Retrieval rope for 70m single-strand rappel

Most (all?) of the rappels in the Gunks can be done top-to-bottom with a single-strand rappel on a 70m rope. So for this convenience I'd like to get a retrieval cord to go with my 70m. I'll be using a system like this so the retrieval cord will never hold body weight--it will be used exclusively for pulling down the lead rope.

Lightweight and not bulky seem like priorities, since I'll have to carry this up climbs. I'd also like to not spend a ton of money, since it's a convenience cord, not a safety cord. I'm thinking something in the 5mm-6mm range. However, I've been having a hard time finding a 70m+ cord like this for <$100. Does anyone have any recommendations for cords that I should get, and where I should get it?

The best I've found from a reputable company is this.

If there is any rope drag when pulling the main cord, a 5 mm will be painful to your hands because it is so skinny. Consider a 6mm or greater pull cord, or just get twins. (I acknowledge this wasn't your question, but wanted to give some unsolicited advice!)

Imlay pull cord come highly recommended from the canyoneering folks, as it is more static than standard accessory cord, which makes a lot of difference on the ease of pull.  You can get 70m for ~$115 shipped.  Maybe get a bit more for rope stretch...

http://www.store.canyoneeringusa.com/component/rokecwid/?option=com_rokecwid&Itemid=&view=ecwid&ecwid_product_id=10914134#!/Imlay-6mm-Pull-Cord-static/p/10914134/category=0

Just got to the climbing shop and get the length you want cut of the spool.  I think I paid 40 cents per foot for 6mm accessory cord.  

Note:  6mm works fine, but this diameter is on the margin of too small.  A friend of mine bought 5mm.  It tangles super easy and cuts into the hands quite a bit when pulling.  YMMV

FrankPS wrote:

If there is any rope drag when pulling the main cord, a 5 mm will be painful to your hands because it is so skinny. Consider a 6mm or greater pull cord, or just get twins. (I acknowledge this wasn't your question, but wanted to give some unsolicited advice!)

Hm, that's good to know. I imagine I could solve this problem by using my belay/rappel gloves. However, I mainly use the gloves for catching falls when belaying the leader with an ATC, and since I've made the switch over to belaying the leader with the Click Up, I've been thinking of ditching the gloves entirely. I'll have to consider this a bit.

I'd like to make the leap to twin ropes because I'd definitely see a lot of benefit from them on wandering Gunks routes. But the main reason I haven't is social: I don't know anyone who climbs with them or knows how. I'm confident I could learn, but persuading other people to learn would be the hard part.

The skinnier the rope is, the more it will tangle. 70 meters is a lot of tangles. And as mentioned above, the harder it is to pull. You're probably better off:

1. Using a cheap rope of any somewhat normal diameter (~7mm)

2. Fixing a line to use for the day might be an option, depending on the area

3. Just rapping twice

If you want to go cheap, I have 60m of sterling 6mm cord in excellent condition I can ship you for $50.  Since it is just a pull line, you can always flemish bend in an additional 10m of cord. PM me if interested.  

David Kerkeslager wrote:

I'd like to make the leap to twin ropes because I'd definitely see a lot of benefit from them on wandering Gunks routes. But the main reason I haven't is social: I don't know anyone who climbs with them or knows how. I'm confident I could learn, but persuading other people to learn would be the hard part.

FYI, you'll want double ropes for wandering routes...not twins.  The distinction is subtle but might be appreciated (maybe not).