While modern cams or “active protection” has really changed the game when it comes to nuts and stoppers, there still exists multiple applications for “passive protection.” Though there are no terrible stopper designs, we found that some designs work best for specific cracks and fissures, in addition to those that perform best on textured rock or other orientations. The article below describes how we tested each set of stoppers and therefore determined how to best utilize each individual set.
Flared Cracks and Pin Scars
If you climb in very traditional places such as Yosemite National Park, where you'll encounter smooth glacial polished granite along with interesting, flared cracks and fissures along with pin scars left behind from before the push for clean protection, then you'll want to consider multiple sets of offset stoppers. Nut placements and constrictions exist on nearly every climb, whether you're seeking shade on the FiFi Buttress or aid climbing on El Capitan.
In order to properly test placements, we started by placing nuts from the ground so that we could assess how easily the stoppers could be slotted into place, whether or not the wire could support the nut itself or if it felt floppy, and finally whether or not the nut had a good “bite” into the rock due to a strategically placed groove. After our primary assessment, we went climbing, stopping to place and weight the stoppers with body weight before deciding if they could support a fall. Next up, we took the whip, and noted whether or not the nut shifted in placement or was notably difficult to clean. Offset stoppers like the DMM Alloy Offset and the Black Diamond Offset were the right set of stoppers for the job, easily slotting into the bottom of pin scars and flaring cracks, sometimes offering a better placement than offset cams.
Parallel Cracks
Though we often prefer modern cams in parallel-sided cracks, especially with the new cams that feature four lobes to almost guarantee grip on both sides, especially on granite and other bomber rock types, there are still those stoppers that offer the best performance on parallel-sided cracks.
Our testing plan was similar to that of our flared cracks and pin scar assessment where we noted our primary observations from placements on the ground, determining how easy the stopper was to place, whether or not we could easily shift the placement, and how easy it was to clean. Next up, we set off climbing on a route until we found a nut placement, then we weighted the nut with our body weight, before deciding whether or not the placement could support a fall. We then took the whip, afterwards noting the ease of cleaning in addition to whether or not the nut shifted. Stoppers that performed best in this metric were similar to the Black Diamond Stopper, though we realize that most climbers will select a cam instead of a stopper in most cases. While offset and curved stoppers don't perform the best on parallel-sided cracks, they can often still hold a body weight placement if you're in a pinch.
Performance in Textured Rock
Climbing areas such as Joshua Tree and Cochise Stronghold often feature a very textured granite, often with discontinuous crack systems that are filled with chunks and crystals that can create some tricky placements for cams, but allow for enough constriction that you're more confident in a stopper placement to protect a fall.
In order to test this metric, we set off climbing in locations that are best known for their textured rock as opposed to smooth sandstone or glacial polished rock. We noted the overall design of each stopper, especially the groove design that could offer a better “bite” in textured stone. We identified the best designs suited for textured cracks and fissures in addition to cracks that lacked uniform “splitter” shape that took a stopper placement better than a cam. Finally, we took some falls and noted how easy each stopper could be cleaned.
Ease of Cleaning
This testing metric was rather simple. Our testing team would simply place stoppers in various cracks and fissures with a variety of shapes and sizes, before testing each placement passively from the ground, under body weight, and finally after a fall. We noted which stopper placements were easiest to clean versus those that became a “fixed” piece of protection or those that took a few more whacks from the nut tool in order to wiggle out of a good placement. This is often where modern cams shine, as most climbers simply want to engage a trigger to remove a piece of protection, especially when pushing a route in a day. Stoppers, especially those that feature an offset design or brass construction, can be more difficult to remove, often requiring more time, to wiggle out from a good placement in good stone.
Durability
There are a variety of stopper designs available on the market, some far more durable than another. Some times climbers will sacrifice some durability for a niche design that comes in handy on difficult alpine routes, aid climbs on El Capitan, or tricky single pitch granite. For this metric, we carefully evaluated the nuts themselves along with the wires that held them together. After each testing fall, we determined which stoppers featured a more durable construction and those that trended towards wires that bend and curve in the direction of fall. We also noted the designs that were prone to kinked wires after jerking the nut in the upward direction when trying to whip the nut out of a constricting placement. Luckily, we never had any stoppers fail under body weight or a significant fall during our extensive testing period nor did the kinked wires fray to the point of absolute failure.
Use in Other Orientations
For use in other orientations, our testing team identified the stoppers ability to be placed along various axis. While most nuts perform best with the narrow axis facing outwards, allowing the wider axis to contact the rock, there are some designs that are versatile enough to be placed in both axis. Again, our testing team placed stoppers from the ground in various cracks and fissures in order to evaluate the stopper designs that were versatile enough to be placed in both axis, and those that were not.
Just for fun, we also noted the best stopper designs that could be used as a piece of aid attachment point for niche applications like on machine heads or rivet ladders. We also noted those designs that allowed the nut to slide along the wire to clasp onto cam trigger wires to help in removing an over-camed or buried placement.