Rope friction · AditNow Community

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gNick
50.2% (Neutral)
Newbie Topic Starter

10 years ago

I am getting rather baffled by the friction from ropes.

My 11mm Mammut rope, fairly new, runs pretty freely through my not worn Stop whereas my new 9mm Cordes Courant Equiral (washed as directed but with surface mud) was running so slowly that I had to feed the rope through the braking crab - it was a short pitch so I didn't unhook the crab.

I've noticed this before, where a thicker rope you would assume would be slower is faster.

Is this just the way things are or am I just suffering from an anomaly in the space time continuum which is modifying Newtonian physics?

Don't look so embarrassed, it's a family trait...

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RJV
50.2% (Neutral)
Newbie

10 years ago

Setting aside obvious variables such as wetness & muddiness, have always found that the different widths react pretty much as you would expect which probably doesn't help much.

Where's the 9mm for Nick, Nent? Have to say I like by big 11mm cables there, saves a lot of faffing around with rope protectors and the like.

Just wish somebody else would carry them!

exspelio
50.2% (Neutral)
Newbie

10 years ago

Its all to do with the surface area of rope in contact with the groove of the pulleys in the stop. A thinner rope will fit deeper into the groove so will have a larger contact area. :smartass:

Always remember, nature is in charge, get it wrong and it is you who suffers!.

gNick
50.2% (Neutral)
Newbie Topic Starter

10 years ago

The 9mm is for small holes in Nent, like the one I dropped on Sunday to see where it went, so they aren't too heavy - as ever a distinct shortage of willing string carriers. :)

Not too convinced about the not using rope protectors on 11mm - the sump we didn't drop the other day because of shortage of rope protectors would have scrapped an 11 just as quickly as a 9!

Don't look so embarrassed, it's a family trait...

Morlock
50.2% (Neutral)
Newbie

10 years ago

Theoretical drivel deleted.

royfellows
50.2% (Neutral)
Newbie

10 years ago

This is defying all my logic. I do have 2 stops, a worn one for older stiffer ropes and a new or nearly new one for new (ish) ropes. Have no experience with thin ropes, the stuff of bad dreams to me.

My avatar is a poor likeness.

RJV
50.2% (Neutral)
Newbie

10 years ago

"gNick" wrote:
Not too convinced about the not using rope protectors on 11mm - the sump we didn't drop the other day because of shortage of rope protectors would have scrapped an 11 just as quickly as a 9!

Oh I don't do away with them altogether, 11mm just gives you a lot more leeway.

Tony Blair
50.2% (Neutral)
Newbie

10 years ago

I went to the Carbis Bay Crew SRT day the other day. It was great.

Anyhow, I decided I would re-acquaint myself with a stop and it was like going out with an old girlfriend. It was better than I remembered it and I will be getting another. I made a point of trying it on various ropes from what appeared to be that arborists fat checky stuff to 9mm. It behaved almost identically on both, to the point that the only real difference was the ease of pulling rope through the wrong way.

My wife is the rack, she's much better than the old GF, the key point being flexibility. Unless you're fiddling on rope knitting, the best thing to use is a rack.

Rope too slow, take a bar out.

Rope too fast, lift your hand a bit.

Ergo:- Get a rack.

gNick
50.2% (Neutral)
Newbie Topic Starter

10 years ago

"Tony Blair" wrote:
Ergo:- Get a rack.

The frame bars for my new stainless steel rack are being made at the moment will hopefully be able to try the happy world of racks soon.

For what it's worth I'm going for a long micro so I can try more than 4 bars, I can always make the frame shorter if I don't need extra bars.

Don't look so embarrassed, it's a family trait...

Tamarmole
50.2% (Neutral)
Newbie

10 years ago

#10

"gNick" wrote:

"Tony Blair" wrote:
Ergo:- Get a rack.

The frame bars for my new stainless steel rack are being made at the moment will hopefully be able to try the happy world of racks soon.

For what it's worth I'm going for a long micro so I can try more than 4 bars, I can always make the frame shorter if I don't need extra bars.

Provided you have a hyper bar you don't need more than 4 bars. However if the spirit moves you No. 3 bar could also be a hyper bar (with the bollard pointing down) giving you in effect a six bar rack!

gNick
50.2% (Neutral)
Newbie Topic Starter

10 years ago

#11

Or I can add an extra bar and a hyperbar so I can have a 7 bar rack and spend hours getting down a 10m pitch 🙂

Don't look so embarrassed, it's a family trait...

gNick
50.2% (Neutral)
Newbie Topic Starter

10 years ago

#12

"Tony Blair" wrote:
It behaved almost identically on both, to the point that the only real difference was the ease of pulling rope through the wrong way

I knew it, I am suffering from an anomaly!

Don't look so embarrassed, it's a family trait...