Why few freestanding Cuben Tents?
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Hi Roger,
Here is the latest scale model:
The model is mostly for visualization, as you requested. The rear peak has been dropped 8″ from the 4 foot high front peak, and the rear peak elbow angle increased to 150 degrees compared to 120 for the front peak elbow . This allows for a much smaller and lighter rear vestibule for storage space – the foam block in the photo represents a pack. One other thing with the scale model (1″ = 1′) is the dimensions can be determined, and the weight of the fabric calculated as part of a weight estimate for the tent.
Left the rear vestibule with two pegs as you suggested. The flexible poles in the model are music wire, and will be made from Gold Tip carbon Expedition Hunter 75/95 shafts for the actual tent. But I don’t make them until the exact length is determined using some ancient SMC light alloy poles. The wooden sticks do not represent poles – just seam lines, which are inaccurate, as a catenary cut will be put in the vestibule seams during construction.
The weight penalty for a ridge pole will be 1.16 oz, not counting ferrrules, end tips, and shock cord. Due to the slope of the ridge, I don’t think this design will pool water on top, but a ridge pole will help greatly with shedding snow, and will strengthen the structure. The ridge pole will project over the peaks to hold up vent awnings, but on the model is just represented by a short wooden stick between the peaks – vent construction to come later. It will be made from Easton carbon Axis 500 shafts that are lighter and more flexible than the Gold Tip shafts.
This design does not require a wooden construction frame because the main canopy assumes its bowed out shape when stretched over the frame, as the fabric will stretch more on the bias than with the grain. The vestibules are another matter, but once the main frame is built, and the fabric attached over it, a wooden frame has not been necessary to make the vestibules on other tent projects.
The fabric is still in question, but the 1.06 oz Extreme Textil 20D silnylon looks good. It should be a lot stronger than lower denier fabrics and almost as light. Figure a weight penalty of 0.36 oz/sq/yd over the 0.7 oz Rockywoods 7D, the lightest of the 7D fabrics AFAIK. But won’t decide until I finish testing and post on the ExTex, and see what others may say.
So this is pretty off-piste, inasmuch as an unwoven material like DCF, would not bow out on the bias (not without a heat gun, hah-hah).
Bought a roll-out generator and transfer switch years ago due to the constant power outages in our neighborhood. A quick story. When we built a new county courthouse, I tried to get a generator put in, but was denied. At the building dedication, all the muckety-mucks showed up, but during the ceremony, the power went out, and stayed out. My boss was secretly amused because he had joined me in trying to get the generator. ‘I-told-you-so’s’ are deemed unseemly, but we had a good laugh later.
Once the ridge pole is flexed to create a convex ridge, it will shed precipitation better; but there is the danger of the pole rotating in high winds and/or heavy snow to create a concave ridge. Supporting the vent awnings is nice, but they also anchor the flexed ridge pole so it won’t rotate under pressure.
One of the tents that addressed this issue was made by Steve Noall and was called the ‘Solitary Base.’ It also used the vent awnings to stabilize the ridge pole, but instead of being flexed into an arc, it had two pre-bends that served as elbows. It looked like this:
The bends were sharp enough to keep the ridge pole solidly in place. But I think one could do as well with a pole flexed in an arc. And that’s the reason for the extensions; not just to support the vent awnings, but also to stabilize the ridge pole in its sleeve, not to mention supporting the fly overlapping the peaks and the inner tent underneath. Whether Steve Noall’s sharper angles on the ridge pole are needed remains to be seen.It was already noted on this thread that trekkertent (spelled as one word) makes traditional domes with the poles crossing only once at the top center, and that they can be ordered in DCF, and also in silnylon, about 10 ounces heavier. And they have a nice version of the old Phoenix Phreeranger, similar to the TarpTent Rainbow, that also comes in DCF.
But after doing the math, I also think that my pop-up can come in close to 2 lbs in silnylon, without using DCF, and using 20D Extrem Textil silnylon for the vestibules, adding less than 1.6 oz to what the vestibule weights would be using 3/4 oz DCF. Great for those who wish to pack small, as well as light. Granted, many can now pack with solo tents close to a pound using DCF and trekking poles for tent poles. But they may not be as stable in heavy winds and precipitation as better designed pop-ups and tunnels. That may have been part of what the OP was thinking about.
Thank you for bringing us to greater appreciation of tents that function well in severe weather, in winter as well as other seasons.
“One of the tents that addressed this issue was made by Steve Noall and was called the ‘Solitary Base.’”
I vividly remember Steve Noall’s tents back in the early 90’s. They seemed to carry a reputation of being very well made tents back in the day. I especially remember the Mountaineer II (even though I felt it was a little short for me:)
Of course when it came out, it seemed like a tweaked variant of the Moss Stardome:
Which was simply a four season version of the early 80’s Stargazer:
(Sigh….)
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