The North Face Propel Loft

Hi Richard-

We’re testing the ’06 model (with the zippered footbox) right now and will be publishing a full review in the Spring.

I own an earlier model. Its double layer loft is approximately 2″ (1″ single layer). The insulation is very evenly distributed due to their welded construction.

Sorry, but I don’t want to spill too many other observations about the bag right now with a full review pending. I will say that based on field experience, loft measurements, and bag construction, I think their 40 degree rating is overly optimistic.

Cheers,

-Mike

Mike-Thank you for the prompt response.

Richard,

Based on how TNF rates their synthetic bags vs. the tested EN 13537 Lower Limits, I would guess that the Propel is more of a 50F bag. What do your numbers say for 1″ of Delta loft?

I did a fairly detailed analysis for one of the BPL forum subscribers. His ensemble included wearing long underwear, a Cocoon top/bottom, an insulated hat, using a Nitelight pad, and a bivy. The combination came out to a 42F for a Comfort Limit temp.

I didn’t analyze the bag by itself so as to not infringe on the Propel report M. Martin is going to publish in the spring.

>> I didn’t analyze the bag by itself so as to not infringe on the Propel report M. Martin is going to publish in the spring.

Thanks, Richard — very thoughtful of you.

But…

It’s not my intention to stifle a good exchange of information on these forums. I encourage you or anyone else to post their observations. Besides, our policy is not to provide temperature ratings in our bag reviews. So, any forum discussion on the subject will supplement the review.

btw, thank you for your forum contributions. Your various heat loss posts are an asset to BPL.

Best Regards,

-Mike Martin

Hi

I’ve owned an 05 Propel for ages. In summer it’s fine on it’s own. 2 season is ok wearing base layers & in bivy. Winter I had a Rab Top Bag inside, fleece base layers, hat and balaclave, in my bivy and was fine.

To be more specific my Winter example was at 0 degrees Celsius = 32 F, out of the wind, under pine trees and on a GossamerGear ThinLight 3/8″ plus BMW TorsoLite.

I’m guessing you guys mean 2 layers for lying the bag over you and not getting in. Can’t say I’ve ever tried that.