Cycling UK Forum

The Tensors were about £140 when we got ours - but stuff has gone up a lot! I would happily use them year round now. I class -3 as three season - as on our 3 months + tours we start late April, and have routinely had overnight temperatures of -4 or below in the first week or so in Europe. As we will be riding in warm climes for most of the summer we only take summer kit (the "Insulated" bit of our mats being the only concession to winter), using Vango Venom 200 sleeping bags which have a "limit" rating of +5, but they are comfortable down to 0 with a mid-layer jacket around the foot area and bedsocks, and in that mode tolerable down to -5.

PH wrote: ↑6 Jul 2022, 12:22pm

mxg01 wrote: ↑6 Jul 2022, 9:55am Given your constraints I think you are looking at something like the Alpkit Dirtbag or Dozer.

As posted upthread I have a Dozer, I've also slept on a Dirtbag while visiting friends (Just on the lounge floor, so no camping experience, let alone winter)
They are very different, Dirtbag is half the weight and half the R value (3.5 V's 6.8 ) That's down to the same rating as a standard Thermarest. We're all different, but I'm certainly not warm enough on such a mat, even on some Spring or Autumn nights. Dirtbag is certainly a comfortable mat, but I think warmth wise it isn't going to be much of an improvement on what Sweep already has.

Having a actually managed eventually to see a dirtbag i think you are right. Maybe a bit thicker than my old thermarest and maybe more stuff inside it, but not different enough to make it worth buying.
I did ask the bod in the alpkit shop if they did something that was good for winter, and it seemed not really.
Still, mini heatwave building, time to sort.
Dozer didn't seem to be able to fold in half before rolling.

Sweep wrote: ↑7 Jul 2022, 5:22pm Dozer didn't seem to be able to fold in half before rolling.

I'd say that was right, at least certainly not easily. It's out on loan so I can't test it.

There is a trick to folding them lengthways. Firstly, get as much air out by rolling normally, then close the valve, unroll, fold and roll. As you get towards the end open the valve to get rid of the last bit of air.

Sweep wrote: ↑6 Jul 2022, 9:26am I thought I made it pretty clear in my initial question that I wasn't interested in the likes of the NeoAir.

Based on willem jongman's posts in that thread and here - viewtopic.php?p=1602207#p1602207, it appears that NeoAir models are not all ultralight. The outer fabric of the ultralight NeoAirs is 30 denier (and the Nemo Tensor mentioned above is 20 denier), but the NeoAir Topo Luxe is 50 denier. I wonder if a fabric with a higher denier results in stronger bonds, with less likelihood of failure of the internal baffles and a longer lifespan.

slowster wrote: ↑8 Jul 2022, 10:17am I wonder if a fabric with a higher denier results in stronger bonds, with less likelihood of failure of the internal baffles and a longer lifespan.

I'm going to guess no. That's based on two things:
- My two Exped mats failed in the same way after similar usage, one heavyweight Downmat the other an Ultralight Synmat.
- I used to work with heavier but similar materials, it's PVC or some other plastic, on either side of a woven membrane, it's the interface between the PVC and membrane that parts. If you can get a piece to lift, you can pull the joint apart very easily, despite it being incredibly strong in all other directions (I must have pulled miles of it apart, you run a test weld on off-cuts before every job). The heaviest and lightest materials I've worked with, all lift as easily. Everything is designed to prevent an initial lift - hemmed edges, bolted fittings, a closed shape weld if you have to tooling, or if nothing else a T weld (Though that then has two ends to deal with). I've been saying this since the mats became available, I don't know how you can weld a tube like that, I think the answer is you can't without a high failure rate.
I don't know how the cell/button design mats are made, it can't be the same method as above, they wouldn't last.

PH wrote: ↑8 Jul 2022, 12:14pm it's the interface between the PVC and membrane that parts. If you can get a piece to lift, you can pull the joint apart very easily, despite it being incredibly strong in all other directions (I must have pulled miles of it apart, you run a test weld on off-cuts before every job). The heaviest and lightest materials I've worked with, all lift as easily. Everything is designed to prevent an initial lift - hemmed edges, bolted fittings, a closed shape weld if you have to tooling, or if nothing else a T weld (Though that then has two ends to deal with). I've been saying this since the mats became available, I don't know how you can weld a tube like that, I think the answer is you can't without a high failure rate.
I don't know how the cell/button design mats are made, it can't be the same method as above, they wouldn't last.

That is interesting - so it's not the quality of the weld that is decisive, because it is the lamination/bond of the PVC and the membrane at the weld which fails, not the weld itself. In that case I wonder if the button/cell design simply reduces the probablity of failure by having a much smaller percentage of the fabric that is welded and under stress compared with channel baffles. I guess it might then be as simple as failure being say ten times less likely, simply because the area of welded fabric is ten times less.

By cell/button design I take it you mean something like the following?

https://www.addnature.co.uk/sea-to-summ ... gid=233509

slowster wrote: ↑8 Jul 2022, 1:55pm By cell/button design I take it you mean something like the following?

https://www.addnature.co.uk/sea-to-summ ... gid=233509

Yes. I don't know if it has a proper term, I used that because it looks similar to the furniture like that which is often called buttoned, though the correct name for that is Tufted.

Minus 3 in April this year was fine with secondhand classic thermarest £30 on top of Lidl closed cell mat £6 underneath two, 2 season Mountain Equipment down sleeping bags, Dewline inside Lightline from mountain marathon days. Plus sleepingwear, with option of extra Helly Hansen thermal leggings, not needed.

Not the lightest solution, and the foam mat is also bulky, but I know I'll always be warm enough, and a thermarest puncture would not be disastrous.

matthewslack wrote: ↑18 Jul 2022, 11:51am Minus 3 in April this year was fine with secondhand classic thermarest £30 on top of Lidl closed cell mat £6 underneath two, 2 season Mountain Equipment down sleeping bags, Dewline inside Lightline from mountain marathon days. Plus sleepingwear, with option of extra Helly Hansen thermal leggings, not needed.

Minor point of order, the Lightline is significantly warmer than the Dewline and more of a 3-4 season bag (those are my two bags, I use the 300g fill Dewline as a summer bag and the 550g fill Lightline for everything else, including one night when it was okay in a snowcave where a bottle of juice froze solid)

well, reporting back - eventually.

In the end I went for this:

https://www.outdooraction.co.uk/vango-t ... mat-p11152

£44.

Have also seen at Cotswold for about £60 I think.


Curiously, it says it has an R value of 4 on the bag but 5.7 on the tag.

Vango assured me in answer to an email query that the higher R value is the correct one.

Been testing it in current cold snap.

At first with a cheapo Z-fold solid mat underneath - all fine.

Then another more recent day without the added mat underneath when it was so cold that condensation froze on the inner tent. Maybe a bit more cold from the ground but not so sleep really disturbed.

So rather pleased with it.

It is of course a bit heavier than some of the minimalist wonders (doesn't bother me) but of course somewhat cheaper.

Obvs not a long term test but feels quite well made.

I like the valve system on it.

Feel free anyone to ask any questions about it.

thanks for the input above.