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Gregger Man
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Jan 26, 2015
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Broomfield, CO
· Joined Aug 2004
· Points: 1,769
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Wade J.
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Jan 26, 2015
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Boulder, CO
· Joined Aug 2011
· Points: 25
Route description says the first pitch has a few bolts. Gregger, Thanks for taking the time to replace it. Sounds like a fun climb.
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Gregger Man
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Jan 26, 2015
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Broomfield, CO
· Joined Aug 2004
· Points: 1,769
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Matthew Fienup
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Jan 26, 2015
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Santa Rosa Valley, CA
· Joined Feb 2006
· Points: 7,482
These are usually referred to as "stud bolts" and are not at all uncommon in California. Check out this info, from tests conducted by Duane Raleigh. There are a few more pictures of stud bolts here
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Gregger Man
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Jan 26, 2015
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Broomfield, CO
· Joined Aug 2004
· Points: 1,769
Thanks for the info, Matthew. I haven't run into any of these here in Eldo until now. Looks like a poor design in these dimensions. The Mammut ring bolts work on the same principle but are huge by comparison.
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Greg Barnes
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Jan 26, 2015
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Unknown Hometown
· Joined Apr 2006
· Points: 2,065
Matthew, those aren't stud bolts, stud bolts have expansion sleeves. Of course some people call anything with a threaded head a "stud bolt" but that includes around 10 different types of bolts (not that you can tell from looking at the bolt!). These are a fairly common type of "hardware store bolts", I've seen them now and then all over the place in 1/4" versions (where they are super sketchy). Unfortunately one FA guy in Yosemite Valley & Tuolumne liked the 1/4" versions, thankfully he wasn't too prolific (he also had a bad habit of not leaving hangers on some of his bolts so you'd need a rivet hanger on free climbs). I've found that about two out of three of the 1/4" ones snap off during removal, at least in good granite.
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Jeff G
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Jan 28, 2015
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Colorado
· Joined Feb 2006
· Points: 1,098
Thanks for all the replacement work you do Greg! Sobering to think about what we're clipping a lot of times on these old routes. I did Laughing at the Moon on Monday and all of it's bolts are rusted and look like those in your photo, from the outside anyway.
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20 kN
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Jan 28, 2015
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Unknown Hometown
· Joined Feb 2009
· Points: 1,346
I agree, they are not stud bolts. They are not nail drive bolts either. I forget their name, but basically you have to drill the hole to a specific depth, then you hammer the bolt in and the pin on the back hits the back of the hole, drives into the sleeve, and expands the bolt. They are not suitable for climbing and should be avoided.
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Matthew Fienup
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Feb 5, 2015
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Santa Rosa Valley, CA
· Joined Feb 2006
· Points: 7,482
The type of bolt pictured above is referred to as a "stud bolt" in Duane Raleigh's tests. Per Duane: "How it Works Expansion. Drill the hole to exact depth! Stud bolts expand, creating a friction grip, by the pin being driven up into the bottom of the bolt by hammering." Neither Gregger Man's nor my image has a sleeve in it. Here's a detail of one of these bolts, where the expansion cone (or "pin") enters the body of the bolt:
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Greg Barnes
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Feb 5, 2015
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Unknown Hometown
· Joined Apr 2006
· Points: 2,065
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Matthew Fienup
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Feb 5, 2015
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Santa Rosa Valley, CA
· Joined Feb 2006
· Points: 7,482
Cool, Greg. Thanks for clarifying. Duane refers to the stud bolt that you link to as a "wedge bolt."
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