Crampon Rebuild Advice???

[blacklab2020]

Recently I had one of my crampons fall apart on me... Very luckily it was on the trail and not on a pitch of vertical ice.

Has any one had experience with this before? I will be reconstructing it in the next day or so, most definitely using loc-tite on the bolts/nut.

I had just cleaned the crampons (grivel rambo I) and replaced the frontpoints. I had just switched boots to La Sportiva Trangos for the first use.. The soles are rigid, but the top tends to be more flexible. I had only gone a couple of miles before the one came apart.

Just looking for suggestions other than loc-tite, etc for the re-build.

 

[Paradox]

Assemble the bolt, washer, and nut. Then take a steel center punch and drive it hard into the center of the bolt along its axis with a hammer flaring the end of the bolt. That holds the bolt on.

 

[Kevin Rooney]

Recently I had one of my crampons fall apart on me...

Am not quite sure what "fall apart" means. You mentioned loctite, so if it's just a bolt that one's thing, but if one of them broke ... quite another. Might signal metal fatigue (often not visible to the naked eye) so replacement might be in order. Grivel has a table on their website for suggested replacement cycles.

If it's just nuts that won't stay on and loctite won't do, try Paradox suggestion, or simply bung up the threads.

(Different topic - we all know what 'naked eye' means, but what's the opposite of that? Might be a question for George Carlin.)

 

[Lou Hale]

If it's just nuts that won't stay on and loctite won't do, try Paradox suggestion, or simply bung up the threads.

they make a locking nut with pre bunged threads available at most hardware stores look for a square dimple on the side of the side of the nut

 

[blacklab2020]

three nuts eventually fell off on the trail... one at a time... and i heard a clinking... and then the side part of the crampon came undone, they used locking nuts with these crampons, could repeated taking them apart and putting back together wear them down?

 

[DougPaul]

three nuts eventually fell off on the trail... one at a time... and i heard a clinking... and then the side part of the crampon came undone, they used locking nuts with these crampons, could repeated taking them apart and putting back together wear them down?

More likely, taking them apart and reassembling them cleaned off the rust and dirt that had been locking the nuts in place. Hopefully, you had tightened them sufficiently before you went out...

One caution about Paradox's procedure--if you spread the screw ends too much, you may not be able to take them apart again. (Or you may have to shear the screws off and reassemble with new hardware.)

Doug

 

[spider solo]

just curious

While I couldn't find a picture of the Grivel Rambo 1 it got me to thinking when I read about replacing the front points, taking the sides apart, and things like that.
I did find the Rambo 4 version and saw all the screws etc and realized these are primarily for vertical stuff.

Figured you were on an approach trail when they failed.?

I have the La Trango Sportiva boots that I sometimes use as a winter boot..with those I use my most flexible crampons.
So it occured to me (if I'm comparing apples for apples) that if you do cinch the screws down nice and tight and locked on that the crampons might fail or break because they are trying to flex with your boot to much.

In other word the scews themselves were taking the abuse and solved the "problem" by unthreading...figure you could tell if they were literally sheared off, (but perhaps they were lost when they fell apart) .

Perhaps that is already your thinking as you gave reference to the boot you were wearing but thought I would mention it just in case....

 

[Lawn Sale]

There are 2 main types of locking nuts, one where the nut is all metal and is deformed slightly, so it looks a little oblonged. The other is a nylock nut, where the end of it has some plastic, which deforms and locks to the bolt when in place. Repeated removing of these nuts will wear out, or cut threads, into the plastic portion, making the nut no longer self-locking. The nylock nuts are advertized as a one time use, but I have found they can be removed a few times before they have to be replaced. My Petzl M-10's have nylock nuts, but I have replaced the front points and sharpened/cleaned them and the nuts still grip fine.

There is nothing wrong with going to the oblonged type locking nut, I prefer them but they are harder to find in the smaller sizes.

 

[blacklab2020]

spider solo.... I just looked at the threads this morning, and they are really sheared...this could be possible. I have heard of more flexible crampons breaking with soft sole boots...

The other thing that occured was the juncture of the frontpoints and bolts is slightly wider for these front points, reducing the available thread for the nut to lock onto...With the slightly wider width, they could have also taking the force while adjusting.

Its possible that these were overtightened. I am taking the rest of this up with grivel (I cant reuse these bolts and havent really found any that compare) and will likely pass the front points on and get a new pair of crampons.

Thanks to all for the input.