Sierra Designs Tensegrity 2 Elite

First, I heartily applaud SD and M. Glavin's initiative and engagement re: revealing/discussing their new products. I cannot imagine how anyone could fault the manner in which SDs products are being developed and presented…so much information being provided…amazing. The videos of wind testing are fascinating and, as others have said, I wish all manufacturers would (have the guts to) provide that information.

Next, as anyone who have ever designed anything knows, design is all about compromise. Whether a product "works" for an individual, or in a particular situation, comes down to how well the designer's choices align with the user's needs and expectations.
I am certain there are people for whom the Tensegrity will be the perfect choice. I look forward to hearing why that is so. I am equally interested in hearing from those for whom the Tensegrity's design choices do not work, and why. I have posted accolades and criticisms many times and the responses have shown that respectful, thoughtful comment is welcome here. I do not consider thoughtful, honest comments derisive or negative, but rather healthy discourse. Cogent comment has many times prompted me to change my mind or last least change the way I think about something.

Lastly, I am struck by how boring life, backpacking, and yes this forum, would be without all of the "Lively debate". Imagine not having access to R. Nisely's research, or R. Caffin's stove expertise, or J. Abela's in-depth analysis, or the wisdom of all the other experts on this list…that's not a forum I would want to frequent.

John:

Yes, everything is bolted to a steel floor.

Note that "stress on the stakes" will simply be a factor of how much fabric area is placed into the wind, and how many stakes there are. I don't think that "buttoning up the design" (though I admit I am not exactly sure what you mean by that) would have any affect on the stakes.

Note: Having the stakes be the failure point is the ideal scenario. In most shelters, the body collapses way in advance of stressing the stake points.

Come to think of it, I just got the wind tunnel results for the convert (a traditional, "buttoned up", 4 season design) that everyone would assume is "bomber". I'll pull that video and show you why that is likely (I have not looked at it yet) the case…….

Just looked at it. It is the case. Standby for additional video…..

Yes, the stakes should be the failure point of a tent. In most trekking-pole supported shelters, I would expect this to be the case.

This is a crude side-drawing to illustrate what I meant:

If there was a vestibule added to the side of the tent, it would transfer more of the wind load to the trekking pole (because now the wind load is compressive) and reduce the upward load on the stake (it would also give you a place to cook out of the wind). I guess this can be overcome in the Tensegrity by having extremely good stake-outs on the ridgeline guylines.

Edit: this is probably not an issue most of the time. I've almost talked myself into trying one out, but I think I still prefer my pyramid tarps

The wind tunnel tests are great and more than most (all?) cottage manufactures can do (I'm assuming that wind tunnels are hard to come by and expensive to rent time in).

What I would want to know is how much pressure is on the stakes? That obviously makes a huge difference in how well a shelter will hold up in wind. It would seem easy enough to me to test, but then I've never done any of that kind of testing. ;^) Easy for me to say!

Larry,

See Ryan;s post at http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=58096&startat=40

I don't recall reading any follow up by Ryan. I, for one, would be extremely interested in follow up by anyone unbiased to test the most popular existing UL shelters to compare/contrast with the new designs by SD.

I hear you, John. Skurka and I have been having the exact same discussion regarding "angles of exposure" to wind. And I am glad you drew this awesome simple drawing. Based on what I have seen in the tunnel, I am confident that your top design would be stronger in the wind. I know that sounds crazy, because the top design will "catch" the wind and the bottom design will "shed" the wind, so it is reasonable to assume the bottom design would be stronger in the wind. But tunnel testing shows a different story:

1. Assuming both wall panels were the same size (your "button up" wall is slightly longer in the drawing than the dotted line "inverted" wall), the wind force on both doors would be identical. A simple function of measured area presented to the wind.

2. the "buttoned up" wall would lose volume at nearly the same rate as the "inverted" wall, based purely on their size. If this were vestibule, it may not reduce interior volume (like Tensegrity from the end), in the case of Tensegrity from the side, it does. But the wind force on the panels themselves would be identical, realizing the "spill" patch of the wind would have some affect.

3 But the notion that the "buttoned up" design would "shed" wind, while the "inverted" wall would "catch" wind gives a false impression on wind strength. In fact what happens is that the "buttoned up" wall will get pushed DOWN on the top of the tent, while the inverted wall will push UP on the top of the tent. So it is true that the "buttoned up" will shed, and the inverted will "catch", but counter-intuitively, "catching" increases the wind strength. If you want your tent to be strong in the wind, you want it to blow UP. Blowing down is failure.

Look at the video of the tarp side of Tensegrity. That sloped panel blows DOWN. But when it blows down, also pulls OUT on the top seam, tensioning it more, and strengthening the pitch. The panel itself loses volume, but holds tension and is obviously very strong. (Note: high quality tent fabrics will RARELY fail (rip) unless you introduce extreme flapping somewhere. Tents almost always fail from pole failure.) On many b

OK. Now I really am going to do this video because this is hard to discuss in writing…. more later…..

So, if I had it pitched with the awning up, could I enter/exit through the front? Or is there not enough zipper?

You can definitely enter/exit through the front, which is pretty cool.

Thanks, my image search came up empty.

Would be interesting to have load cells on the guy lines while testing. Could instrument the poles as well.

I don't know what your testing budget is, but if I were paying for wind tunnel time I'd want to get the most out of it.

For a few grand you could get some miniature load cells, power supply, a labjack, a few other bits and get a ton of potentially insightful data. Something like http://www.omega.com/pptst/LC201.html for tension on the lines, and there are similar models that you could use for compression on the poles.

The REI "Flagship" store in Seattle has the Tensegrity 2 FL and were willing to set it up for me with their velcro "stakes". I like the concept but one thing that keeps me from getting one is the interior height and how quickly it gets lower from front to back. We may have not had the pitch right and real stakes would have allowed a tighter pitch. But for me a taller back hoop and maybe a taller front would help this old man move around better in the tent without touching the fly.

Question:

Anybody who's actually used one on these things have anything to say about it?

I know it's still "pre-season" (at least here in Vermont), but it's also big-box store (REI, Backcountry, EMS…) sale time and I'm surprised Google and Youtube searches still come up empty.

Thanks!

Oh, and by the way- thanks to M Glavin for his posts, esp. the wind-tunnel tests. Those were impressive, considering that there wasn't anyone or anything in the tent giving it stability. And why are so many of us so vitriolic toward him and SD? AFAIK they're just trying to innovate and willing to take a few chances here and there…

The snow on the ground melted today, so I had a chance to set mine up in my backyard. I'll share my initial impression, but I can't wait to try it out for real.

This is my first freestanding tent and my first sil nylon tent. Setup is a bit tricky since the tent doesn't take shape until you are done setting it up. I couldn't figure out the optimal stake placement relative to the tent, but it was close enough on the first try once I tightened the cords. Installing the pole was difficult because the grommets are fixed, so it takes quite a bit of force to get the pole in. I left the pole in overnight, and the fabric didn't seem to stretch at all, which is good. But it seems to put a lot of stress on the fabric. It looks like it's pulling apart the seam where one of the corner reinforcement panels is stitched on, and stressing the bug netting. I think I'll reinforce the reinforcement panel with some repair tape to make sure it lasts and to keep it waterproof. I used ski poles since one of my hiking poles is out of commission, and the fixed length of the pole wasn't a problem, but I did have to stretch the fabric a bit to get it over the pole. The ends of my ski poles are slightly too big to fit in the grommets, so I had to loop the end of the grommet webbing around them. With regular trekking poles it would be easier to install the poles since the tips would fit in the grommets. If you use rubber pole tips you'll have to come up with a different way to secure the poles, or maybe SD could make an adapter for those. The garage went up easily, and this end of the tent is huge! It could be tricky to find a suitable site for it sometimes. Looking at pictures of it, I was a bit worried about stuff under the awning getting wet if it rains, but I don't think it will be an issue at all.

I set it up on top of my old 3 person tent footprint to keep it dry, and because I don't trust the relatively thin floor yet. It's significantly longer, but obviously not as wide, as my old tent (Stoic ARX XL3). The inside is spacious, and the shoulder room and head room on the head side of the tent are great. I'm 6' tall, and there is plenty of length inside. The head and foot walls are vertical (or nearly vertical), so wet sleeping bags shouldn't be a problem. I think someone asked if you can sit up from a sleeping position and not hit your head on the roof, and I can't. I have to scoot towards the head side just a bit, but I don't think it is much of an issue for the livability of the tent. I usually scoot up to get out of my sleeping bag, anyway.

I'm a fan of the zipper panels that close off the side vent. My old 4-person department store tent had those on all the windows since it had no rain fly, and it was nice to be able to adjust ventilation and privacy from inside the tent. I really wish the garage door had a panel that could close it off. I know this tent is all about ventilation, but I live in Colorado where it's dry, windy, and cold most nights. I often would prefer to trade some dampness for reduced wind and a little more warmth inside the tent. My other 3 season tent has mesh all the way around, but the full fly can be staked almost all the way to the ground, and that keeps some of the wind out (since the wind speed is lowest near the ground). I might rig up something myself to seal off the garage door.

I look forward to seeing how this will hold up in the wind. I noticed that in the wind tunnel test video they used the extra guylines in addition to the garage tarp. That's kind of cheating because one of the features of the design is that there are no guylines in front of the doors. I've camped in some strong wind, but I don't have a good way to measure wind speed while camping and compare it to the wind tunnel tests. The stakes that came with the tent are about 6.25 inches long, which is a bit shorter than my other stakes, which are 7 inches for generic aluminum Y stakes, and 7.5 inches for MSR Y stakes. I'll compare the weight at some point and decide which ones to bring, but it seems like this tent puts a lot of force on the stakes.

Overall, I like the space and configuration of this tent. The unique design is the reason I bought it. I think I'll be happy with it if it's not too drafty inside, and if it holds up to the wind and to normal use. It could use a few minor improvements to address the issues I described, but overall it's a well thought out design.

"And why are so many of us so vitriolic " i think it is really just healthy skepticism. Many posts come across as curt. Such is the inter webs. And let's face it SD has had many a mediocre product in the past. Some less than mediocre touted as the best thing since sliced bread.

Noticed that they quietly changed the cuffs on the Pack Trench coat so the would actually keep the water out if you raised your arm.

I like the new Sierra Designs stuff. If I had an extra $400 laying around I would get one of these. I already have some heavier tents that my two sons and I will be taking to Philmont this summer. If I didn't have to buy some other gear X3 this would definitely be something I'd like to take on my trek.

" 'And why are so many of us so vitriolic' i think it is really just healthy skepticism. Many posts come across as curt. Such is the inter webs. And let's face it SD has had many a mediocre product in the past. Some less than mediocre touted as the best thing since sliced bread."

Ken's probably right. SD has nothing I am interested in at this point in time. However, a long time ago, I had a lot of SD gear — back when they were an innovative company.

So I am watching with interest. I hope Michael and Andrew come up with some great products for our niche. It has been refreshing to see Michael come to BPL and share his ideas and ask for feedback.

people like to complain about REI not having UL stuff (or any high end stuff really)… if SD keeps hitting the drawing board for a few years that could change. I'll keep being interested… but probably won't buy anything for a while.

Matt V,
Thank you for posting your initial impressions on 4/3/15. I found your comments particularly helpful.

My initial concerns were lack of ability to exit on the opposite side (in the 1 person version)…but I could live with that, the gear storage area being exposed to rain in high winds…but I was willing to test it out, and now you have made another important point of which I was unaware. There is no way to close off the "garage door". That actually might be a deal breaker for me. Rain in high, gusty winds would likely spray right onto my head. Gear is one thing, but nobody wants water inside their tent.

So, has anyone actually trail tested this yet?

"Matt V,
Thank you for posting your initial impressions on 4/3/15. I found your comments particularly helpful.

My initial concerns were lack of ability to exit on the opposite side (in the 1 person version)…but I could live with that, the gear storage area being exposed to rain in high winds…but I was willing to test it out, and now you have made another important point of which I was unaware. There is no way to close off the "garage door". That actually might be a deal breaker for me. Rain in high, gusty winds would likely spray right onto my head. Gear is one thing, but nobody wants water inside their tent.

So, has anyone actually trail tested this yet?

Edited by LisaB on 04/13/2015 11:34:11 MDT."

Wow, I could have sworn there was a 'drop door' on the back wall (head side) like the side walls. Man, that is a total deal breaker for me. As someone who has seen winds shift 180 degrees within just a few hours, I will not buy this tent. Water and snow spray would be even worse. As mentioned in my previous comments I admire the ingenuity of SD, but this one is a no-go :(

I don't see anything that covers the window into the gear garage. The base of the awning is really wide, like 9 feet. It tapers to about 6 feet wide at the top. The fly provides about 1 foot of overhang past the base of the tent on the sides at the head side, at least, but not as much at the top because of the inverted trapezoid shape. I think the overhang tapers away as you go towards the foot side. The window into the gear garage is at least a foot away from the overhanging awning at the top, and the awning gets wider but farther away as you go down. As is, it certainly wouldn't be good for blowing snow, but I expect it would keep most rain out. I still haven't had a chance to test it out outside yet.

I plan to add a sil nylon panel that can roll down and cover the window into the gear garage. I haven't decided the best way to attach it yet, but I'll probably glue on some velcro since that's easier than adding a zipper. But I don't know how airtight I need it, and I don't want to add a whole lot of velcro. I'm thinking a few squares of velcro might do it, especially if I cut the panel a bit larger than the opening so there is some overlap. Water running down the panel could be an issue if rain spray hits it and it's on the inside of the tent, so I'll have to think about if there's a better way to do overlap it. I mostly want to have the option to reduce the amount of wind going through the tent, but keeping water out would be nice, too.

The doors are sewn along the bottom, so that should keep most water out if the inner panels are zipped up, and if you seal that seam you can keep all the water out. Maybe installing a nylon panel so that it rolls up from the bottom would be best. Can I simply glue it in place rather than sew it on? I'm not good enough at sewing to try it on a brand new tent!

To cover the mesh near the garage door, I don't think you'd want a waterproof fabric. That would reduce airflow substantially and probably make a condensation nightmare.

What might work well is just cutting to size and hemming a very light nylon with a DWR (like Argon 67 or something) that would cover the mesh near the garage door. This would block the wind and most any spray, and allow for some breathability, in addition to being lighter than silnylon.

Looking at pictures of the tent, I think you could use some mitten hooks to clip it on to the guyline tabs near the trekking pole handles at the top, and then clip it on to the tabs near the bottom corner of the tent. This would make it a non-permanent addition, completely removable, and easy to deploy with just 4 mitten hooks.

Hi, I am new to the site, and new to backpacking in general, so please be gentle. Due to an issue with an old SD tent, they were kind enough to offer me a great deal on a new tent. The tensegrity definitely interested me, for the same reasons as many others have listed. I had already ordered mine when I came across this incredible site, and really the only new/useful info on the tensegrity online.

I also had issue with being able to somewhat seal off the garage. Mine arrived and I just set off to set it up in the dark, and try my solution. Here is what I came up with, and it seems to work without altering the integrity of the tent. As I said, I am very new to backpacking so I greatly look forward to your opinions and criticism.

Here is what I did. I used the guylines provided to set up the tent as in stargazing configuration. This leaves the Garage totally loose. I used the center stake loop on the garage (yes there is one, but it is not generally used in the final set-up). Then I came up about a foot from the corner stake point on the garage and used a tarp clip (i will find a better solution, but for now it served to show proof of concept). Staking down the tarp clips basically made the garage into a tight triangle with the corners right next to the side doors. This still provided plenty of space for gear, left some airflow, but blocked off the window visually and should keep away and blowing precipitation.

I hope this makes sense. I apologize for the lack of pics, but I set this up at 11pm so it was a bit dark out there, but I really wanted to check it out. If anyone is interested, I will set it back up this weekend and take some pics. What upsets me is that SD could have made this an easy option by simply adding a second set of loops a foot up from the corner.

JJ,

Welcome to the site and thanks for the new perspective on the garage flap.

By all means, get some pics of the modified pitch . Current and future Tensegrity owners may find it very usefull!

JJ-

Thanks for teh post… whaty you've done sound slike a great mod, basically turning the garage into an enlcosed vestibule, if I understand right. I'll be anxious to see your pictures, and to see how it affects ventilation and condensation. If I'm envisioning it right, in full-on storm mode with the garage door battened down and the panels zipped shout on the side doors there wont' be much circulation and condensation could be a real opportunity.

as for your other concern:
"What upsets me is that SD could have made this an easy option by simply adding a second set of loops a foot up from the corner…"
that too is a great suggesiton, and if they're smart (they are!) they'll at least give it come consideration!

Thanks again. Have fun.