UKC

So I am off to Lundy in a few weeks, and am planning on getting a 100m abseil rope (at least partly just because I can, plus you can then top-rope 40m routes from the ground if you are so inclined...)

Ignoring my motivations, my choices are:
Mammut Performance Static Red 9mm £92, 51g/m (5.1kg)
Mammut Performance Static Gold 10mm £102, 66g/m (6.6kg)
Mammut Performance Static (various) 11mm £115, 75g/m (7.5kg)

The 9mm is a type B rope, the others are type A ropes. All the ropes are also available by the metre for the same price per metre, or in 200m rolls for £170, £190 or £216 respectively.

The question is which is the best diameter - I'm not going to put this rope through particularly use so should I save both my wallet and my back and get the cheap, light 9mm rope? Or is this too thin/easily cut/unfashionable, and I should play it safe, spend the money and lug in the heavy 11mm rope?

(also I suspect that the 9mm rope will not lock up in my Megajul, but it will still work - I will just have to use a prussik like normal, while the 11mm rope may not even fit...)

PS anyone want halves on a 200m roll if that works out cheaper after the cost of postage?

In reply to andrewmcleod:

From 'Alpine Caving Techniques':
Once used primarily for smaller teams, 9-mm ropes are now the norm for most caving clubs, and are also used regularly in French Caving School training sessions, and this is one organisation that is serious about safety

Those Mammut Performance Statics have strengths of:
9mm = 22kN
10mm = 28kN
11mm = 35kN

Keeping in mind caving is a lot of abseiling/rope ascending, I'd personally go with probably the 9mm, maybe the 10mm if I was feeling paranoid.

I'd not go with 11mm, aside from the weight, I find thick statics harder to work with.
(Caving club was fan of thick ropes, curiously they retired them not because they were suspected weak or showed damage - but because they got too stiff to work with).

In reply to andrewmcleod:

I would just have 50m of 10mm. Any longer is probably a waste, unless you are really desperate to bottom rope stuff. 100m of rope is quite heavy and bulky to carry, on top of a rack and climbing rope etc.

In reply to needvert:

it's a little different for caving though, as you are far more likely to ascend them, but also volume and ease of dragging rope through passages is more critical, so weight and volume are of greater significance than in climbing. But, with all statics, they aren't static and will stretch a little. A 9 will stretch a little more than a 10, so there is a trade off if you have to ascend a long way.

I always find 10 is good mid point, not to bouncy, not too bulk or heavy, easier than a 9 for getting knots out of.

In reply to needvert:

thanks, sounds like the 9mm should be OK then (will be careful with rope protectors etc)

In reply to summo:


But not, I am told, at Lundy, where a 100m ab rope is useful.

In reply to andrewmcleod:

80m is OK for Lundy. less than that is a bit more restrictive.

To the OP, personally I find 9mm just a bit thin to grip for a long abseil. Not sure how much opportunity you have to try before you buy ?

In reply to andrewmcleod:


if you want to drag 100m around for years, just so you have some spare when you go to Lundy that's fine by me.

I've managed at Lundy with normal ropes, it's only certain crags and there are work-arounds, especially if you go as 2 pairs and have two 50m ab ropes with you in total.

In reply to andrewmcleod: If you are anywhere near Oxford before you go, I have a 100m abseil rope sitting around that I'd be happy to consider selling (or renting out).

In reply to The Ex-Engineer:

Too late I am afraid (bought it this morning)! But thanks for the offer...

In reply to andrewmcleod:

Length is up to you but I'd recommend beal unicore 8.5mm. V light and utterly bombproof. Used caving lots and no sign of wear!

In reply to andrewmcleod:

Mega Jul works on 7.8mm - 10.5mm, holds 9mm falls as easy as it holds 10mm ones.

In reply to Removed User:

Failed to mention I meant for abseiling - my Megajul holds my ~70kg (over)weight happily on either a pair of 8.5mm halves or a 10.2mm single, but doesn't quite hold my weight on a single (new) 8.5mm half (you slowly slide down the rope if you don't lock it off manually). I suspect it will on a stiff 9mm static though...

In reply to andrewmcleod:
Just remember if you plan on using a shunt or something similar to work routes, 9mm single maybe too small a diameter. At least with a 100 meter you can double up though!

Cheers

In reply to andrewmcleod:

I use it in non-locking mode for abseiling if I'm on 2 lines, if it's a single line I usually stick with a grigri2. Spoiled for choice since I had a grigri2 before I got the megajul!