Cavechat.org

We have already weeded out UHMWPE rope. That leaves us with nylon, polyester, and combinations thereof. Let's start with the assumption that all static vertical ropes get the necessary rope pads.

It seems like most vertical cavers try to use 10mm-12mm ropes whenever possible. If the rope has a tough "canyoneering" sheath, then that is a plus. Then on some occasions, a cave trip leader might decide to use a 9mm rope, but hardly anybody moves down very far into what we could call a single rope of a two-rope setup. Who uses 8mm? I'm guessing that nobody uses 8mm or thinner.

One guy said that he used 11mm or 12mm if he didn't have to use a very long length or if he did not have to carry that weight very far. He said that he was inclined to use 8mm-9mm rope when he did have a long carry-in.

As you might tell, I am shopping around for another new rope, probably around 200 feet. I regularly use a 3/8ths inch rope and prior to that was a tough 9mm rope.

11mm is considered standard and PMI Pit rope and its equivalents are the tough as nails products that are most popular. Highline makes an excellent and very cheap 11mm rope. Atwood makes a good cheap polyester 7/16".

I use 8mm often enough simply because I have a length. It is very nice to carry and work with and less nice to climb on. There is more bounce and there are more feeding issues when the rope is slimed. 8mm is harder to find, often more expensive, and less versatile, so I probably won't buy more.

I have a friend who says he did Fantastic Pit with either 8 or 9 mm. As long as the rope is hanging free, and not subject to abrasion, it should be plenty strong enough to support the average caver. Not sure if I would use it to climb tandem.
The chief benefit of smaller rope is that it weighs a bit less. That doesn't matter much until you get up to really long lengths.

Trogman

A fatter rope is likely to last longer in years, if that is a factor.

In my experience, 11 mm is generally too fat to move easily on once you get it dirtyy. This is of course related to the fact that I cave on a stop. 9.5 mm is my happy compromise, although I have done plenty of drops on 8 mm when I ran out of rope, or on expedition. Often related...

Where do I start?

RAPPELLING: the biggest variable is rappelling is the rope. I don't mean what the rope construction material is, I don't mean how tight the sheath is, I don't mean how thick the rope is. (I'm limiting this discussion to 1/2" aka 12.5mm to 7/16" aka 9mm). Even the same rope will vary. It may have gone caving the day before and be gritty. Even if it didn't cave before, the top may be dry and the bottom get's some water spray and it's wet. New rope is fast, Skinny rope is fast, Wet rope is fast, Old rope is slow, Dirty rope is really slow, Fat rope is slower, But how do you know where on each drop the rope is now dirty, wet, or dry? That's why racks are cool, you can vary your friction as you go.

ROPE MATERIAL:
Almost the entire caving community in the US is using Nylon sheath and Nylon core. It works and will continue for years to be the standard. However I do not use nylon, here's why. 1st it stretches more than Polyester. For every step you take when you climb the first part of that stroke removes stretch the next part move you up. 2nd Poloyester adsorbs less water. About 1/2 of my cave trips the water adsordbsion is not an issue. But almost all of the trips where it's water is not an issue, stamina is also not an issue. The extra weight of a wet rope only counts when your going deep, far, or long.

DIAMETER:
Diameter of rope is two different discussions, rope strength, and rope weight.
The standard for the US caving community is 7/16" (11mm). I don't buy 11mm, here's why.
I'm Fire Department. Bear with me here, National Fire Protection Agency !500 standard lists the minimum breaking strength for general purpose (2 person load rope) to be 9,000 lbs breaking strength. Although not official many people interperet this standard as being 300 lbs per FF (with turn out gear and SCBA) plus another FF being rescued and if you do the math that's a 15 to 1 safety factor over working load.
Cavers with gear and pack pretty much max out at 250 lbs.

DO YOU PLAN ON TANDEM CLIMBING THIS ROPE: (2 cavers on rope at the same time)
I don't consider tandem climbing anything less than 250' and it's rare that it's less than 400 when I do.
9mm poly or nylon will meet a 15 to 1 safety factor for a single caver so why do so many people buy a 250' or less rope that's fatter than 9mm?
If i was buying a rope less than 250' it would be no fatter than 10mm.

ROPE STAMINA:
Several Rope manufacturers do not support or recommend a rope being older than 10 years. I do not know of anyone who "wore out" a rope. I know of many instances where a rope pad placement was not maintained, or completed due to miss-communication, or other circumstances that lead to the rope sheath being damaged and the rope was cut shorter to remove the bad spot. If you know anyone who claims that they wore out a rope I would greatly appreciate a brief discussion with that person.

CANYONEERING:
Canyoneering is caving, except for: a big hike to get there, It's only rapells there's no climbing rope, there's no crawling, no mud, no stoop walks, great lighting (aka photos). So what's used for canyoneering rope is 9.5 Polyester because they don't want stretch when the do a pull down and they don't want water adsordbsion. The standard length is 200' (you usually bring 2-200' for the pull down).
I believe 10mm Polyester may be a liitle bit of overkill as far as strength goes but I'm ok with tandenming 10mm because if both caver's equal 450 lbs I've still got a 13.5 safety factor. (That's pretty dam close to the 15 to 1 that NFPA requires).

CaverCarl
See you at the CaveIn

What are the best vendors for modern static rope these days? Let's assume that we are talking about 10mm or 11mm.

I've purchased rope from On Rope 1, Karst Sports, OmniPro, and maybe another. Amazon offers a lot of rope, but many of them are no-name Chinese manufacturers with shaky specifications.

I neglected to mention Inner Mountain Outfitters.

You've listed the best sources. As you ascend out of a pit and watch your El Cheapo rope fray, it's too late to go back and get a good one. But, hey, your heirs will enjoy spending the $25 you saved on a no-name rope....

I never buy El Cheapo. Instead, I've looked at Shanghai Home Depot.

If you are trying to decide about what kind of rope to use.......
The simple thing to do is, use what most of the others use.
If you want to make your own decision, first decide what characteristics, are most important to you.
I've decided that low stretch, for easier climbing is important.
I also like lighter weight.
Less water adsorption means less weight. Canyoneering ropes take this into account.

Should all rope lengths be the same diameter?
Lighter weight is easy to achieve if you go with thinner, however, will you be using it to tandem climb? In my experience usually only over 200' drops are worth the time saved by two cavers climbing together.
Perhaps only ropes over 200' long, need to have the strength for two to climb tandem.

I like 10mm Polyester core, Polyester sheath.

I recently purchased a 9mm PMI EZ bend that is 65' long, primarily for ridgewalking. The weight savings is what drove me to get it, and so far I am happy with it. In fact, I am considering getting a 100' piece of it. The caveats are:
1. It must be padded a little more carefully than 11mm. That being said, any rope diameter should be padded carefully, as a sharp enough edge will cut a weighted rope no matter what the diameter.
2. It is rather fast, especially with my long frame mini-rack. With standard 11mm, I often do not use the hyperbar. With this stuff, use of the hyperbar is a MUST. Even then, it is pretty quick.

Trogman

My preferences:
10-11mm on the long drops ...400+ (mainly due to the bounce factor) especially when tandem ascending.
8-9mm for most all general purpose vertical caving
My favorite is 9.2mm Imlay Canyonero rope. Lightweight, very well made, ascends as good as my PMI pit rope. I do a fair amount of canyoning and have a good inventory of the skinny ropes. They certainly have changed my mind from the traditional "pit rope for all drops" mentality.

Padding is key. Was out in ZNP this past fall and furnished the rope (9mm) for a first descent canyon with an 800+' final rappel. Saw one place that should have been padded (in retrospect) but did not pad it. The picture attached is the core shot that occurred on the final rappel. 6 rappels on this brand new rope - had to be cut - now a 705' rope. Sandstone/limestone out there can be brutal on rope. Be aware out there!