Why doesn't someone build a UL BPing chair…Entrepreneur needed!

How’s about

http://www.litesmith.com/qwikback-ul-chair/

I think that litesmith chair looks cool, but can you lean back hard on it?  I take leaning back seriously and would worry about those poles schnappin

re: LiteSmith QuikBack UL Chair…

Now we are getting somewhere…this looks like a significant step forward in the ground-sitting, back prop category of “chair”.  The weight is certainly attractive, and I bet this will be a good choice for a certain population.

For me, I’m concerned with how comfortable that narrow little top would be when leaning back?  Seems likely that it would dig into my shoulder blades. And while I hate to seem totally negative, IMO a back prop that requires sitting on the ground is not a true chair.  I want 12″ min. off the ground and back support as wide as my shoulders.

If anyone has tried that Quikback Chair, I’d love to read a review.  I almost always carry a chair on the trail, since I usually do a lot of reading and writing.  My go to right now is an Alite Mayfly, amazing chair, but mighty heavy.

If one leans forward does it fall over is my question.

“Does anyone see a way to make something like this using an external frame (a la Helios) with carbon fiber tubes? I’ve given it only a little bit of thought and I don’t, but I would be delighted to be surprised!”

I have some initial ideas based partially on working on my E.F. pack. I sprayed expanding foam into the Easton Carbon fiber tubes, which added noticeable stiffness to them and i theorize, some impact resistance.

But i haven’t given a UL chair much thought, due to lack of interest so far.  Seat material could be a composite of very light weight cuben sandwiched in between some lightweight robic nylon.  With the cuben providing tensile strength and robic abrasion and general wear resistance.

I wonder what the weight would be if you took the basic Mayfly design, used a carbon fiber frame, and material from a hammock?

Jim C,

I’ve thought the exact same thing. I like the idea of the Litesmith chair but I’m afraid it wouldn’t be relaxing. Any move you make will compromise the support and most likely cause the chair to “collapse.” I’d love to see Litesmith develop a chair that is basically a Chair One but like Jim C mentioned with carbon fiber and lighter fabric.

I’d love to see Litesmith develop a chair that is basically a Chair One but like Jim C mentioned with carbon fiber and lighter fabric

I love the Chair One…it’s pretty much spot on in terms of width, height and comfort. It’s only real downfall, IMO, is it’s weight. I still carry it on some trips tho.

I’ve thought a lot about rebuilding it with (much) lighter shock cord and CF tubing, retaining the stock seat. This seems like the most achievable DIY modification.  My concern is that the CF won’t survive the bending loads like the AL tubing does.  At 215 lb, the Chair One is pretty “bouncy” when I use it, and that seems to be all down to the flex of the AL tubing. I’m certain that flex is what allows the chair to survive.

Purchasing the required amount of CF tubing would not be cheap and the notion of one of them splintering while seated in the chair evokes nightmarish thoughts of hideous puncture wounds.

I have a couple of the G4Free chairs (almost identical to Chair One) and the tubes are odd custom sizes that fit neither Metric nor Imperial standard units.

So even as an experiment it would be a royal PITA to substitute CF for Al, and I don’t think a 1mm wall thickness for CF tubes would suffice, and CF tubes with enough wall thickness to do the job would probably weigh as much as Al.

The ultimate solution might be a combination of air chambers, CF rods/tubes and aramid strings/cords.

This would be an interesting project for one of those university engineering contests.

I was thinking the same thing re: the required CF tubing wall thickness negating any weight savings. I had considered deconstructing the Chair One an, weighing an AL segment and calculating if there would be any savings, but I guess I’m too lazy for that :)

I hope some enterprising soul takes up this design challenge. The Chair One is such a nice design…just too heavy to always pack.

Edit: Holy Moly there are a lot of (Chinese) clones of the Chair One!!!

Of course, the very lightest backpacking chair weighs zero grams. Works well.

I’ve been using Roger’s Zero Gram chair for over 50 years. I wonder what the cumulative weight savings has been.

I wonder what the cumulative weight savings has been.

Ah, trick question. :^) I know what you mean, but…

If your theoretical, un-carried chair weighed one pound, the cumulative weight savings is always one pound.

However, cumulative reduced energy expenditure could be estimated; stepping up one foot of elevation with a one pound chair would require one foot/pound of energy (for the chair portion of the load). So if you climbed a 1200 foot hill with this chair, you would have spent 1200 foot-pounds of energy to move that chair. There’s a lot more to it, of course, but that’s the starting point.

Alas, I am an armchair engineer and now await the dismantling of my explanation by a real engineer.

Got one one and it works well….as long as you can find a few branches.

For Bob: I’m a biologist, not an engineer, but I can tell you that we would use an energy unit you’re familiar with instead of footpounds for human energy saved: the large calorie. If you wanted to sound fancy you could call it a kilo joule.

Physics is out of my league… but wouldn’t footpounds be a force measure?

Physics is out of my league… but wouldn’t footpounds be a force measure?

One pound force over one foot distance: that’s a unit of energy.

Cheers

Ah, thanks Roger. The amount of energy required to raise one pound one foot. Far afield from a chair, apologies…

Scott,

Actually there is a conversion factor for ft-lb to kcal and I calculated that it would take only 0.38 kcal (a kcal being 1 standard dietary calorie) to carry that chair up the 1200 foot hill.

I think I’m going to start carrying a chair!

NOT! lol

Zero Gram Chair :-)

Hi Nick

Just so. This is after all BPL: the home of ultra-light and super-ultralight backpacking.

Cheers

While thinking about where you carry the weight having an impact on the energy burned I stumbled on two pieces of carbon fiber or aluminum  many of us already carry: stays in a backpacking frame or trekking poles. Trekking poles probably a no go for most as they might be dual use already for a shelter, but the stays… the thermarest and StS air chairs use poles that maybe could be replaced what you’re already carrying… assuming you have a pack where they are easily removed.

JCH, the Easton CF tent tubes/poles are designed to have a little more flex/give than a lot of other CF tubes out there.

I found that putting expanding foam in them, noticeably increased the stiffness.  It would be a good combo for such an application, because it would survive side flexing better than most CF tubes out there.  The inner foam core probably absorbs some of the flex stress, besides increasing stiffness.

I’m NOT a trained/educated physicist or an engineer, so i can’t say the above with any certainty.  I do know that when trying to bend the CF poles that became part of my external frame for a pack, when doing so by hand (i’m fairly strong for my size and conditioning), i didn’t feel like they would snap or crack anytime soon.

However, foam + CF probably equals the weight of similar sized tubing made out of Al, so maybe it’s a moot point.

Ryan Jordan packs a chair…

re: Nick’s Zero Gram Chair – I’m seriously jealous that he can still do that.

re: Justin’s foam filled tubes – If we can’t realize a significant reduction in weight, say >30%, then I just don’t see how the cost and effort of the modification are justified.

re: RJ packs a chair – Well…If Ryan does it then it MUST be kosher.

Ryan Jordan packs a chair…

I have been able to figure out how to backpack without emulating Jardine, Jordan, Skurka, et al. Not that they don’t have useful ideas, but they aren’t the final authority. I was backpacking long before any of them and was using such lightweight items such as tarps and single wall mids long before they enerered the public eye.