Ron at MLD has announced he will be making an inner bug nest for the DuoMid. A followup email with Ron estimates it will come in at 12-14oz. This puts the silnylon DuoMid at 27-29oz with inner. My TT Rainbow weighs 30.8oz (tent & poles). With a trekking pole extender on the DuoMid, that would put the two shelters at nearly identical weights.
So, which one do you think is more wind stable?
This is a rather loaded question, so let me unpack it a little. First, let's make a few assumptions: 1) the DuoMid is being held up by a CF trekking pole with extender, and 2) the Rainbow has a pair of CF trekking poles in the cross strut grommets, with the mid-height arch sleeve pullouts secured in a V-shaped guyout configuration.
Let me point out that the answer is not as easy as it may seem. For example, the pyramid shape of the DuoMid is the classic wind-resistant shape. But it relies solely on a single trekking pole. Reviewers have reported in the BPL forums of their aluminum poles being bent in high winds in their GoLite Hex 3 / Shangri-La 3. Presumably there is a wind speed strong enough to catastrophically snap a CF trekking pole in a pyramid design. The DuoMid also has no side pullouts (arguably not needed, but the fact remains), and the DuoMid is taller.
The Rainbow's obvious weakness is the 12' arch pole, prone to snapping. But having set up a Rainbow with dual trekking poles at the cross strut and securing the mid-height arch sleeve, I can testify that it would take a seriously strong wind to bend the 12' pole hard enough to get it to snap. Would the DuoMid pole still be standing in winds this strong? Plus, the Rainbow is able to distribute the pressure between two trekking poles and the arch pole, whereas all of the lateral wind force must be absorbed by the single pole of the DuoMid.
See how the answer becomes less obvious?
Lastly, I would like to state that I believe both shelters are excellent choices, and I don't think this thread should degenerate into which tent is better. Both have many strengths and very few weaknesses, and one should let the features they prefer guide their decision. Therefore I would like to limit this thread to comparing the wind resistance, which is just one of many comparisons. I have chosen these two tents because they appear to share the following features above other tents: best-in-class wind resistance, excellent solo interior head room, can comfortably accommodate a 2nd person, fully enclosed from bugs and weather, and sub 2 lbs.
EDIT: I should note that the DuoMid has an apex loop, so one could add guyline, even dual V-shaped guyline, from the top of the DuoMid to stakes a few feet away in the direction of the wind. Would this significanly reduce stress on the center pole to give the DuoMid the wind advantage?
EDIT 2: The DuoMid now has side pullouts on all four sides. Also, the DuoMid InnerNet is 82" long; not long enough for a 6'2" person on an inflatable pad unless he or she sleeps on the diagonal. It means this is just a solo shelter for taller hikers. Then again, the Rainbow is narrower than the DuoMid, so it is a tight squeeze for two as well. Both would fit two in an emergency, but neither would be very comfortable. Lastly, the Rainbow should offer more percieved inerior space with it's steep walls and lack of center pole. But now I'm drifting into non wind-related comparisons…
