RRC Archives

New Glue-in Bolt

Today, we tested the new Jim Titt-designed “Buehler-typeâ€

Sounds great!

The other concern would be getting climbers to actually trust something that looks so different than a typical hanger, even if it is safer and makes more sense...

Thanks again for doing this extensive testing!

The results run counter to my 'gut feeling' - I would expect a 'fat bolt' with a nice thick punched-out-of-plate bolt to be stronger than 'a pice of wire'. It's the ability of the continuous strand of 'wire' to deform and stretch that allows it to withstand more force. There are no welds to fail, and no 'right angle' connection between hanger and bolt head to shear off. Nonetheless, I always feel a bit less secure than clipping the familiar hanger!

By the way, have you determined what the realistic maximum force on a 'bolt' can be expected to be generated by a falling climber? (I'm wondering wether that initial cracking under a 1 kip load could mean that hard falls would result in 'scary' looking (but safe) damage around the bolt?)

One piece solid stainless is really nice.

That bolt looks crazy. How long is it?

tomdarch wrote:
The results run counter to my 'gut feeling' - I would expect a 'fat bolt' with a nice thick punched-out-of-plate bolt to be stronger than 'a pice of wire'. It's the ability of the continuous strand of 'wire' to deform and stretch that allows it to withstand more force. There are no welds to fail, and no 'right angle' connection between hanger and bolt head to shear off. Nonetheless, I always feel a bit less secure than clipping the familiar hanger!

Me too! It took a while to warm up to this thing. Most people's first impression will probably be, "WTF???"

tomdarch wrote:By the way, have you determined what the realistic maximum force on a 'bolt' can be expected to be generated by a falling climber? (I'm wondering wether that initial cracking under a 1 kip load could mean that hard falls would result in 'scary' looking (but safe) damage around the bolt?)

I'll try to located the tests that were done recently with a load cell on a falling climber to determine the maximum safe load he can take before bodily injuries start occuring. I think it was about 800 pounds on the harness. I would guess that repeated big whips in this range could distort this bolt over time, but how much? We can easily test this, once we determine the max. falling force.

Our load cell can be attached to a falling climber to see what a typical big whip of say 30 feet would generate, but of course we don't want to test to the point of injury.

We have some more prototypes on the way here that are made from 8 mm s.s. rod instead of the 6 mm of the ones in my post. Problem is, they cost quite a bit more and require a 15mm-dia. hole with a lot more epoxy. Their strength will be way off the scale on the high side.

The Chinese insatiable demand for steel is driving the price of steel and stainless steel through the roof. All fasteners -- mechanical, glue-in, etc. are going up in price.

Rick

Andrew wrote:That bolt looks crazy. How long is it?

How long do you want it to be?

The nature of the design allows for any length -- just twist it a bit more. The standard lengths are 100 and 150 mm. I prefer the 150 mm (about 5 inches) as this is the same length as the Fixe glue-ins. Both the Titt and Fixe glue-ins test very well at this length.

Rick

Look great!

Question, Can you safely thread a rope through that bolt/hanger? If not, do you think people might to tempted to more so than a regular hanger?

I love science.

Some concerns:

1 Some of the biners on the bolt end of my draws have groves worn in them forming sharp edges. I wonder if these edges might cause a problem?

2 Sometimes the sandstone contain larger agrigate (stones) sharp edges. What happens when one of these sharp edges is trapped under the bending bolt/wire?

3 One fall to the right a few degrees. One fall to the left a few degrees. One fall straight down. Saw?

cool!

how does a developer bolt anything overhanging with glue-ins in an efficient manner?