Discussion with photo at backpackinglight
From the makers of ursack.com:
August 18, 2006
It pains me to have to write this, because we thought we had come up with a nearly perfect bear proof product. Although the Ursack Hybrid has done extremely well, we have learned from an incident in Yosemite that the bottom of the bag may be vulnerable. We think it may be because the Vectran fabric has fewer filaments per inch than the Spectra we previously used (and is not currently available because of military demand). Coincidentally, the new Ursacks now shipping are made with a beefier Vectran that was not available before. We hope that solves the problem. Unfortunately, there is no really scientific way to test it. The Vectran we have been using was successfully tested by us at the zoo and by the SEKI rangers in the wild. Only real world camper experience tells the tale. Regardless, we stand 100% behind our warranty.
We are always searching for ways to make Ursack better, and are working on new ideas now to address the possible vulnerability of the Vectran bag. Until we get to the end of this summer season, there is no accurate way to determine if this vulnerability is a serious problem or not. Lots of our previous customers have bought the aluminum liner to add to their Spectra bags, and there have been no reports of any problems with that version of the hybrid.
What is really critical is the willingness of the Sierra rangers (and SIBBG in particular) to keep working with us. We all know that no bear canister is perfect. Just this week, I got an email from a park service employee in Tuolomne Meadows who reported the failure of a well known hard sided canister (NOT a Bear Vault) being used by a back country wilderness crew. I won't give the brand name because I don't have first hand knowledge, and would ask that all of you use the same restraint in reporting failures of any product. If SIBBG revokes the use of any product without the possibility of approving improved versions, it is the kiss of death because the Sierra is such a huge part of the market. We want to be sure that any decisions are made on verifiable facts, not rumors.
I welcome your input on ways to improve Ursack. You can email me directly at email@example.com.
posted by Tom at 4:09 PM