MEC Reflex

Just a quick added note that if Richard N. is out there, I'd appreciate your thoughts as I do calculate clo values for my clothing (to the best of my ability), and you seem to have knowledge of this jacket.

Derek,

The MEC Reflex has an Iclo of ~7.91. It will keep the average person, doing camp chores, thermo-neutral down to -23F. It is a quality constructed garment with an athletic cut. I found no issue with hood fit when I tested it. Besides the two obvious circumference adjustments in front, there is an additional volume adjustment bungee hidden by a material flap on the back of the hood. Behind the zipper there is a heavy artificial suede flap (not light polyester like the rest of the garment). The flap is not insulated but it effectively blocks the wind and does not appreciably effect the garment's warmth.

ive only tried it in store … i like it alot …. super warm and puffay, it has a light shell and a lot of down

its surprising that it doesnt get more attention here as it has the most down of for the price and weight of any garment i know …

its not the perfect climbing jacket which id be looking for … but it seems to be to be the perfect deep winter UL backpacking jacket …

and its fairly cheap … just waiting for a mec clearence sale on it ;)

Eric, I've overlooked this jacket because it appeared to be a heavy, sewn through piece with little to recommend it.

But, if Richard is correct, it appears to be insanely warm… can anyone confirm the amount of fill? 15oz is a LOT… how about the pockets- are they insulated? Is the hood helmet compatible (I know it is not meant as a belay jacket, but I'd use it for one on occasion).

mike … i was able to fit a helmet under when i tried it on depends how big yr head is i guess … cant remeber about the pockets, i never use em anyways

the reflex uses a 15D shell and has minimal features … i assume the rest of the weight is all down …

the best bet would be to try one on at mec or post a question on the ask/answer for the product

my bet is that richard's testing includes thermal measurements so id go with his numbers … -23F is an awesome temp for camp for a 26 oz jacket … and at $265 can a good deal

im on the lookout for a suppah puffaay … just depends how cheap the EB FAs get after xmas i guess …. the extra 8-10 oz you save with a reflex is a lot of fuel for melting snow though

http://www.mec.ca/Products/product_detail.jsp?PRODUCT%3C%3Eprd_id=845524442630551&FOLDER%3C%3Efolder_id=2534374302699049

It seems hard to believe that this jacket really has 15oz of down. That's more down that a lot of 20F rated sleeping bags. I could be wrong, it just sounds suspiciously high.

It is a baffled design with insulated pockets (all of the down is on the outside). I tested the hood with a Petzel Meteor II climbing helmet and it fit over it. The fabric is only 15 denier polyester and there is not a double zip for harness access; the design is not optimized for belay use.

Thanks very much for all the replies. I am not a climber so belay features are less important to me. I guess I should give this jacket a serious look then! At this price, it is a fantastic deal – shipping and duties are always a killer ordering from the US.

The other advantage is that I might not need to spend as much on a winter bag. This will be my first year of winter camping. Let's say I have the MEC Reflex, Montbell UL Inner pants, Thermarest 1.5" pad + a Ridgerest underneath … how much bag would I need to be toasty at -30C/-22F, and alive at -40C/-40F? Some rough guessing based on this chart leads me to think maybe I could get away with a -5C/20F bag or maybe -10C/15F, is that possible? I could have my calculations messed up though, as I'm not sure how much total clo I'm getting from the pad vs. the bag.

Bag size is a big factor in estimating your total system insulation value. I assume you are using a sleeping bag like the MB SS that gently encompasses your girth both with and without supplemental clothing insulation. I also assume your 1 1/2" Thermarest is the old un-cored open cell version.

The garments you defined and a 10F EN 13537 rated bag is required to achieve a Comfort rating (thermo-neutrality) at -22F; this equates to a survival rating of -68F. Your estimates were very close; good analysis.

Richard, thank you very much.

I’d really like to understand why this is the case. I’ve been scouring your old posts for clues. I’d appreciate if I could try to understand your reasoning behind arriving at these figures, and you could offer any correctives needed so that I can learn to work these questions out myself. Since I am the OP on this thread, I see no one who would be bothered by this kind of slide into nerdiness, and maybe there are some who’d be interested too…

So, here is where I’ve landed so far. To achieve an EN 13537 Comfort rating at -22F/-30C, I need a sleep system that can deliver ~2.04 m2K/W (rough extrapolation based on this chart)/0.16 = 12.75 Tclo (including base layers providing 0.55 Tclo of insulation).

To calculate the insulation value of the bag needed to complement the clothing system I mentioned, I need to add up the Tclo of the other layers and pads, and subtract that from this number.

The insulation value provided by the Reflex jacket is 7.91 Iclo x 0.545 (percentage of body area covered) x 0.65 (percentage of jacket area not crushed by being under me, assuming I am a back sleeper) = 2.80 Tclo

Insulation value of MB UL pants is 1.78 Iclo x 0.43 (% body area) x 0.65 (% not crushed) = 0.50 Tclo

Insulation value of pad combination is 6.2R x 1.14 = 7.07 Iclo x 0.35 (% of body area covered by pad, assuming back sleep) = 2.47 Tclo

2.80 + 0.50 + 2.47 = 5.77 Tclo (insulation provided by jacket, pants, and pads)

12.75 – 5.77 = 6.98 Tclo (insulation provided by sleeping bag)

Because 35% of the surface area of the bag will be crushed under my body, this number represents only 65% of the bag’s Iclo. So, I need to calculate 6.98/0.65 = 10.74 Iclo (intrinsic insulation value of sleeping bag).

Again, according to the EN ratings chart linked above, a bag with this Iclo level would have a metric R value of 10.74 x 0.16 = 1.72 m2K/W, which amounts to an EN 13537 Comfort rating of -20C/-4F.

You specified that I would only need a 10F bag for those temps, so obviously my calculations are off by 14F. Could this number be made up by accounting for factors I haven’t taken into consideration, such as trapped air, or the minimal insulation value provided by the crushed bag and garments, or something else I’ve missed? Or maybe I’ve made an error in my calculations? I’m pretty new to this, and not a mathematician by any means, so it’s entirely possible.

I would really appreciate if you could take the time to point out any mistakes I’ve made here, so I can learn to address these types of questions on my own, and know how to do this for the future. I’ve appreciated enormously what I’ve learned from your posts so far.

derek ..assuming sufficient ground insulation i dont see why you can't just use the jacket as a tight blanket in yr bag, thus not wasting the crushed down

in fact, with the prevalence of BPLers who use quilts for this very purpose, i dont see why more people dont do this rather than wear the jackets

this of course has the benefit of having all yr arms next to yr body for the warmth

also note that yr setup with a reflex seems to be the perfect system … camp down to -23F … then sleep in comfort down to -22F …and youll survive anything short of the south pole in a worst case situation

Derek,

For quick estimation work I consider our conclusions to be in the estimation error range. I suspect the differece is just the culmination of multiple estimation value differences. For exmple for your very first calculation you determined you needed 2.04 m2K/W for -4F.

I started by calculating the m2K/W neeeded to achieve your target comfort temp of -22F; which is 1.71. I then calculated the m2K/W provided by the down clothing. I then subtracted this from the first number to see what m2K/W is required for the bag.

I will packing for a trip most of tomorrow and then will be traveling until after Thanksgiving. It will probably quite a while before I will have time to work on this problem again.

Thanks Richard, that clears up a lot of things for me.

Eric, I agree that layering the jacket is probably a better strategy. I'm used to using a quilt for the rest of the year, and this is, as you say, a similar idea. I'll have to try it both ways this winter and see what works.

Thanks to everyone for their help. I'll be off to try out the Reflex next week, and will post my thoughts when I do.

Bump. Tis the season.