm not sure of the effects of the rubber shearing ..

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In reply to Cobra_Head:

I'm a total punter but I can climb about 2 full grades harder on grit (trad or bouldering) in cold conditions compared to hot and I think I'm with the majority on this, most of my more hardcore friends don't even countenance grit from may to October. I was up on the kinder northern edges yesterday and it was still way to hot up there to hang anything vaguely slopey with any confidence! I think it's more about sweaty hands than feet. 

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 Cobra_Head 25 Jun 2020
In reply to Thread:

Thanks for the replies.

I've not noticed any difference, feet-wise.

We used to go to Spain quite regularly, and my grades don't seem to drop off significantly, but I'm only pushing 6b+s at most.

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 annak 25 Jun 2020
In reply to Cobra_Head:

The rock type and climbing style is also worth taking into account, consider the amount of friction on gritstone vs Spanish limestone, and how crucial that friction is for being able to climb the route in question.

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 Cobra_Head 27 Jun 2020
In reply to annak:

> The rock type and climbing style is also worth taking into account, consider the amount of friction on gritstone vs Spanish limestone, and how crucial that friction is for being able to climb the route in question.


I did consider that, i.e. massively more friction on grit and granite, but what about English limestone and Spain limestone?

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 Si dH 27 Jun 2020
In reply to deacondeacon:

> It's rarely shoes that are the issue. It's fingers/hands. 

Hands are more critical but feet are also affected to an extent. Trying to climb smeary Font 5/+ boulder problems somewhere like  Cratcliffe is pretty hard in summer.

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 Si dH 27 Jun 2020
In reply to Cobra_Head:

Limestone friction is also better when it's cooler. It isn't as important as on grit because the holds are sharper and more positive so the friction is less important, but to climb something right at your limit, it's definitely easier at 15C with a nice breeze.

Post edited at 17:13
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 Cobra_Head 27 Jun 2020
In reply to Si dH:

> Limestone friction is also better when it's cooler. It isn't as important as on grit because the holds are sharper and more positive so the friction is less important, but to climb something right at your limit, it's definitely easier at 15C with a nice breeze.


How come my grades don't change when I go abroad then? In fact I usually climb harder abroad than here.

I'm still not convinced, I can see it's better hand wise, but not feet.

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 jimtitt 27 Jun 2020
In reply to Cobra_Head:

Everyone climbs "harder" at Kalymnos, nobody does at Ceuse.

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 afx22 27 Jun 2020
In reply to Cobra_Head:

Because edging on limestone is complexly different to smearing on grit.

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 Cobra_Head 27 Jun 2020
In reply to afx22:

> Because edging on limestone is complexly different to smearing on grit.


I'm comparing two limestones!!

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 Cobra_Head 27 Jun 2020
In reply to jimtitt:

> Everyone climbs "harder" at Kalymnos, nobody does at Ceuse.


I've never been to Kalymnos or Ceuse, but I take your point, but are you suggesting the places I'm climbing abroad, not a single venue and in a few different countries, are all graded lower than the UK?

And that, the grades I climb here, just happen to be under-graded enough to take into account the difference in friction to exactly match my UK graded? It seems a very neat coincidence.

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 Rob 27 Jun 2020
In reply to Alkis:

I've experienced exactly the same on Cornish quarried granite routes on (rare) hot, sunny days. Never understood why...

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 afx22 27 Jun 2020
In reply to Cobra_Head:

Fair enough.  I’m not sure where you normally climb but assumed it was on the grit.  My mistake.

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 wbo2 27 Jun 2020
In reply to Cobra_Head:  limestone can vary in properties as much as comparing sandstone and limestone.   So beware generalisations.  

Where do you normally climb in the UK.  But Jim's point is fair.. go to Ceuse and you won't magically get a holiday boost.

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 apwebber 27 Jun 2020
In reply to Cobra_Head:

Cold hard rubber if you want to stand on small but positive edges and crystal nubs. Friction isn't an issue.

Warm soft tacky rubber if your holds are friction dependant.

In cold weather (good for hands) you can scuff your shoes on a bouldering mat to warm them up and gain a little more tackyness.

Post edited at 20:23
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 Webster 27 Jun 2020
In reply to Cobra_Head:

There is definitely a degree of self perpetuating myth when it comes to cold = more friction. the optimum conditions for all rocks, hands and feet are probably about 8-15deg, shade, low humidity and a light breeze. too cold i.e. close to freezing, will mean reduced friction for feet, and reduced feel for hands. different rubbers have different optimum temperatures such as summer vs winter car tyres. i expect the rubber used in most shoe brands is specifically chosen to be most effective at temperate temp. ranges as that is the temperature range that will be climbed in for the most people most of the time.

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 john arran 27 Jun 2020
In reply to Webster:

There is zero doubt, learned from experience, that slopey gritstone smears and edges are easier to hold when the temperature is notably below 10deg than when it's above. Theory is all well and good, though seemingly still somewhat speculative, but the practical reality of wanting to climb hard grit with a real chance of painful failure means that climbers involved in that game learn fast or get hurt.

I don't have the scientific answers to prove a case, but self-perpetuating myth it certainly isn't.

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 Cobra_Head 19:40 Sun
In reply to afx22:

> Fair enough.  I’m not sure where you normally climb but assumed it was on the grit.  My mistake.


We don't normally have a"normal" as we're miles from anywhere and it's about he same couple of hours to climb on grit of limestone.

I ddin't mean my post to sound stroppy, if it did.

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 Cobra_Head 19:48 Sun
In reply to Thread:

Thanks for everyone's input, though I'm still in the dark and not convinced from my own experience.

The only thing I can think of is that I'm probably not pushing my grades that much to discover the difference, which might be true, as I'm not that bothered about chasing grades.

So maybe it would become more apparent if I'm on the verge of falling off more regularly.

Having said that though, I'm still not sure why my climbing aboard wouldn't see any marked difference in grades, the whole of Europe can't be graded so perfectly easier to match what I normally mange at home.

Cheers,

Pedro

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