RAB’S MYTHIC 600 & MYTHIC ULTRA 360 SLEEPING BAGS WE CONSIDER TO BE ‘EXPERT USE’ BAGS WHEN IT COMES TO HIGH ALTITUDE CLIMBING, FITTING A SMALL NICHE THAT’S ONLY PRESENT AS THE OVERLAP OF SEVERAL OTHER FACTORS. WE’VE COME TO THIS AFTER SIGNIFICANT TIME DELVING INTO THE IDEA FROM SEEING IT IN USE 20 YEARS AGO BEFORE HIGH ALTITUDE CLIMBING BECAME WHAT IT IS TODAY.
IN GENERAL, RAB’S MYTHIC AND MYTHIC ULTRA BAGS ARE TOUTED AS 3 SEASON OR ‘EASY 4 SEASON’ BAGS FOR USE IN SCOTLAND AND THE ALPS, AND AT THAT LEVEL THERE’S LITTLE MORE TO BE SAID. BUT DEEP DOWN, ESPECIALLY WHEN YOU CONSIDER RAB’S INVOLVEMENT OVER DECADES OF EXPEDITION CLIMBING, BETWEEN THE LINES THOSE WHO KNOW, KNOW THERE’S MORE TO IT.
IN THE CONTEXT OF FEEDING THE RAT EXPEDITIONS THESE BAGS FIND A PLACE AS PART OF A GREATER SLEEPING SYSTEM THAT COMBINES WITH OTHER GEAR FOR A WAY TO CAMP AT VERY HIGH ALTITUDES THAT APPEARS LUDICROUS TO THE NORMAL OBSERVER AND WOULD PROBABLY GET YOU DENIED LEAVING BASECAMP ON AN INDUSTRIAL 8000m EXPEDITION WHERE THE OTHER ELEMENTS ARE NOT PRESENT. WE OFFER THIS HERE WITH A LARGE DOSE OF ‘AT YOUR OWN RISK’ AND ‘FOR INFORMATION PURPOSES ONLY’.
THESE USES ARE BASED ON THE EQUATION THAT 1800g OF INSULATED GEAR WILL GET YOU RELIABLY TO -25c, AN EQUATION THAT OVER THE LAST 5-6 YEARS HAS BEEN PUSHED BY THE AVAILABILITY OF HIGHER GRADES AND NANO-TREATED DOWN.
.
RAB MYTHIC 600 SLEEPING BAG
THIS IS A BAG DESIGNED FOR ALPINE USE. THOUGH VERY HIGH SPEC, IT’S NOT BRISTLING WITH OBVIOUS FEATURES AND IS EVEN COMPLAINED ABOUT THAT IT’S NOT AS BLINGED OUT AS SIMILARLY WEIGHTED BAGS, MISSING THE POINT THAT WHAT IS FORGONE IN COMPLEX FEATURES IS SUNK INTO INSULATION AND DESIGN NUANCE INSTEAD. SIMPLE IS THE GAME HERE, WITH A BAG INTENDED TO BE USED IN CRAMPED OR EXPOSED BIVYS WHERE YOU UNFURL IT, GET IN, CRANK IT DOWN AND WAIT TILL 3am SO YOU CAN START MAKING COFFEE.
WHAT MATTERS AT THIS LEVEL IS RELIABLE INSULATION THAT WON’T SHIFT, BAFFLES THAT SEAL OUT WIND AND SPINDRIFT, FABRIC THAT SHEDS BOTH AGAIN AND A SHAPE THAT MINIMIZES DEAD AIR. THE ‘-16c’ RATING IS ALPINISTS SPEAK FOR ‘-25c WITH ALL YOUR OTHER GEAR USED WITH IT AND EXPECTING TO WAKE AT 3am ANYWAY’*
YOU GET A 1/2 LENGTH ZIP BECAUSE THAT’S ALL YOU WILL NEED, OPENING BOTH DIRECTIONS FOR THE VERY REAL FUNCTION OF CLIPPING IN. THE NECK & FACE BAFFLES ARE VERY WELL EXECUTED WITH CINCH CORDS ON BOTH AND THE EXTERIOR BAFFLES ANGLING AWAY TO MINIMIZE FROST BUILD UP. THE LOWER HALF OF THE MYTHIC 600 IS SLIM BUT CONTRARY TO SOME REVIEWS (ALMOST ALL BY PEOPLE WHO HAVE NEVER ACTUALLY USED THESE BAGS) NOT RESTRICTIVELY SO – YOU TURN WITH THIS BAG, NOT INSIDE IT – AND IS VOLUMINOUS ENOUGH TO ACCEPT GLOVES, BATTERIES, GAS CANNISTERS etc. FOR THOSE PICKING UP WHAT WE ARE PUTTING DOWN HERE, THIS BAG WILL ACCOMMODATE HAVING A DOWN SUIT WORN INSIDE IT IF YOU ARE NORMAL SIZE, AND IS ABOUT THE LIMIT OF SUCH TECHNIQUE FOR MOST USERS (NOTE THAT NOT ALL DOWN SUITS ARE GOOD FOR THIS, AND THEY RELY ON HAVING SUFFICIENT VENTING TO GET BODY HEAT INTO THE BAG ITSELF).
AT 885g THIS BAG IS AT THE CURRENT VANGUARD OF WEIGHT:INSULATION RATIOS AND COULDN’T HAVE EXISTED A DECADE AGO. PACKING-WISE, DESPITE THE COMPLIMENTARY DRY BAG, THIS BAG REDUCES IMPRESSIVELY WHEN SHOVED HAND OVER FIST INTO A PACK THEN RELOFTS MERRILY AGAIN NEXT TIME IT’S PULLED OUT. UNLIKE SOME BAGS THAT HAVE VERY IMPERVIOUS FABRICS AND DON’T COMPRESS WELL (LOOKING AT YOU, S2S) RAB’S BAGS WORK WELL IN THE CONFINES OF A SMALL TENT AND A SENSE OF URGENCY.
ALL UP, THIS IS THE BAG WE ADVOCATE FOR K2 NORTH RIDGE-TYPE STUFF FOR THOSE CONFIDENT ENOUGH (AND TESTED ENOUGH) TO START USING ‘TWIGHT-GRADE’ TECHNIQUES.
.
RAB MYTHIC ULTRA 360 SLEEPING BAG
IF READING THE ABOVE REVIEW HAS YOU THINKING ‘YEAH, BEEN THERE’ THEN THERE’S ANOTHER LEVEL WAITING.
ONCE MASTERED, THE USE OF YOUR DOWN SUIT – A WEIGHT YOU WILL CARRYING REGARDLESS – AS PART OF YOUR SLEEPING SYSTEM OPENS UP FURTHER POSSIBILITIES ARGUABLY WORTH THE SAVING OF A FEW HUNDRED GRAMS, AND AT 280g LIGHTER (~30%) AND RATED INAPPROPRIATELY TO -8c USING A SYSTEM THAT ONLY MEASURES PART OF THE EQUATION, THE MYTHIC ULTRA 360 IS WHERE THE EDGE OF HIGH ALTITUDE SLEEPING SYSTEMS IS AT.
“-8c!?!?” YOU MAY SAY, SO WE WILL EXPLAIN.
A SLEEPING BAGS TEMPERATURE RATING IS MEASURED BY IT’S ABILITY TO INSULATE A BODY FROM HEAT LOSS VIA CONVECTION & CONDUCTION – INTO A COLD ENVIRONMENT BY EITHER CONTACT OR AIR MOVING PAST IT CREATING A PRESSURE DIFFERENTIAL. SOMEWHERE WITHIN YOU BAGS INSULATION IS THE POINT WHERE WARMTH OFF YOUR BODY MEETS COLD FROM OUTSIDE, THE COLDER IT IS THE CLOSER THAT IS TO YOU SO THE LESS OF THE BAGS INSULATION IS TRAPPING THE HEAT (ALSO WHY IT’S VITAL TO VENT BODY HEAT INTO THE BAG WHEN USING A DOWN SUIT COMBINATION). THE OTHER MAIN MECHANISM FOR HEAT LOSS IS RADIATION – UP TO 65% FROM THE HUMAN BODY APPARENTLY – AND THIS IS WHAT THE MYTHIC ULTRA ADDRESSES BY HAVING A REFLECTIVE TREATMENT INSIDE.
NOW, REFLECTIVE TREATMENTS HAVE BEEN AROUND FOR YEARS, BUT HAVE ALMOST ALWAYS BEEN MISUNDERSTOOD TO THE POINT OF BEING EFFECTIVELY GIMMICKS. BY IT’S VERY NATURE, SUPER-REFLECTIVE SURFACES ARE METALIZED, SO WHEN USED INCORRECTLY AS THEY USUALLY ARE, THEY ACTUALLY ACT MORE CONDUCTIVELY. TO WORK TO REDUCE HEAT LOSS, A REFLECTIVE SURFACE NEEDS TO BE BUFFERED FROM THE EFFECTS OF CONDUCTION OR CONVECTION ON EITHER SIDE, OTHERWISE THE GREATER EFFICIENCY OF THESE MECHANISMS OVERRIDE WHATEVER REFLECTIVITY MAY ACHEIVE. THIS MEANS FOR A REFLECTIVE SURFACE TO WORK IT NEEDS TO BE SANDWICHED BETWEEN LAYERS OF INSULATION – IN FRONT OF IT SO ANY REFLECTED RADIATION IS RETAINED, AND BEYOND IT SO THE RADIATION ISN’T CONDUCTED THROUGH. TO YOU THE CLIMBER THIS MEANS WHATEVER REFLECTIVE SURFACE BEING USED MUST HAVE DOWN BOTH SIDES OF IT – WHICH IS EXACTLY THE IDEA THE MYTHIC ULTRA 360 IS USING, AND CAN FURTHER BE BUILT UPON WITH A DOWN SUIT USED EFFECTIVELY INSIDE.
RAB’S MYTHIC ULTRA BAGS USE WHAT THEY CALL TILT WHICH IS A PROCESS OF APPLYING A HIGHLY REFLECTIVE COATING (TITANIUM) TO THE MATERIALS ON THE INSIDE OF THE BAG. FOR MATERIAL FREAKS WHO GET OFF ON ARAMIDS, AEROGEL, COMPOSITES, ULTRA HIGH MOLECULAR BLAH BLAH AND AEROSPACE INDUSTRY TRICKLE DOWN, THIS WILL BE EXCITING. WHAT TILT ACHEIVES IS A REFLECTIVE SURFACE IN FRONT OF 900fil DOWN SO IT HAS ENOUGH NORMAL INSULATION TO HARNESS THE EFFECTS OF REFLECTING RADIATION. BUT ONLY JUST.
USED NORMALLY A CLIMBER MIGHT SQUEEZE AN EXTRA 10-15% MORE TRAPPED HEAT OUT OF THE MYTHIC ULTRA’S 360g OF DOWN THAN USING A BAG OF THE SAME INSULATION PROPERTIES MINUS THE TILT WITCHCRAFT – RAB’S OWN BAGS WITH 400g OF DOWN AND NO TILT ALREADY RATE TO -7c (AN EXTRA 1c FOR 40g OF DOWN). BUT THAT’S WHERE THE EN STANDARD FOR TESTING INSULATION FAILS – IT ONLY MEASURES HEAT LOST THROUGH CONVECTION & CONDUCTION, NOT RADIATION.
WHEN PAIRED WITH A DOWN SUIT INSIDE TO MINIMIZE CONDUCTION (HEAT REACHING THE REFLECTIVE SURFACE) AND A WELL MANAGED TENT SPACE OUTSIZE TO MINIMIZE CONVECTION (HEAT SUCKED AWAY BY MOVING AIR), THE PROPERTIES OF RETAINING HEAT RADIATED FROM THE BODY START TO SOAR AND THOSE NUMBERS OF 30-65% START TO BE MORE REALISTIC.
DOES IT WORK? YES IT DOES, BUT WE KNEW THAT ALREADY FROM DABBLING YEARS AGO WITH USING SPACE BLANKETS INSIDE SLEEPING BAGS – RAB HAVE JUST DONE IT PROPERLY IN A WAY THAT CAN BE TAKEN TO HIGH ALTITUDE WITH THE CAVEATS OF ENOUGH FOOD, GOOD TENT DISCIPLINE, A SOLID INSULATING MAT UNDERNEATH AND THE RIGHT DOWN SUIT (WHICH INCLUDES RAB’S OWN) IN PLACE. IT’S IMPERATIVE THAT THE PRINCIPLES BE UNDERSTOOD BEFORE USING SOMEWHERE LIKE CAMP 3 ON K2, SO THEY CAN BE ADJUSTED DEPENDING ON THE SCENARIO.
AS FOR THE REST OF THE BAG; THE MYTHIC ULTRA IS TWEAKED IN EVERY WAY TO BE A TRUE ALPINE SLEEPING BAG. IF YOU THOUGHT THE MYTHIC 600 WAS REFINED, THEN THE ULTRA IS A STEP BEYOND THAT. A DOWN SUIT WILL FIT INSIDE PERFECTLY IF YOU’RE ANYTHING UP TO L SIZE – STATEMENTS ABOUT THIS BAG BEING ‘CLAUSTROPHOBIC’ ARE USUALLY LACKING ACTUAL EXPERIENCE WITH THE BAG, AND THE 360 HAS A HALFWAY ZIP LIKE ANY OTHER ALPINE BAG OFTEN WILL. IN TRUE ALPINE STYLE THIS IS A BAG YOU CAN SIT UP IN, AND PACKING-WISE THIS IT’S REMARKABLY COMPACT AND COULD FIT IN THE LID OF A PACK IF NEEDED. THE ZIPS, BAFFLING, CINCH CORDS AND FACE DESIGN ALL CONCURR WITH THE MYTHIC 600 REVIEWED ABOVE.
THE ONLY THING WE REALLY DISLIKE – AND IT’S CERTAINLY NOT ONLY THE 360 THAT HAS THIS – IS THE WAY THE BOTTOM OF THE DOUBLE SLIDER ZIP SEPERATES, MAKING IT INSANELY DIFFICULT TO RECONNECT WITH COLD HANDS, OR CRAMPED SPACE, OR WHEN THE BAGS TWISTED, ie ANY TIME IN REAL WORLD USE. AS FAR AS WE CAN SEE THERE’S NO REASON TO HAVE THIS AND MANY NOT TO, SO LIKE ALL OTHER TIMES WE COME ACROSS IT IT GETS SEWN TOGETHER SO THE ZIP ACTS AS IT SHOULD. UNLIKE SOME REVIEWS, WE THINK THE 360’s ZIP IS VERY GOD AND THE DOUBLE SERVES A VITAL FUNCTION – FIXING THIS WOULD GIVE THE BAG FULL MARKS FOR ALPINE USE IF IT HAPPENS.
BOTTOM LINE IS THE MYTHIC ULTRA 360 + DOWN SUIT GETS US TO THE OLD ADAGE OF 1800g GOING TO -25c, THEN GOES BEYOND THAT IN SIGNIFICANT NUMBERS BY HARNESSING PROPERTIES USUALLY LOST IN OTHER BAGS. ALONE THE BAG WOULD GO TO ABOUT -12c WITHOUT TOO MUCH CONCERN (AND WHERE ANY ATTEMPTS TO PUSH ALL THIS WOULD BE THE PLACE TO START), THEN THERE’S A LARGE SLICE OF THE TEMPERATURE AND ALTITUDE SPECTRUM BEFORE IT GETS TENUOUS. IF REAL HIGH ALTITUDE PERFORMANCE IS YOU THING AND YOU’VE WORKED ON ALL THE OTHER ASPECTS, THIS IS WHERE THE SORT OF WEIGHT SAVINGS THAT CAN MAKE A DIFFERENCE CAN BE FOUND.
.
.
*PROCEED AT YOUR OWN RISK. SERIOUS COLD IS NOT A JOKE AND THE IDEAS HERE REQUIRE PROGRESS OVER TIME TO MAKE TYPE I FUN. MECHANISMS OF HEAT LOSS ARE BASED ON PRODUCING HEAT IN THE FIRST PLACE, ie KCALS, A SUBJECT COVERED FURTHER HERE
