Original Mountain Marathon (OMM)
Looking to strike the right balance between warmth and weight is difficult when conditions on the OMM can vary between wet and wild at one extreme and decidedly chilly, even freezing, at the other. On cold mountain nights one wants to rest and sleep well.
OMM Sleeping Bags
The two PHD sleeping bags which have been chosen most frequently for the OMM are the Minimus and the Minim 400. The Minimus excels at saving weight and bulk in your pack, while the Minim 400 ensures secure warmth if the temperature dips.
The Minimus has been used below zero on many occasions, but mostly in competitions where only one or two nights camping were involved. The OMM can be a fully committing mountain race and under cold conditions the argument for extra comfort (Minim 400) is strong. The Ultra K, the lightest of all the PHD bags, is a third option, if down clothing is included in your kit list (See the notes below).
The basic figures for the standard models:
|S-bag||TOT (Min Temp)||Weight||Packed size|
Hght x Diam (cm)
|Minimus||5||41||465||16||21 x 13||255|
|Minim 400||-5||23||670||24||28 x 17||315|
|Ultra K||8||46||330||12||21 x 13||285|
- 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.
- LINERS: A liner will add to the insulation if you choose the Minimus or the Ultra K, but want more warmth. As always it is a trade-off between the extra weight and bulk and the warmth you gain (maybe 2C). Silk liners at 140gm probably give the best value.
- CLOTHING: Thermals (if you are taking them) and/or other clothing obviously help to keep you warm. If choosing the Minimus or the Ultra K, an Ultra Down Vest K at 150gm is an optional addition for minimal weight.
- FABRIC OPTIONS: The Minimus and Minim 400 come as standard with M1 outer fabric. MX and Drishell are the other optional outers for these two bags. MX is our lightest fabric and reduces the total weight by about 18gm. Drishell is highly wind/water resistant and adds about 40gm to the total weight.
- ZIPS: None of these bags has a zip. Zips are an option, but most competitors don't ask for one. A short zip with draft tube adds about 50gm (2oz): a full zip and tube adds about 110gm (4oz). Zips also add to the packed size.
- PACKED SIZE: PHD stuff sacs tend to be on the loose side. All these bags can be compressed further in your sac, particularly the Ultra K.
Figures for Fabric options:
|S-bag||Materials||TOT (Min Temp)||Weight||Packed size|
Hght x Diam (cm)
|Minimus||MX outer||5||41||440||15.5||21 x 13||275|
|Minimus||Drishell outer||5||41||505||18||21 x 13||285|
|Minim 400||MX outer||-5||23||645||23||28 x 17||336|
OMM Down Clothing Selection
The OMM weekend commits the racer to a quite considerable time at the evening campsite after the first day's racing. What's more, the clocks move back an hour at 2:00 a.m. on the Sunday morning, meaning an even longer period in camp before the chance to warm up on the second day of racing.
The use of down clothing as a layering system while in your sleeping bag and for wearing around camp is worth considering for ultimate weight saving and provision of warmth. Our ultralight range of clothing was designed with this need in mind. The Ultra Vest K weighs only 150gm, which is lighter than most T-shirts, yet it will provide real warmth down to approximately –5C. The Ultra Pullover K is for the same reasons another good option. At 230gm it's about half the weight and bulk of a conventional fleece jacket and 100% windproof as well. The Minimus range including the Minimus K Jacket, Minimus K Vest and Minimus K Pullover are also suitable for the OMM. Along with these our new Minimus down trousers and Minimus down socks will add considerably to the performance of your sleeping bag.
The next Original Mountain Marathon will take place on 28th & 29th October 2017 (50th anniversary year).
Photo: Eric Rayner