How many liters does a 70m 9.8 rope take up in a hiking backpack?

Oh ye’s of little faith.  Do you think I just spout off on these forums without being able to back the shit I spew?   Haha, well don’t answer that, but I do always leave myself an “out”.  In this case,  I did say “20 something” not 20L exactly.  

So, here’s the deal.  You tell me if I cheated or this is legit.   I took a BD speed zip 24L, a dozen draws, 1.8 liters water, 2 protein bars, a MicroPuff, BD harness, gri-gri, a San Pellegrino as beer stand in cuz I’m out, a pair of TC pros, a chalk bag I haven’t seen in years (only use for 12s and above), a BD vapor helmet, and an old 10.2 x60 (closest in volume, cuz I don’t own a 70, so shy by a few hundred cc)...

Results:  I didn’t even try and got it all in on just my “recon” attempt with rope just coiled as I pulled it off my wall.  Totally confident that with finer tuned packing and flaking, I could add more gear.  If I used my Patagonia Ascensionist 30L, I could bivy inside. No question I could go full trad with a 35 as that’s std.  

also, FWIW, I have ridden my BMW GS 650 to the crag with said backpack with no issues. I do actually keep it below 80 with the pack on though, but otherwise it’s better that riding two up.

I mean...yes that’s impressive, but can I see a picture of the pack label, you know, just to make sure it’s not a 35L pack? And you are missing 30 ft of rope, but I guess I’ll give it a pass for being a 10.2 and you did throw in a helmet and a jacket. So bravo.

I didnt want to carry my BD creek on a plane last week, so I used a 30 something L BD ski pack at Red Rock. I struggled to get everything in...now I need to go home and practice packing.

Wow, no trust...lol

Ok, suitably impressed. You inspired me to try it. Here is a 9.8 60m rope (my only other rope is an 80), harness, shoes, chalk bag, two 1L bottles, 12 draws and two alpines, Grigri with belay gloves, and helmet. It all fit very snugly into a Cirque 35. This is a ski pack with no headpiece, so the helmet poked out the top a bit. I might have been able to fit a couple of bar,  but not likely a real lunch. I maybe could have stuffed in a light jacket. I doubt all that would have fit with a 70m rope. Definitely not adding a rack in here and I’m not sure how this would all fit in a pack supposedly 10L smaller. If I had along approach I’d consider using this, but for cragging, I’ll stick with my Creek 50.

Couldn’t quite fit the 2nd Evian in there, but maybe if I had a 70m rope instead.

Thank you all for the great responses and the photographed demonstrations. I really appreciate it.

Levi Xwrote:

I'm curious how you got this number? 

L*pi/4*D^2, while ignoring all void fractions, or just having the alcohol tolerance of a 105 pound coed.  And I don't think he'd fail to account for the void fractions.

Just buy ten bags to find out which one (or three) are your favorite. Maybe I’m the only one

And then return the rest to REI after trying them out a few times, right?

I would like to dedicate this post to my climbing partner who told me I needed a bigger bag.

The water bottle goes on the outside because there’s slots for it and you bet I will use them. 

35 liters advertised includes all the pockets.  My wife carries a deuter 34.  I carry a Gregory 40 which replaced my Deuter 42.  

First, yes a 70 meter, 12 quick draws, biners, cords, shoes and harness can fit in a 35.  Helmet may need to hang or ride on the sack.

Second, test the sack with your gear and return it if it does not work. The Gregory 40 carries more than the Deuter 42  (my wife disagrees).

Third, not a liters are equal. Those liters in the belt pouches are useless. 

I’d say a 70m 9.8mm would take up just about 15L of space. Maybe slightly under. I have a 70m 10mm rope and I can stuff it into my 15L BD Rock Blitz. Takes up pretty much the entire bag. 

I have one of those little orange Metolius haul purses. It's generally big enough for a pair of shoes and harness. Or half a bag of ice and a six pack.

I've flown with it many times, it's smaller than a carry on and counts as a personal item. A 70 fits in there if I use my foot.

FWIW I think the bd speed 45 is my favorite pack for all-around climbing. Sure, you can fit a whole sport climbing day into a 35, but it sits better in a larger pack.

I carry lots of water (two 1.5L nalgene) and prefer to have it inside the pack. Speed 45 has room for it all while being comfortable to climb in with 20-30L in it (and not flapping around like some other 45L packs that I've used). I think it would be as good on a bike as it is on an easy 5th scramble.

Every pack is different and I think size measured in liters is only one factor.

damn, i need some serious packing lessons.  it seems like no matter how little i am packing, my pack is always pretty close to full.  I can't believe mark fit that whale of a rope into the speed 24, much less the other stuff.

The Fish Bolt Bag, fit all my stuff except my helmet.  Russ makes quality stuff, it’s much bigger on the inside than it seems.

Kevin Mokracekwrote:

The Fish Bolt Bag, fit all my stuff except my helmet.  Russ makes quality stuff, it’s much bigger on the inside than it seems.

Yeah I think Hermione Granger has one of those. Much bigger on the inside than it looks on the outside.

i was just about to accuse him of witchcraft.

Ry Cwrote:

The water bottle goes on the outside because there’s slots for it and you bet I will use them. 

Please don't do this when climbing while wearing the pack. Water bottles easily become 1-2 pound death missiles as the elastic mesh is far from secure. Similar problems arise when using the plastic lid strap of a nalgene as a way to clip a bottle (the strap breaks easily). I've seen three instances of this, 2 near misses and 1 seriously messed up collarbone. (Not so much directed at you specifically as a general PSA for anyone else who comes along).

Derek DeBruinwrote:

Please don't do this when climbing while wearing the pack. Water bottles easily become 1-2 pound death missiles as the elastic mesh is far from secure. Similar problems arise when using the plastic lid strap of a nalgene as a way to clip a bottle (the strap breaks easily). I've seen three instances of this, 2 near misses and 1 seriously messed up collarbone. (Not so much directed at you specifically as a general PSA for anyone else who comes along).

The water bottle usually fits in the bag nicely once you take out the rope, rack, harness, helmet, and shoes.