/ G12 new classic crampons too flexible
That shouldn't be the case. You should be able to use flexible crampons on stiff boots, just not the other way round. I regularly wear G12s with B3 boots.
You got a black bar or the silver one? I think these come with stiff black or flexible silver bars, and you can choose which suit your boots. If you have a silver one, swapping to the black one might help.
That said, this is the first I've heard of a crampon coming off because it's more flexible than the boot. The other way round, yes, but this is new to me. Are you sure they are adjusted right?
Edit: Your profile indicates you're no winter newbie, so I daresay you know how to adjust a pair of crampons. I'll still be a bit surprised if the flexibility is the problem though. What boots are you using with them?
Climbed 4 days previously no problem,just that one route both came off(hard ice)v.
When you say 'came undone' what do you mean? G12s have a variety of attachment systems - which are you talking about? Straps loosened?
Its rare that 'over-flexibility' is an issue if crampons are effectively fitted and secured.
He does say new classic, which is the version with plastic baskets front and back, joined by a single strap. So no bails or clips as such. I must confess we've used the similar monta rosa on everything from stiff trainer to B3s without issues, so I'm surprised they came off. Presumably the straps came loose?
As I say, it shouldn't occur. It shouldn't matter how flexible crampons are as they are fixed to something solid (the boot).
Sounds like my worst nightmare, glad you survived! I use G12's on B3's and I'd need a crowbar to get them off although they have to be pretty tight to my boot or they slip a bit (new classic binding so impossible to actually "come off" without a pair of scissors). Grivel make the G12's with the crampomatic binding which will only work on B3's so there shouldn't be an issue flexibility wise, they're designed to go on B3's. Maybe just an unlucky combination with your boots, what boots are you using?
Strap-on G12s? I didn't realise you could still buy them. They're what I'm currently using (until the points wear down).
Oops, didn't see that. I'm stumped then, no idea how that could have happened.
I climbed with an experienced guide,we checked them afterwards the bar was definately flexing,this is why I'm considering bolting them,used to have g14's then lightened to these.
La sportiva baturas
If there's definitely something wrong with the crampons then take them back to the shop. If you modify them and they're no better afterwards, you won't be covered.
Assuming you have the standard (black powder-coated chromaloy) bars, not the spring (silver uncoated steel) bars, they really should not bend much. Any flexing should happen where the bar joins the frames, mostly the front frame. Though with an accordion fitted, I guess it might be hard to tell the difference.
Do you have unreasonably large feet? that can make bending worse.
I guess when front pointing, the points lift up, and the crampon bends down away from the boot. It probably won't come off, the new classic binding is almost impossible to get right off when done up correctly. But if it becomes loose enough for the toe of the boot to ride up over the posts, it'll still spoil your day. Adjusting the crampon so that the posts are hard up against the boot front and back could help, though getting a perfect fit is impossible if you're half way between settings. The new-matic binding (with a heel clip) might help too, as it pushes the boot forward hard against the front posts. As might super asymmetrical bars, if your boots are quite curved - because you'll go from three to four posts in contact.
If you do decide to try and stiffen them up, you need to be sure whether it is the bar bending or the joints between bar and frame. Not much you can do about the former, other than custom bars. If the latter, then bolting the bar to the frame will do the trick, but there's not a lot of metal to be drilling holes in. A clamp holding the two together might be better than bolts.
Or, of course, go back to G14s for ice. Strap-on G12s aren't really in their element on grade V ice. That's not to say they are unsuitable, but being nearer their limit any incompatibility with the boot is going to be more noticed.
In reply to cookieman:
BTW it's my video but since I highlighted the problem, Grivel have completely redone the spring-clip and it's much much safer though haven't actually said anything about it!
Having said that the G14 and G12 use exactly the same system and half of my clients with their own crampons, have the accordion wrongly positioned.
IMHO, if it's been a problem it's either a user/fitting error or a problem with the crampons.
I never use the accordion and mine don't come undone so I'd likely expect user error and not reading the instructions!
I'm surprised no one has asked yet, what shoe size are you? I could be wrong, but I thought it was well known that if you have large feet then the crampon is more flexible making it more like a C1, especially if you have the plastic baskets back and front.
No problem with the G14's but with the G12's indicates something else as apart from the front points they are exactly identical!
They are rather large at 46
Your boot size makes no difference as the G14 and G12's with the same binding system are exactly the same...
Exactly the same never had issues with the g14 nearly 10 years use
So you are saying the 'new' G12 and G14 crampons have an issue since the adjustment bar springclip has been changed?
The g14 attachment clip seems more solid,grivels website says the clip can be replaced with a screw and bolt,this is what I was looking for.Still think shouldn't happen to modern crampns,as it was a Smith and Marshall route I wondered what their ascent must of been like,then I was engulfed in spindrift,3 parties on tower ridge seemed amused by what was going on the opposite buttress,thanks again for comments
I've now got f'all do with Grivel but the G12 and G14 binding are exactly the same so any problems will be the same, I like to help folk, just don't waste my time.
Replacing with the screw and bolt will be more secure as long as you don't mind losing the easy adjustment option of the spring-clips.
If there is a genuine safety issue with the latest models, I'm happy to highlight it...
Perhaps cookieman had a different binding system on his G14s, and that's why they were fine on those boots?
His G12s are new classic.
His G14s were presumably new-matic or cramp-o-matic, as G14 new classic doesn't exist.
The new-matic and cramp-o-matic bindings have a heel clip, which pushes the boot forwards in the crampon. It also pulls the crampon tight across the bottom of the boot, which will tend to reduce bending, and reduce the risk of it coming off.
Didn't mean to waste your time,looking for advice was my objective,I had a mini epic and hope to avoid it again,it's why I posted
How old are your G12 new classic crampons? I have a pair of G12 newmatics which are about 8 years old now. They have been fine until this winter when the right one has fallen off in use. First time in the IceFactor so didn't matter. Then Tuesday this week on a route on Brown Cove Crag. On close inspection the spring on the right crampon is noticeably weaker than on the left crampon.
After searching online Needle Sports sell Grivel spares including springs and also bolts for bolting the crampon together which they say is best anyway. They also say make sure the accordian is over the spring or the crampon can come apart.I have ordered parts this evening as it happens.
Actually not the same springs, g14 much stronger,should of used long bars instead of standard ones,completely my fault taking these things for granted will order new clips from needle sports and change to long bars
I have old G12s; the original adjustment spring clip was a crappy design and after some medium use it lost its "springy-ness" and would no longer sit securely down in the holes. They never fell apart but looked like they might. I took the spring clips off, threw them away, and put bolts in instead. I do actually change them between different boots quite regularly so needing to unbolt them to change size is a hassle, you just need to make sure you have the right size tools handy.
I have G12s on very large boots (size 50) with no problems except one. When walking in snow with a breakable crust occasionally the crust slowly loosens the strap buckle, which can lead to the strap and then crampon coming undone. Ensuring the buckle is more on top of the boot than to one side largely solves this.
when you do your strap up do you twist the black tab 180 so it faces your heal? This can help prevent the straps loosening.
Yes. I doesn't happen very often but the crust can catch the buckle and slowly loosen it. Memorably this resulted in a crampon coming off on a glacier once and me not noticing for several hundred metres and having to walk back to find it!
I guess its possible the black tab got twisted back around and this then helped loosen the straps.
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