Macpac Olympus - can't fit two sleeping pads in!? Help!

[Ent]

... that the air is for comfort ...

Not really.
Unless you are rewriting the laws of thermodynamics, emissivity plus reflection = 1, and . Aluminium is about as good as it gets. Unless you are the space program or bugatti.
Air is a good conductive barrier.
That is why in theory one of the best insulators is two layers of aluminium foil separated by a millimeter of air. Radiant> conductive> radiant barrier. Unfortunaltely it is not all that easy to achieve.
In practice the introduction of rigid foams etc is for mechanical stability and fabrication.
Neoirs are essentially providing air separated reflective foils.

Both correct and incorrect. Air as in a lielow with no baffles is pretty much useless as an insulator but if trapped and not moving as say with down in downmat then it is. Yes the use of foil correctly with air as in the lastest NeoAir is impressive until it goes flat. I have both the older and newer model and the older blows up the same height if not thicker but the the newer one is so much warmer. So yes and no. Trapped air is a good insulator but air allowed to roam is no much chop as air cooled engines would not work. Ironically a great insulator is a vacuum but outside a vacuum flask rather hard to achieve in a sleeping mat. But rather off topic. Surely a Macpac store can chuck in a couple of large mats and see what happens?

Regards

[Rob A]

What I was pointing out is e+r=1, two walls, conductive barrier. No argument about that. How much success Neoair has in practice with their manufacture should display in their measured R value. Personally, I find em pretty good.
The trapped air is not a radiant barrier (nor is a vacuum). The aluminium(foil) is not a conductive barrier.

images.jpeg (7 KiB) Viewed 9014 times

Ohhh ... A large 'mat'! Never mind, we will be amuned.

[ryantmalone]

crap in the cold

2.5-inch thickness can't be too crap in the cold... I don't have one so cannot comment.
The review rates it as the second warmest out of 17 mats. And it's tapered which may assist the OP.

I own a NeoAir All Season, not too much difference between that and the xTherm apart from a slightly lower Rvalue (4.9 vs 5.7) and the thing is ridiculously comfortable, and ridiculously warm.

You can literally feel the heat coming off these things, they are that good.

In simple terms, they are baffled in such a way that they don't deflate as much in certain areas when you sit on them, or when your weight is distributed unevenly on them, plus they have a layer in the middle that reflects the cold down (slowing snow melt on the ground), and that reflects your body heat upwards, back to your body.

[Onestepmore]

So at the 180 cm mark you're going to have 7.5 cm overlapping on each mat?

Depends on which measurements you go by, my translation is 4 centimetres overlapping on each mat at the 183 centimetre mark.

PS Hubby just came in with his 2c worth. He reckons it's more important that the mats stick together, than if they fit.

A valid point not related to this topic, but as I walk usually with my wife, it would be great if the two expeds clipped together so as not to allow the creation of a gap between us through the night (that I invariably end up in).

This is bugging me. And I'm a Scorpio, so that matters.
Ok - width of tent is 85 cm (at 180 cm down measured from the top/head)
Width of each mat is 50 cm - so x 2 = 100 cm
100 cm - 85 = 15cm overlap

My maths is wrong
So I am wrong in saying it's 7.5 cm overlap, and I can't work out where your 4 cm overlap comes from
Hubby and I have just been playing with pieces of paper, and he was right (of course)

This would be sligthly more at 183 cm down, and exaccerbated if the sleeping mat wasn't up hard to the top of the tent wall

[Strider]

So at the 180 cm mark you're going to have 7.5 cm overlapping on each mat?

Depends on which measurements you go by, my translation is 4 centimetres overlapping on each mat at the 183 centimetre mark.

PS Hubby just came in with his 2c worth. He reckons it's more important that the mats stick together, than if they fit.

A valid point not related to this topic, but as I walk usually with my wife, it would be great if the two expeds clipped together so as not to allow the creation of a gap between us through the night (that I invariably end up in).

This is bugging me. And I'm a Scorpio, so that matters.
Ok - width of tent is 85 cm (at 180 cm down measured from the top/head)
Width of each mat is 50 cm - so x 2 = 100 cm
100 cm - 85 = 15cm overlap

My maths is wrong
So I am wrong in saying it's 7.5 cm overlap, and I can't work out where your 4 cm overlap comes from
Hubby and I have just been playing with pieces of paper, and he was right (of course)

This would be sligthly more at 183 cm down, and exaccerbated if the sleeping mat wasn't up hard to the top of the tent wall

From here:

The width of the tent at a point 183cm from the front door is about 92 cm wide.

100cm - 92cm = 8cm

8cm/2 = 4cm overlap

[Onestepmore]

How can it be 92 cm wide 183 cm from the front door, if it's 85 cm at 180 cm? It's tapering, ie getting narrower as you go futher down, not wider!

And overlap doesn't halve the amount...

I need another glass of this surprising glass of French Muscat from my friends' vineyard...
Women spatially unaware...... grumble grumble

[tasadam]

How can it be 92 cm wide 183 cm from the front door, if it's 85 cm at 180 cm? It's tapering, ie getting narrower as you go futher down, not wider!

And overlap doesn't halve the amount...

Ok, where I think you are getting confused is that we are looking at two different measurements.
The sketch on the piece of paper as posted in this reply is a measurement taken by the OP (Original Poster) as they say

Attached is the back-of-the-envelope dimensions my partner took with a tape measure and the tent set up (indoors in our lounge - so not guyed out with tension in the fly but would this affect the floor footprint?). Also because of the 'bathtub' floor it's hard to measure EXACTLY

so, as per the measurements taken in the Macpac shop, the numbers are approximate.

Lets look at something different.
Forget the maps overlapping, imagine they are going to be squished into each other instead.This makes the maths work - if one was overlapping the other by 4CM, you are only losing 4cm, thus 50 + 46 = 96, not 92.
So to get 92cm, you need to lose 4cm off both mats - they either need to squish into themselves by 4cm each, or into the tent walls a bit, or a bit of both.

Obviously with the lesser numbers obtained from the sketch, there would be a greater overlap, I won't bother with those maths because I suspect the measurements are not real world enough.

So lets have a look at a third option, lets take the tent plan from Macpac and enhance it a bit, overlay some (rough) evenly spaced bars and calculate their size based on a known size, then see what fits where...

So with these rough calculations based on the Macpac plan, it would appear that the 183 x 50cm mats would indeed fit!

[Strider]

crap in the cold

2.5-inch thickness can't be too crap in the cold... I don't have one so cannot comment.
The review rates it as the second warmest out of 17 mats. And it's tapered which may assist the OP.

Sounds like your talking about the XTherm...

[Strider]

How can it be 92 cm wide 183 cm from the front door, if it's 85 cm at 180 cm? It's tapering, ie getting narrower as you go futher down, not wider!

And overlap doesn't halve the amount...

Starting with 8cm extra width, move each mat 4cm inboard and what are you left with? A decrease in width of 8cm.

The taper thing does not add up though, you're right.

[Onestepmore]

[quote="Onestepmore"
And overlap doesn't halve the amount...

Starting with 8cm extra width, move each mat 4cm inboard and what are you left with? A decrease in width of 8cm.
The taper thing does not add up though, you're right.[/quote]

Yes, you're right and I am wrong about halving the total overlap for each mat. I was getting tired and going around in cirles. I was lying in bed this morning and realised what I had written there was incorrect.
I was also trying to work out how it could go from 100 cm to 92 cm over a distance of only 3 cm - it would be very steeply angled. So I was doing trig in my head to work out the angle slope, hypotenuse and horizontal axis length etc.
Then I decided not to, lol
Sorry for adding to the confusion

[blacksheep]

Short answer is the floor plan has been unchanged for the 15 years our records go back, and two full length non tapered mats will overlap at the foot.
Thanks to Adam for explaining it with piccies.
I'm in Takayama today in the hills in Japan. My bed is probably smaller than an Olympus;)

[Son of a Beach]

they have a layer in the middle that reflects the cold down (slowing snow melt on the ground), and that reflects your body heat upwards, back to your body.

Technically, cold cannot be reflected. Cold is merely the absence of heat. But the heat reflecting upwards, as you said (and the insulation) is what counts.

[Strider]

[quote="Onestepmore"
And overlap doesn't halve the amount...

Starting with 8cm extra width, move each mat 4cm inboard and what are you left with? A decrease in width of 8cm.
The taper thing does not add up though, you're right.

Yes, you're right and I am wrong about halving the total overlap for each mat.[/quote]
I was even confused there. Total overlap would = 8cm.

[Strider]

Technically, cold cannot be reflected.

But it can be insulated against. Insulation is more so a barrier to cold, than it is a reflector of heat.

[honey hale]

Thanks everyone for all your thoughts/input and for doing so much math!

We are now leaning towards getting a couple of Expeds, either Synmats or Downmats (if we can scrape together the $$ - annoyingly we JUST missed all the local post-xmas sales!) I'm personally not a fan of sleeping on 'blow up' type beds unless they can be made really firm (I sleep on a futon and hate 'regular' springy mattresses) but anything will be better than my old 15-year-old microthin Thermarest!

Whatever we end up getting, we'll take lots of photos of the setup to post on the forum - we're going on our first camping trip here in Oz in a couple weeks

Cheers,
Sharon

[Son of a Beach]

they have a layer in the middle that reflects the cold down (slowing snow melt on the ground), and that reflects your body heat upwards, back to your body.

Technically, cold cannot be reflected. Cold is merely the absence of heat. But the heat reflecting upwards, as you said (and the insulation) is what counts.

But it can be insulated against. Insulation is more so a barrier to cold, than it is a reflector of heat.

Obviously. I was merely replying to somebody who said that it reflected the cold (as I quoted).

Thanks everyone for all your thoughts/input and for doing so much math!

We are now leaning towards getting a couple of Expeds, either Synmats or Downmats (if we can scrape together the $$ - annoyingly we JUST missed all the local post-xmas sales!) I'm personally not a fan of sleeping on 'blow up' type beds unless they can be made really firm (I sleep on a futon and hate 'regular' springy mattresses) but anything will be better than my old 15-year-old microthin Thermarest!

Whatever we end up getting, we'll take lots of photos of the setup to post on the forum - we're going on our first camping trip here in Oz in a couple weeks

Cheers,
Sharon

I don't think you'll be disappointed. Whether you have long flat rectangular mats that overlap a little, or long tapered higher mats that do not overlap, the Olympus is a fairly roomy two person tent, compared to many other two person tents I've used. Of course I'm only about average height, so your mileage may vary.

[tasadam]

I'm glad we got this resolved.

Sorry for confusion created with my use of the word "overlap" - that was wrong and I have since edited my original comment.

[wildernesswanderer]

crap in the cold

Always though you gave quite good advice on stuff, but that is just so out of it it's not funny, want to back that up with some facts. The XTherm mat is excellent and very warm. I love mine

[ryantmalone]

they have a layer in the middle that reflects the cold down (slowing snow melt on the ground), and that reflects your body heat upwards, back to your body.

Technically, cold cannot be reflected. Cold is merely the absence of heat. But the heat reflecting upwards, as you said (and the insulation) is what counts.

Insulated/reflected, same meaning to me.

There's a reason why I never became a scientist.

[Son of a Beach]

they have a layer in the middle that reflects the cold down (slowing snow melt on the ground), and that reflects your body heat upwards, back to your body.

Technically, cold cannot be reflected. Cold is merely the absence of heat. But the heat reflecting upwards, as you said (and the insulation) is what counts.

Insulated/reflected, same meaning to me.

There's a reason why I never became a scientist.

Fair enough. I do get a bit pedantic at times.

[casey79]

Here are a couple of photos showing the Olympus with two mats side by side.

The first show a old regular thermarest next to a current prolite and neo air.

The second is a close up of the feet there is about 10-7cm overlap with the old mat and prolite and very little with the neo.

I have used the tent through out the mainland, Tasmania, nz and st America with two males over 6ft, spending upto 3 days straight due to poor weather and have had no issues with the small amount of overlap. Especially considering the taper of the sleeping bag makes this less o an issue.

Cheers

[ninjapuppet]

I just used my neoair xtherm in the middle of a himalayan winter up at 6000m. Got down colder than anything nz or Australia will ever get and I couldnt fault it.
I can recommend the OP to look at getting some xtherms. I have had 2 xtherms fit in a macpac Olympus wthout overlapping. The xtherms come in short, medium, regular and large and mine were the regular 180cm length ones.

Alternatively, 2 full sized rectangular mats would overlap abit, but as onestepmore pointed out: when you're tired after a long days hike, i dont think you'll care as much as you do while in the comfort of your home.