I became a Montbell sleeping bag convert after buying my first stretchy baffle bag nearly a decade ago. I simply love sleeping outside and would choose a tent and sleeping bag over a bedroom almost any day, but the traditional, constrictive mummy bags I grew up with often left me feeling claustrophobic as I inevitably tried to twist, turn and roll like I naturally want to do. I bought a new Montbell 800 fill down bag rated to 40 F. back in April because I wanted a light, compressible bag for warm season bike packing and long-distance summer backpacking where weight and packability are mandatory, but I also knew I couldn’t live without the flexible construction of a Montbell bag’s “Super Spiral Stretch System.”  The company achieves this by integrating a woven fabric at 45 degrees to most major seam lines, making the bag more fluid. And then they top that off with elasticized thread in the stitch to create small “gathers” in the quilting. Which means you can squirm, stretch and flex without busting out a zipper. At 1lb. and 4 oz., the bag stows nicely into small pack spaces on your bike or back. MSRP: $229.00. Montbell.us. //