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Reviews > Shelters > Tents > Big Sky International Evolution 1P > Owner Review by Ralph Ditton


DATE: 17th March, 2009

                                                                               Summit Evolution 1P 1D 1V Shelter
                                                                                       Big Sky Evolution 1P 1D rev. G  Shelter

Personal Information

Name: Ralph Ditton
Age: 56
Gender: Male
Height: 1. 76 m (5 ft 9 in)
Weight: 71 kg (156.5 lb)
Email: rdassetts at optusnet dot com dot au
City: Perth. Western Australia. Australia

Backpacking Background
My playgrounds are the Bibbulmun Track and the Coastal Plain Trail. I aim to become a sectional end-to-end walker of the Bibbulmun Track. I am nearly there as it is 964 km (603 mi) long. My pack weight including food and water tends to hover around 18 kg (40 lb) but I am trying to get lighter. My trips range from overnighters to five days duration.

Product Information
Manufacturer: Big Sky International - Jackson, Wyoming - USA
Manufacturers website:
Year of Manufacture: 2007
Made in: Product of USA sewn in China.
Model: Evolution 1P 1D rev. G Shelter
Colour: Granite Grey
Sleeping capacity: 1
Number of poles: 2
Pole choice: Aluminium or Carbon
Aluminium poles: 7075 - T9 Easton main tube 8.74 mm (0.344 in)
                               7075 - T9 Easton insert tube 7.07 mm (0.303 in)
Tensile strength of aluminium pole: 67 Kg/mm² (96,000 PSI)  

Rainfly fabric: 30 D Silnylon
Inner fabric: No-see-um mesh
Floor fabric: 30 D Silnylon
ShelterSavers ground sheet with webbing tie straps
Factory seamed sealed: yes
Door: 1
Zips: 2 YKK on the inner and 1 YKK on the fly. All are 5 gauge.
MSRP: Shelter with aluminium poles only: US$249.95
              Shelter with a set of carbon and aluminium poles: US$349.95
              Carbon Poles only: US$100
               ShelterSavers ground sheet without grommets: US$14.95

Shelter without accessories + carbon poles 916 g (32.3 oz) 934 g (32.8 oz)
Shelter without accessories + aluminium poles 1005 g  (36.9 oz) 1056 g (37.3 oz)
Pole diameter: Carbon 7.42 mm (0.292 in) 7 mm (0.275 in)
Pole diameter: Aluminium 8.74 mm (0.344 in) 8 mm (0.314 in)
Weight of Carbon poles Not Listed 216 g (7.61 oz)
Weight of Aluminium poles Not Listed 338 g (11.92 oz)
Diameter of repair pole sleeve Not Listed 9 mm (0.354 in) inside
11 mm (0.433 in) outside
Weight of repair pole sleeve Not Listed 8 g (0.28 oz)
Floor length & tapered width dimensions 213 cm x 91 cm x 61 cm
(84 in x 36 in x 24 in)
213 cm x 91 cm x 61 cm
(84 in x 36 in x 24 in)
Peak Height 99 cm (39 in) 1 m (39 in)
Floor Area 1.62 sq m (17.5 sq ft) 1.62 sq m (17.5 sq ft)
Vestibule Area 0.84 sq m (9 sq ft) 0.79 sq m (8.5 sq ft)
ShelterSaver length & tapered width
200 cm x 79 cm x 53 cm
(79 in x 31 in x 21 in)
204 cm x 79.5 cm x 53 cm
(80 in x 31 in x 21 in)
Packed size 13 cm x 48 cm
(5 in x 19 in)
14 cm x 48.5 cm
(5.5 in x 19 in)
Weight of rainfly Not Listed 342 g (12.06 oz)
Weight of inner Not Listed 376 g (13.26 oz)
Weight of stuff sack Not Listed 35 g (1.23 oz)
Weight of ShelterSaver groundsheet with ribbon tie straps Not Listed 74 g (2.6 oz)
Internal loops inside inner Not Listed 7
Accessories - guy lines & stakes
2 Easton aluminium stakes and 6
Ti stakes kit
77 g (2.7 oz) 70 g (2.5 oz)
4 reflective spectra guylines with
4 Easton aluminium stakes kit
61 g (2.1 oz) 70 g (2.5 oz)

I became aware of a new improved version of the Big Sky Evolution 1P 1D shelter when I placed an order for a new set of poles as I had broken one of the original poles that came with my original Evolution 1P 1D. In addition I also ordered a guy line kit and tent pegs as they were not supplied initially.

The manufacturer spoke of the virtues of the new version during an exchange of emails regarding the above order. I agreed that it looked different and that I would like one. That was the 27th December 2007. The Evolution 1P 1D  rev. G arrived on the 24th January, 2008. A few days short of a month for the order to come from America after placing it is quite an acceptable time frame in my opinion. Normally the transit time is between ten and fourteen days.

I had no difficulty  with the manufacturer and they responded quickly to any query that I had regarding the order.

I listed the tensile strength of the aluminium poles for the technically minded as I had the sad experience of breaking a pole when erecting the original shelter.

Product Description

The Big Sky Evolution 1P 1D rev. G shelter is a one person, free-standing, one door, one vestibule shelter with an inner and a rainfly. In fact, there is a de facto vestibule also on the non-door side.

The cut of the rainfly (or 'fly')  at the rear has an allowance at the bottom which means the fly has to be stretched out and pegged. This created the de facto vestibule which is the same in area as the official vestibule on the door side.

To gain access and put items in there, I have to lift the stake loop over the tent peg and lift the fly up. When finished, I just slip the stake loop back over the tent peg. There is no zippered access to it.
Note. Big Sky does offer a 2 Door version with door and vestibule zippers on both sides. The 2 Door version has two vents and four pockets. The 2 Door version is US$15 more and adds 104 g (3.6 oz) to the weight. The manufacturer advised me that the reason for the design decision is that in most cases those purchasing the 1 Door version want light weight  so it has fewer features that add weight, for example: it has two pockets, while those purchasing the 2 Door version want more features, so it has 4 pockets.

A) The fly.
The colour of the fly is Granite Grey and the material is silnylon, but to me it looks like a very light olive green and I find that it is a very pleasing colour.

                                                        colour coded strips and clip
                                                                                           colour coded strips and clip

There are four plastic/nylon type material dog clips that clip onto the respective loops on the inner. There is one on each corner. Two at one end of the fly are attached to red strips of material that are sewn to the edge of the fly. The other two clips at the other end are attached to black strips. This is the colour coding to match the fly to the inner as there are red and black strips on the corners there also.

There are four cord tie down points around the perimeter of the fly. They are all halfway on each side.
The door entry runs vertically from the base to the vent at the top. Underneath the flap covering the zipper there are two small patches of hook and loop, one at the bottom and the other about halfway. So when I go to open the fly I have to break apart these two patches so that the fly can be opened for me to get in and out of. The zipper pulls are yellow cord with a reflective strip woven into them. On the zipper slider there is one for the outside and one for the inside of the fly.
                                                           vent prop
                                                                                                        vent prop

At the top of the fly there is a vent that can be propped open by a little rod covered in silnylon that has a little floppy foot of loop (as in hook and loop) that bends and it marries up with a patch of hook on the other edge of the vent. The vent can only be opened so far because there is a strip of black ribbon that is attached to both sides and spans the vent.

The fly is thrown over the inner and is secured to the poles by way of a wrap around hook and loop system. They are underneath and around halfway along the stitched seams.

Along the outside ridge lines created by the poles that are clipped to the inner, there are reflective guy line loops about halfway along. On the door side immediately above each of these reflective guy line loops there is a toggle which marries up with a loop on the underside to keep the door open when rolled back.

The final piece de resistance is the "Egyptian Eye" window sewn and seam sealed into the fly. It is 24 cm long and at the highest point 10 cm (9.5 in x 4 in). At certain spots along the seam I can see where the seam sealing brushwork was a bit dodgy as it has intruded onto the window from between a half and full brush width of 8 mm (0.3 in). The bottom edge is the one mostly affected.

B) The inner.
                                                                      the inner
                                                                                                          the inner

The tub floor is made out of silnylon and is navy blue in colour. The height of three of the sides is 17 cm (6.7 in) and the head end is 24 cm (9.4 in).

                                                        corner of inner                                                                                                                                                   corner of inner               

From each of the four corners of the tub floor come two strips of material that are joined to a piece of webbing that has a grommet and elastic loop. The grommet hole is for the end of the tent pole to hook into and the webbing is an anchor point for a tent peg. If I do not peg out the corners, the tent poles have the habit of creeping back together by some 8 cm (3 in) i.e. 4 cm (1.5 in) each. I want to stretch out the tent for maximum space  When stretched out fully the straps form a triangle with the side of the tub floor forming the vertical base. At the foot end, two of the straps are red for the colour coding match up with the fly.

Stitched to the tub is a canopy made of no-see-um mesh. Attached to the outside of the canopy along the seams that run diagonally from corner to corner are the pole clips that hook onto the tent poles. There are fourteen of them. At the very apex, instead of a pole clip there is a loop and buckle. This is where the poles cross over. Just like on the fly and in the same position, there are four reflector guy line loops that serve a purpose when the inner is being used only.

The door is quite generous in size. It is 80 cm (31.5 in) high and 109 cm (43 in) long at the deepest part.
The end that opens is gently curved. The two door zippers have two reflective zipper pull loops attached to them. One for the inside and the other for the outside operations.

Inside the tent there are two pockets whose dimensions are mentioned above under "Lengths". They are both on the door side of the canopy.

There are seven accessory hanging loops along the seams. Four of them are clustered in such a way that they are anchor points for a gear loft. There is one loop that is at the very apex of the canopy and the other two are located 40 cm (15.7 in) above the tub line at the head end for hanging a light or attaching a clothes line.

To hold the rolled open door together, there is a toggle and loop arrangement to facilitate this.

C) Fabric
I contacted the manufacturer to find out the denier of the silnylon, the weight of the fabric per square metre and tear strength. I was advised that the nylon is 30 denier with silicone coating on both sides. The manufacturer does not give out the exact weight of the fabric per square metre expressed as g/m² (grams per square metre) nor tear strength. However, the manufacturer advises and I quote, "the material is light weight and strong or stronger than similar fabric used in other shelters on the market."

In addition I asked if the floor has a very high puncture and abrasion resistance. The response was that they use the strongest nylon yarn in their fabric for strength and abrasion resistance.
 Bearing this information in mind I did not worry too much when I pitched my tent over some tiny vegetation. Sadly I did manage to accidentally punch a tiny hole through the floor from a very tiny drought resistant bush. See my Granite Monolith walk below.

Changes/New Features
I have an earlier rev. B version of this tent and there are a number of alterations and new features in the "Improved" rev. G version.
The differences are set out below:

Weight 392 g (13¾ oz). 342 g (12¼ oz).
Vent No strap spanning across the base. Strap spanning across the base.
Window Larger. 26.5 cm x 12 cm
(10.4 in x 4.7 in)
Smaller. 24 cm x 10 cm
(9.5 in x 4 in)
Weather flap over doorway
Opens to the left. Opens to the right.
Stake out points No loops at halfway point at base on front and rear. Loops at halfway point at base on all four sides.
Vestibules One Two
Tent pole set up Grommets at each corner for the pole tips to lock into. Clips at each corner that clip onto the inner.
Weight 464 g (1 lb 3/8 oz) 376 g (13 ¼ oz)
Tent pole set up Two pole sleeves. Fourteen pole clips.
Pockets Two - One the same size as in the new version. The other is a very large triangular pocket. On alternate sides. Two- One the same size as in the old version. The other pocket is very much smaller. Both on the same side.
Total weight of fly and inner 856 g (1 lb 14.2 oz). 718 g (1 lb 9.3 oz). Note: rev. G is 138 g (4.9 oz) less weight than rev. B
Field Information
My first trip with this tent was for two days and one night and took place on the Bibbulmun Track around the Murray River campsite. Temperatures during the hike ranged from 28 C to 33 C (82 F to 91 F). Humidity I estimated was around 70% judging by the amount of sweat on my clothes. Elevations ranged from 143 m to 280 m (467 ft to 919 ft). The Ultra Violet Index peaked at 9 which is very high.

 During the evening when I went to bed around 8.30 pm I estimated the temperature to be about 18 C (64 F). I had the tent door on the fly zippered closed and the vent open. I did not leave the tent during the night, but when I got up at 6 am I noticed that there was a light mist present.
Because of the mist, I checked under the fly and sure enough, there was a very thin film of condensation that left a track in it when I drew my finger through it.
When I was packing up the tent I gave the fly a good few flicks but did not notice any moisture flying away from the fabric.

I was impressed with the two vestibules. I utilized both of them and the lifting up of the tent peg loop over the tent peg to gain access to the gear did not irritate my emotional well being. I had to go back and forth getting stuff as the afternoon progressed. Yes, I could have left the vestibule collapsed until I went to bed, but I liked the look of it fully pegged out. As an aside, in bad weather it would have to be fully pegged out to stabilise the tent.

There were a lot of flies and very small biting insects but they did not gain access to the interior of the inner canopy although they buzzed and crawled around on the outside of the no-see-um mesh. I had a very sound sleep.

My next trip was over the Easter break at Greens Island in the south west of Western Australia.
This was a four day, three night camp out. I found a nice spot to pitch the tent just under a low hanging pine tree branch.

For the first two nights it rained but not heavily. Just a steady patter on the tent fabric which was very soothing to listen to.

Temperatures overnight averaged around 10 - 12 C (50 - 54 F). I had the vent open on all nights and no rain entered through it. Due to the high humidity and relatively still nights I was very surprised to find that there was no condensation inside on the fly, nor did the no-see-um mesh feel damp.

The window was not much help as it was fogged over from the rain. On the morning when it did not rain overnight the window looked opaque and I couldn't see too much through it.

 During the day little ants tried to get inside the tent. All that they succeeded in doing was to crawl all over the fly. I sprayed the fly fabric with my personal insect repellent which has the active ingredient of picaridin. It is tropical strength at 14.25%. I sprayed the tent on all three days. No damage was suffered by the fabric.

When I got home, I washed the fly in warm water only to clean off the spray and dirt that had adhered to it after being wet. The rain beaded well on the fabric.
The next trip was to the Granite Monolith area south of Perth. This was an overnighter. The overnight temperature from 7 pm to 6 pm when it was dark ranged from a high of 18 C (64 F) to a low of 12 C (53 F). Relative Humidity was stuck around 88% and it was very still with a clear sky.

What this meant was that there was condensation on the tent even before I went to bed. Everyone's tent was wet before they got into theirs as we all commented about it.

Needless to say, condensation also formed on the inside and where the inner touched against the fly it got wet. Some moisture did fall onto my sleeping bag but did not affect the down due to the waterproofing material of the sleeping bag.

I did not have the choice of a large area to pitch the tent as the ground was sloping and had a lot of spiky short drought-resistant bushes. When I put my hand down on the ground it got pricked by very tiny little spikes like the very fine hairs from a blister bush. I swept the ground as best as I could.

I did not carry a ground sheet so the floor of the tent went directly onto the ground. My sleeping bag and mat fitted very well inside the tent without either end touching the ends of the inner. This prevented the inner being pushed up against the fly and getting wet there. I placed my backpack in the de facto rear vestibule and the pack touched against the fly and it got wet where it touched. Moisture did not penetrate inside the pack. In the morning when I was packing up I noticed that a little bush had managed to puncture the floor, leaving a tiny pinprick of a hole. As the fly was very wet I flicked as much water off it as I could when packing up. In the process I got a good drenching also.
                                Summit Evolution 1P 1D 1V Shelter
                                                                           Big Sky Evolution 1P shelter

Upon returning home I washed the tent in plain luke warm water to clean it up as dirt had stuck to the floor.

After this trip I purchased the new ground sheet designed for this model tent. It is called "ShelterSavers ground sheet" The model that I purchased does not have any grommets to hook onto the pole tips. Mine has coloured tapes which indicate which end they tie to. They match up with the colour coding straps on the inner. The ground sheet is tapered to match the base of the tent; wide at the head and narrow at the foot end.

                                                                                   ShelterSaver ground sheet
                                                                                                 ShelterSaver ground sheet       

The photo below shows the tie for the ground sheet. The red tie matches the red strap so I have the ground sheet at the right end.
                                          ties on ground sheet
                                                                                      ties on ground sheet                                                                                                                     
On my next outing I went to the Coastal Plain Trail where elevations range from 20 m to 80 m (65 ft to 197 ft) and the soil is very sandy. The trip lasted three nights and it rained on the last night while I was inside the tent.
Overnight temperatures over the three nights ranged from a low of 0.3 C to a high of 10.8 C (32.5 F to 51.5 F). (Source: Bureau of Meteorology).

When I erected the tent, I noticed that the window had a patchy milky look. I tried rubbing it with a cloth and tissues, all to no avail. It would appear that the plastic of the window has been "bruised" in places thereby causing the milky appearance. I have notified the manufacturer. The polyurethane material (PU) is very soft and pliable in my fingers, whereas on the old version the polyvinylchloride (PVC) material is stiffer and is still very clear.

                                            window with milky look
                                                                                   window with milky look

The orange colour seen through the window is my sleeping bag.

I heard back from the manufacturer very quickly who asked that I send the fly back to them so that they could examine the window and replace it with a clear window.
After a few weeks the fly was returned with a new window. There is no cloudiness at all in the new window. I was extremely pleased with the turn around time and quick response to my problem. The only expense that I suffered was the postage cost to America which came in around AU$10.

As this tent is a single person tent, there is not a lot of room left inside after putting my sleeping mat and sleeping bag inside. I always place a relatively full clothing stuff sack behind my pillow so that it fills the gap between the end of my mat and the wall of the tent so that the pillow does not end up on the floor of the tent during the night. The sleeping mat is quite thick, some 7 cm (2.8 in) so if the pillow slips off the end of the mat it drops down a fair bit. The tent has not suffered any adverse affect  to either the stitching between the mesh and tub floor due to a slight pushing out of the tub floor by the stuff sack or to the tub floor, i.e. there are no stretch marks.

                                            looking inside the tent
                                                                                looking inside the tent

During the course over the three nights I only experienced a very thin film of condensation on the underside of the fly for two of those nights. They were the first night and the last night. The Dew Point got close to the temperature on a few occasions. The first night the Dew Point was 0.2 C (32 F) and the temperature was 1.5 C (35 F) at 1 am. The closest the Dew Point got on the second night was 2.7 C (37 F) when the temperature was 5.1 C (41 F) at 10 pm. The final night was when it rained. The Dew Point was 9 C (48 F) and the temperature was 10.7 C (51 F) at 6 am whilst the humidity was 94%.

The fly was very wet on the outside surface so I had to flick off as much water as I could before packing the tent away. I packed the inner away separately as I did not want to get it wet also.
                                              rain on fly
                                                                                                   rain on fly

Subsequent outings have been to my favourite retreat at Prickly Bark on the Coastal Plain Trail where I love to go and chill out. There is a three sided shelter at the campsite but I prefer the tent as it offers protection from the flies, wasp and ticks that inhabit the area.

Yes, I have had condensation issues on cool, dew laden still nights, but I have experienced this problem with other tents also, so it is not a fault of the tent. Condensation occurs when the temperature of a surface (or the air) falls far enough that the relative humidity reaches 100%. As the temperature falls further the excess water has to come out of the air and condense somewhere.
I have had this tent for over a year now and have used it extensively during the year at various locations in Western Australia.

The performance has been excellent and I love the size of the vestibule space on the door side and the de facto vestibule on the other side which is created when the fly is pegged out. It is a good place to store my backpack and boots so that they are out of the way as I don't use them whilst in camp. I always have camp boots/shoes for around camp and they live in the vestibule on the door side together with my cooking gear, stove, fuel, pot and eating utensils.

I alternate between the carbon and aluminium poles just to give them both equal usage.
Recently, I used the older rev. B version to see if I missed it and yes I did as I love them both. What I would love to see is the larger pocket on the older version incorporated in the newer version. I doubt that there would be any weight gain. The larger pocket is great for placing a damp shirt in the pocket to assist with drying during the night.

What type of pole assembly do I prefer? Pole sleeves or clips? On balance, probably the clips. It is definitely much easier to erect and pull down using the clips. With the pole sleeve, the pole tip is scraping along the top of the pole sleeve when it reaches the top of the tent and then starts to bend over to go down the other side. I have to be careful that I do not punch or wear a hole through the sleeve and I have to assist it in the latter stages of feeding it through the sleeve as it can bunch up.

The follow up service by the manufacturer was excellent and this speaks volumes about them caring for their product.



Read more reviews of Big Sky International gear
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Reviews > Shelters > Tents > Big Sky International Evolution 1P > Owner Review by Ralph Ditton

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