Western Mountaineering Flash Pants vs Montbell UL Down Inner Pants

Talked to WM direct about these 2 pairs of pants.
The Flash pants are 6oz and have 2oz of fill in a medium.
The Flight Pants are 10.5oz with 3oz of fill in a medium.

Medium waist is 32-34 inches.

I've used the MB UL inner Down Pants. They are fantastic for the weight. I sold them to look for some pants that were full zip and now it looks like the WM Flight pants are in the lead over the MB UL Tech pants.

I don't know much about these pants, but I do have the Mont-Bell UL Down Inners and love them. They do have a fly that could be eliminated to save a little weight, perhaps WM did that. I personally like the "sweat-pant" style minimalist approach.

Hello Ty,

It looks like we both posted the almost exact same thread today. I too am comparing the Flash pants and the Down Inner Pants.
I'd be curious to see what anyone has to say about the WM Flash pants.
It sounds like most people have the Down Inner pants and really like them. I'm also not seeing a lot of info on the Flash pants.

What about the BPL cocoon pants?

Hi Doug,

I did consider the BPL Cocoon Pants as well as the Integral Designs PLQ Pants. I'm leaning more to down insulation as the pants would be strictly for insulation in low to no activity situations and, the more I read, the more I find that synthetic really blows out after being compressed over time (more so than down).
Plus, the Cocoon pants are more expensive, a bit heavier and out of stock. :-/

I ordered both pairs of pants.

I have a trip coming up in three weeks and wanted some lower body insulation. Since information on the WM pants was so scarce I decided to compare the two firsthand. As of now I am leaning towards the WM based on the higher fill-power down, the lighter weight and the cheaper price. . .not to difficult of a decision.

Hello Ty,

I'd love to hear what you think when you get them both in. Where did you order the WM Flash pants from? Backcountry Gear?

Adam

I ordered the WM pants from Backcountry Gear. The only other place I could find them was Bent Gate Mountaineering and they only had XS and S in stock. (Is the climbing community already turned on to this item? It's difficult to imagine the ultra-lighters being beaten to the punch on new gear).

I'll be happy to share my thoughts. Other than the reasons I listed above for leaning towards the WM pants is the quality of WM. I do own a Montbell piece (Thermawrap Jacket) and have another in the mail (Extreme Light Down Jacket) so I don't question their quality in the least, but WM quality has few equals…but, in blatant contradiction to that statement, I'm sure any difference would be negligible.

WM products are also made in Canada versus China. That could be a factor in some people's decision.

Adam,

The pants came this week. I had intended to write up a comparison but I'm a week from finals and then I'll be on the trip for which I purchased then for another two weeks. If you are looking to purchase them soon I could put up some bullet points or PM me with your number and I could give you some more thorough thoughts and answer questions with the products in hand.

Hi Ty,

I appreciate it!
I ended up ordering the WM Flash pants from BCG after they came up on the WM site, and I did some more research on other options.
Could you maybe post some initial impressions?
How's sizing? Are they bulky? What's your opinion on warmth to weight, etc?
Good luck with finals! And enjoy your trip.

Take care,
Adam

One downside I can see, based on looking at the photos and description of each pair of pants, is that the Montbell has a full zip, whereas the WM Flash appear to just be pull-on's.

Just a quick comparison.

Objective.

The inseam on the MB is 3.5 inches longer.

MB has a zipper fly. WM nothing.

MB has circumferential drawstring waist w/elastic.
WM has elastic waste. Ribbon belt only on anterior 5" of waistband.

MB has relaxed cuffs with an elastic band and access to the band so that the cuffs can be cinched up. No cordlock is included. This would have to be supplied or a knot tied in the band to get the cuffs tightened around the ankles.

WM ankle cuffs are elastic. They fit snugly around the ankle. There is no adjustment.

MB has quilted sewn-through contruction.
WM has sewn-through construction with larger down chambers.

MB is made from the same material throughout.
WM has more durable material in the seat.

Fill Power
MB 800 fill-power.
WM 850 fill-power.

Fill Power
MB fill weight is 2.0 oz.
WM fill weight ??

Total weight:
MB – 6.8 (for M)
WM – 6.5

The WM are made in the USA for it's worth.

Subjective.

I think the waistband of the WM will be more comfortable without having a drawstring.

I would prefer to have the variable closure ankle cuff of the MB. If find this especially useful if I were to use these on trail.

The inseam length is certainly something to keep in mind.

I have decided on keeping the WM. The inseam fits me fine, they are better suited to my purpose and I believe that they are warmer.

My purpose for these pants is simple: camp/sleep wear. I am a meticulous caretaker of my gear but I do like the reinforced seat. Bear in mind this is not heavy material, just a little more abrasion resistant. It doesn't look as scared of pine-needles and cactus spines as does the shell material of either pant. It's hard to argue that this is extraneous weight since the WM are lighter than the MB.

I would assume a fill weight of 2 oz with the WM–I may have read that on a previous post. There is a minimal increase in the fill-power of the MW. I like this, but of its own would not be a deciding factor. There is more loft in the WM. Since fill wt. is equivalent I think the difference in loft can be attributed to construction. The sewn-through baffles (yes, I know they are not really baffles) of the WM are roughly 3.5" apart on the vertical and even longer than that on the horizontal. (As an aside, the baffles at the anterior knee peak centrally at about 5.5-6" and taper laterally to around 4" in an effort to provide some semblance of articulation). I didn't measure the quilted squares on the MB but I'd estimate them to be 2-2.25". So the baffles of the WM have greater depth and are less restrictive to loft. The WMs down chambers could handle a little bit more down, but they are in no way under filled.

I was mistaken in the above message. The MB quilted sauare are about 3.25". The vertical height of the WM baffles is rougly 3.75". It doesn't seem like a lot, but the allowance of loft is still significant.

Ty-
What size did you get? They don't show any sizing charts, especially for a unisex item.

Does anyone know how a medium in women's would relate to unisex sizing? I'm thinking it is based on a man's size.

I have a size medium and they fit fine. My waist is 32-34ish. I'm sure that my waist size is at the high end of what the medium is recommended for but the elastic waist still gives me a comfortable fit.

The Western Mountaineering webpage finally has some info up on these pants.