whitelackington
New member
I see from caver's postings that many have now dropped down from 11mm /10mm to 9mm
are there any downsides to this?
are there any downsides to this?
S.R.T. rope diameters
- Thread starter whitelackington
- Start date
paul
Moderator
whitelackington said:
Genrally, you cam summarise the respective properties of SRT rope with resect to diameter alone and ignoring other factors/properties as:
Larger diameter = heavier, more expensive, less shock absorbancy, better abrasion restence, higher strength.
Smaller diamater = lighter, cheaper, more shock absorbancy, worse abrasion resistance, lower strength.
Next choose which properties you wish to prioritise and which you wish to compromise.
That's it in a nutshell.
M
MSD
Guest
As I see it, there are two basic concerns with thinner ropes:
a) Rope failure
b) Losing control while abseiling, due to less friction
Correct me if I am wrong, but I don't see any significant evidence from accident statistics that either of these concerns are justified. 9mm ropes are not snapping or a regular basis, nor are cavers hitting the deck more frequently. Conclusion: SRT techniques are sufficiently reliable that 9mm ropes are perfectly OK for general use by experienced cavers.
Other issues (bounce, cost, weight, general handling qualities, longevity) are not so important, pick whatever you like. I think 9mm ropes cost about the same over the long run. They cost less, but you have to retire/chop them with a rather more conservative attitude.
Mark
a) Rope failure
b) Losing control while abseiling, due to less friction
Correct me if I am wrong, but I don't see any significant evidence from accident statistics that either of these concerns are justified. 9mm ropes are not snapping or a regular basis, nor are cavers hitting the deck more frequently. Conclusion: SRT techniques are sufficiently reliable that 9mm ropes are perfectly OK for general use by experienced cavers.
Other issues (bounce, cost, weight, general handling qualities, longevity) are not so important, pick whatever you like. I think 9mm ropes cost about the same over the long run. They cost less, but you have to retire/chop them with a rather more conservative attitude.
Mark
Smaller diameter = the bags get heavier!
Ironic; but you can fit more in a bag if it's thin and flexible than if it's thick and cable - like. Overall tackle weight is down, butindividual load is often up as small teams can realistically tackle bigger caves. A few years back a pair of us bounced of a 300+m cave - only half a bag each, but each was jammed full of 8mm; essentially a solid lump of nylon, diversified by alloy...and boy, were those half bags heavy on the way out!
Ironic; but you can fit more in a bag if it's thin and flexible than if it's thick and cable - like. Overall tackle weight is down, butindividual load is often up as small teams can realistically tackle bigger caves. A few years back a pair of us bounced of a 300+m cave - only half a bag each, but each was jammed full of 8mm; essentially a solid lump of nylon, diversified by alloy...and boy, were those half bags heavy on the way out!
paul said:
A brilliant summary which leads me to using 10mm rope for club use (and for personal too actually, because it tends to be used in a very similar way to club rope).
Would people agree with me that knots are a bit harder to untie in smaller diameter rope? Given that I usually use 10mm and that I only use other stuff abroad on bigger trips that tend to have been used for longer periods of time. it's difficult for me to be certain ... but it's certainly my suspicion.
cap n chris
Well-known member
damian said:
Not my experience.
Obvious question: what knot(s) do you find difficult to untie?
cap n chris
Well-known member
Wet the rope.
Burt
New member
From experience, knots are generally harder to untie in smaller diameter ropes. If you want to see for yourself get a bit of 5mm and 10mm dia, put a fig 8 in the end and hang off them on your harness. The smaller rope will be a sod to untie. How much difference there is between a 9mm and 10mm is a moot point though.
If youve ever climbed on a double rope system with 8.5 or 9mm you'll also notice how much easier the smaller rope tangles, too!
If youve ever climbed on a double rope system with 8.5 or 9mm you'll also notice how much easier the smaller rope tangles, too!
LarryFatcat
Active member
There is also the issue of rope bounce when prussiking and control on abseils with smaller diameter ropes.
S
speleokip
Guest
hahahaha i find 9mm fat and generally use 8mm for push rope replacing it later with 10mm - team this up with a bunch of other super lightweight weight rigging tricks and you can carry a lot more push rope. BUT it aint commuter rope 2 different worlds entirely. The skinnier you go the less rock the rope can touch "period!" you can get away with some appalling rigging on a polyester 10mm but you have no chance on a nylon 8mm, it is subtle differences of choice at this gauge.
if you aren't a good rigger buy a fatter rope and go skinnier as you believe you can rig a rope totally free of the world and then when you step onto it you can truly test your belief in yourself cause few folk will step onto skinny rigging behind you or at least until you have proven it won't break. javascript:void(0);
Shocked
if you aren't a good rigger buy a fatter rope and go skinnier as you believe you can rig a rope totally free of the world and then when you step onto it you can truly test your belief in yourself cause few folk will step onto skinny rigging behind you or at least until you have proven it won't break. javascript:void(0);
Shocked
LarryFatcat
Active member
I prussiked up a 73m pitch in a Derbs mine a couple of weeks ago. Frankly the virtually new 10mm edelrid was more than bouncy enough and it looked way too thin.
On the other hand used a 4yr old 8mm on a small pitch last week and the control and stretch were fine.
On the other hand used a 4yr old 8mm on a small pitch last week and the control and stretch were fine.
