Touring - How many pounds in a cu inch??

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.

View Full Version : How many pounds in a cu inch??

Clarenza
05-12-08, 05:45 AM
I know this is a bit of "how long is a piece of string" question but has anyone figured out a typical ratio between the capacity of panniers (usually expressed in cubic inches or litres) and the weight of the stuff that will fit in them (in pounds or kilograms)? Or to put it another way, if four panniers have a capacity of say 65 litres / 4,000 cu" (like the Ortlieb Roller Plus set), what max weight would you expect their contents to be? If it makes any difference, I'm assuming the tent and sleeping bag will be on the top of the rack, not in the panniers.

staehpj1
05-12-08, 06:03 AM
That is widely variable depending on what you carry and how you pack it. I doubt that you can come up with a meaningful number.

If I had to guess I would say that 10 pounds per 1000 cubic inches (with some room left for daily groceries) was "normal" but as I have said there are too many variables for it to mean much. People manage to stuff twice that into the same space and others fill the same space with less.

RCordone
05-12-08, 06:15 AM
from the useless information dept:

If you fill the panniers full of water each liter of volume will weigh 2.2 Lbs. or about 140 lbs for your 65 liter panniers.

tmac-100
05-12-08, 06:20 AM
mass = density X volume.

So it depends. Why not try the brute force approach and amass (no pun ;-) ) all the types of things you want to carry, stuff the panniers full, and...... weigh them.

Otherwise your question is a useless exercise in futility

Good luck. Don't rupture yourself or your bicycle trip WILL be postponed.

iain.dalton
05-12-08, 06:50 AM
Depends on what you're carrying. For example, the Pink Lady (http://www.teamalameda.com/FlashBlog/?p=14) (apparently legendary in the Bay Area) would have a very different answer than some.

nun
05-12-08, 07:38 AM
I know this is a bit of "how long is a piece of string" question but has anyone figured out a typical ratio between the capacity of panniers (usually expressed in cubic inches or litres) and the weight of the stuff that will fit in them (in pounds or kilograms)? Or to put it another way, if four panniers have a capacity of say 65 litres / 4,000 cu" (like the Ortlieb Roller Plus set), what max weight would you expect their contents to be? If it makes any difference, I'm assuming the tent and sleeping bag will be on the top of the rack, not in the panniers.

I think an interesting question would be to ask the weight to volume ratio of different types of cycling
bags. Some panniers add a lot of weight to the bike even before you've put any gear in them.

Speedo
05-12-08, 08:14 AM
Depends on what you're carrying. For example, the Pink Lady (http://www.teamalameda.com/FlashBlog/?p=14) (apparently legendary in the Bay Area) would have a very different answer than some.

:lol: :lol:

Neat story!

Speedo

valygrl
05-12-08, 08:33 AM
I think an interesting question would be to ask the weight to volume ratio of different types of cycling
bags. Some panniers add a lot of weight to the bike even before you've put any gear in them.

Somebody did that for handlebar bags, I remember seeing a spreadsheet maybe 2 months ago. It was very interesting - large differences in weight ratio. I think Lone Peak 'won' and Arkel 'lost'

Bekologist
05-12-08, 09:42 AM
are you packing gold, or feathers?

some cheap panniers will blow out after two months of use hauling 10 pounds of stuff, ortliebs you can haul bricks regularily and not hurt the bags any...

a liter is about 60 Cu/In, if my memory serves me. roughly. a 30liter backpack is about 1,800 Cu/In. backpack capacity is often described in liters. works well for panniers

Think about panniers in how many 1 liter nalgene water bottles or gallons of milk they can hold...and a much more valuable gauge than weight.

my rule of thumb for weight is 5-8 pounds in each front bag, evenly weighted, and 10-15 in each of the back depending on clothing choices and food being carried. weight distribution is less important there.

and a general rule about panniers: except with the absolutely smallest panniers out there, you can make a bike pretty dang heavy pretty dang quick. pack lightly.

Clarenza
05-13-08, 03:57 AM
We won't be packing too many feathers and unfortunately the gold is in real short supply (pity that at ~ \$900/oz). We'll just be packing all the normal touring gear: clothes, camping gear, spares, etc, nothing unusual.

staehpj1, thanks for the ballpark figure of 10 pounds per 1000 cubic inches (that works out at just under 280 grams / litre.)

Bekologist, what panniers do you use, do you know their capacity? If they're similar to the Ortlieb Roller Plus, they're about 65 litres or 4,000 cu", and you pack 30 to 48 lbs in them -- sound about right? That's 7.5 to 12 lbs / 1,000 cu" (or 210 to 330 grams per litre) which brackets staehpj1's figure. If your typical load is 40lbs that's spot on his 10 pound figure.

So maybe this is a starting to look like a rule of thumb -- yes, yes, with all the caveats that it depends on the load, I got that already.

Bekologist
05-13-08, 07:15 AM
I use Ortlieb and have used both roller and packer models, front and back. currently favoring bikepacker classics in back, front rollers. I have been riding tours with less and less gear, applying the ultralight backcountry ethos to bike touring, and sometimes ride with around 20-25 pounds of very lightweight gear;(shelter weighs 1-3 pounds). panniers, food, water and fuel not included in that 20 lb figure.

I'd not worry too much about it. a set of panniers front and rear, particularily some Orts, and you are pretty much good to go.

Ken Wind
05-13-08, 08:08 AM
Depends on what you're carrying. For example, the Pink Lady (http://www.teamalameda.com/FlashBlog/?p=14) (apparently legendary in the Bay Area) would have a very different answer than some.

That is so cool. I hope I meet the pink lady one day.