Mourne Mountain Marathon

Mourne mountain marathon The Mourne Mountain Marathon is a two-day event held in Northern Ireland. Teams of two people must be totally self-sufficient for the two days. Expect early autumn mountain conditions, but, as always, you can encounter tough-going mountain weather. A good night's sleep can make all the difference to your results.

Sleeping Bag choice

The two PHD sleeping bags most suitable for the Mourne Mountain Marathon are the Ultra K and the Minimus K. Both are very lightweight. The Ultra K excels at saving weight and bulk in your pack, while the Minimus provides extra warmth. Otherwise, the Superlight option on our Design Your Own Sleeping Bag site allows you to create a bag of exceptionally low weight to your own specifications.

For mountain competitions, particularly where only one or two night's camping are involved, there is a strong incentive to travel as light as possible. Combining the Ultra K sleeping bag with down clothing - such as our Wafer or WaferLite gear - is another potential option to secure a good night's sleep.

The basic figures for the standard models:

S-bag TOT (Min Temp) Weight Packed size
Hght x Diam (cm)
F gm oz 
Minimus K 5 41 380 13 21 x 13
Ultra K 8 46 330 12 21 x 13

Additional points:

  1. TEMPERATURE RATING: Put simply, these are the temperatures at which you should be able to get a night's sleep in normal circumstances. For fuller details about the TOT rating see this Technical Briefing.
  2. LINERS: A liner will add to the insulation, but as always there is a trade-off between the extra weight and bulk, and the warmth you gain. Silk liners add roughly 2°C but only weigh around 140g so they’re a popular choice. If you’re especially concerned about cold, our K Series Filler Bag is 100g heavier than that but will add 10°C.
  3. CLOTHING: Thermals (if you are taking them) and/or other clothing obviously help to keep you warm. For example, an outfit of Wafer clothing will give a 5°C boost to the temperature ratings of our bags.
  4. FABRIC OPTIONS: Both bags come as standard with MX outer fabric - a mini-ripstop nylon with excellent tear-strength - but are also available in Ultrashell, which is highly wind/water resistant but only adds about 18g to the total weight.
  5. ZIPS: These bags are designed to work without zips, to keep weight down. Zips are an option, but most competitors don't ask for one. A short zip with draft tube adds about 50g (2oz); a full zip and tube adds about 110g (4oz). Zips also add to the packed size.
  6. PACKED SIZE: PHD stuff sacs tend to be on the loose side. All these bags can be compressed further in your pack, particularly the Ultra K.

Figures for Fabric options:

S-bag Materials TOT (Min Temp) Weight Packed size
Hght x Diam (cm)
F gm oz 
Minimus K Ultrashell outer 5 41 398 14 21 x 13
Minim Ultra K Ultrashell outer 8 46 348 12 21 x 13

Clothing selection

At the campsite, at the end of a day's racing, the drop in temperature can be very noticeable, making warm, compressible and lightweight clothing extremely useful.

The use of down clothing - such as our Wafer clothing - as part of a Sleep System with your sleeping bag and for wearing around camp is worth considering for ultimate weight saving and provision of warmth. The Wafer Jacket weighs only 190g - a lot less than a standard fleece - yet it's windproof and provides real warmth down to freezing point. To save even more weight, there's our WaferLite range: the lightest down tops in the world, which are warm down to around 5°C. If you're more concerned about getting cold though, the Ultra Pullover goes even lower - down to -5°C - but is still only 225g.

It can get damp out there, and synthetic insulation tends to fare better than down in the wet. Carrying waterproof clothing is compulsory, so you should be able to avoid saturation, but if you prefer the more failsafe, less moisture-sensitive option of synthetic gear, then our Sigma gear is well worth a look.

When layering clothing inside your sleeping bag, make sure you don't neglect your feet! A pair of Wafer Socks weighs just 45g but makes a huge difference.

The next Mourne Mountain Marathon takes place 18 to 19 September 2021:

Photo: Anthony Fryer