stix wrote:Spinners seem to be occuring way more consistently in muir than in other regions of the red. Victory whips do seem "unecessary" but haven't been cause for concern in the past. Maybe there's another reason we are having to constantly tighten bolts on brand new routes??
First off, I wouldn't necessarily agree that there are more spinners in Muir than elsewhere. There are no stats to back up claims that any one place in the Red has more spinners than another.
Here are a few facts that CAN be confirmed:
1. The bolts used at Muir are the same, or essentially the same, as those used elsewhere in the Red. (Rawl 5-piece 1/2" or Dynabolt Gold 1/2")
2. These bolts are being tightened with the recommended torque for bolting into soft concrete, since no recommendations are given for Corbin sandstone. We use an accurately calibrated torque wrench to periodically check torques.
3. When a bolted hanger is pivoted a few degrees, a thin layer of sandstone is pulverizing behind the hanger bracket, which causes the bolt to loosen significantly -- in some cases to being only finger tight.
4. Within reasonable limits, loose bolts can be retightened to acceptable torque values without adversely affecting the structural integrity of the assembly.
5. New bolted hangers don't always seat perfectly against the rock. After being torqued and re-tightened, they seat better and can better resist being loosened.
6. The new routes in Muir are being climbed extensively. An average of about 175 climbers visit per week. So, some of the routes see more traffic than other places in the Red. More traffic -- more spinners.
As for "constantly tightening bolts", I think this is misleading. Almost all of those bolts found to be loose on new routes, when retightened stay that way.
Of course, if enough victory whips are taken on a bolt, it will have a higher probability of loosening. Funny how on one hand, we love our victory whips knowing that, without question it raises the probability of causing spinners, and on the other hand, we have a disdain for spinners.
Human nature.
Rick
We cannot change the cards we are dealt, just how we play the hand. - Randy Pausch
None are so old as those who have outlived enthusiasm. - Henry David Thoreau