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Matthew Fienup > Santa Barbara Anchor…
With only moderate resistance, the bolt withdrew farther and farther from the hole. Eventually, the bolt withdrew enough that the expansion clip at the bottom of the bolt slipped over the end of the expansion cone and the bolt slid out of the hole.
ID 106071492 · · Copyright Violation?
1/4-inch Star Dryvin (nail & sleeve) bolt removed from Wheeler Gorge. Wheeler is a true sport climbing area with reasonably solid gear that is mostly less than 12 years old--the presence of this bolt came as a bit of a surprise.
The bolt on the right is a 3/8" by 4" Rawl expansion bolt. It is the 2nd lead bolt on "Black's Crack" at Fire Crag. The first bolt on that route (also a 3/8" Rawl) recently pulled out during a lead fall. This was the second lead bolt failure at the crag in recent years. For comparison, on the left is a 1/2" Powers expansion bolt.<br> <br> Bolt failures like the one on "Black's Crack" are actually predictable. Test data compiled by Duane Raleigh and printed in Climbing Magazine in 1992 reveals that these bolts have little holding power in soft rock like that at Fire Crags. In this case, the real-world result is even scarier than the data. The first bolt, which failed, was located 13 feet above the ground. The second bolt is located just 36-inches above the first bolt. The fall that resulted in the failure of the first bolt was therefore of a very low fall factor.
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Matthew Fienup
Nov 29, 2007
“With only moderate resistance, the bolt withdrew farther and farther from the hole. Eventually, the bolt withdrew enough that the expansion clip at the bottom of the bolt slipped over the end of the expansion cone and the bolt slid out of the hole.”  

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Nearby Photos

Here is another view of the 1/4-inch Star Dryvin as it appears in the wall. In the foreground is a 3/8-inch Star Dryvin for comparison. The 3/8-inch variety is very common at nearby climbing areas.
Another view of the (truly) 1/4-inch compression bolt removed from Sespe Gorge.
Here is a view of the two sizes of compression bolts to scale (5/16 on the left; 1/4 on the right) as they appear in the wall. The difference in size is subtle but noticeable.
This detail reveals the significant corrosion of a 25 year old 3/8" stud bolt removed from San Ysidro. Notice that a significant amount of mass has been eliminated from the part of the bolt that actually expands.
Here is the stud bolt that was removed from "Brush Up" alongside a stainless steel Fixe Triplex bolt, like that one that was used for replacement.
5/16-inch by 1.5-inch compression bolt (sold as 8mm x 40mm): one of three anchors removed from atop "the Nose." Brand new, in hard rock, this beauty had between body weight and 4,000-lbs of strength (depending upon how well it was placed). In medium to soft rock (such as ours), this had functionally no strength.
Here is the Fine Line bolt alongside the current offerings from Fixe. The bolt in the middle is a 2.75" wedge bolt (considered totally solid in Sierra granite but sketchy in soft sandstone), while the right-hand bolt is a 3.75" double-wedge.<br> <br> Notice that on the pulled bolt, the expansion clip is gone. Like previous removals, when the bolt was pulled, the expansion clip simply slid over the end of the expansion cone and still resides in the rock.
3/8" "Drop-In" expansion bolt removed from atop Klingon at Gibraltar rock. This bolt has functionally no strength in our soft Central Coast sandstone.<br>
3/8" externally-threaded sleeve bolt--one of two removed from atop the Rapture at Lower Gibraltar. This bolt is actually only 5/16" in diameter (even less on the threaded portion). It has functionally little strength in our soft Central Coast sandstone.
Here is the aforementioned 5/16" compression bolt removed from atop the Nose. It is pictured here alongside a brand new 12mm Fixe Triplex expansion bolt. (A 12mm bolt is only slightly larger than 3/8". The Triplex is actually a 3/8" bolt with a stainless steel sleeve.)<br> <br>
Here is the aforementioned Nail Drive anchor bolt removed from atop T-Crack. It is pictured here alongside a brand new 12mm Fixe Triplex expansion bolt. (A 12mm bolt is only slightly larger than 3/8". The Triplex is actually a 3/8" bolt with a stainless steel sleeve.)<br> <br>
Here is the aforementioned 5/16" lead bolt removed from Face Lift. It is pictured here alongside a brand new 12mm Fixe Triplex expansion bolt. (A 12mm bolt is only slightly larger than 3/8". The Triplex is actually a 3/8" bolt with a stainless steel sleeve.)