I have climbed last few years mainly on Grivel Rambo 4GrivelRambo 4 on ice falls and Grivel G14GrivelG14 on alpine stuff. Rambo 4 works fine, but it is heavy and due to vertical structure, it doesn't give as good a sensitivity as I would like. This is particularly not ideal on mixed ground and thin ice. Furthermore, it is by far the worst crampon I've ever used to walk on, due to height and point structure. So I think I am going to need to try lighter weight crampons.
I do my drytooling and mixed climbing on fruitboots (older model of La Sportiva Mega IceLa SportivaMega Ice with permanently attached Grivel RacingGrivelRacing crampons). Obviously this combo as far lighter and more sensitive than anything you could realistically expect from any combination of more traditional boot - crampon combo. However, keeping the sensitivity of the fruitboots as a benchmark, my current go-to crampon for ice falls (Grivel Rambo 4) leave a lot to be desired.
Some features I think are important:
- Fit. Good fit consists of multiple things, starting from the general shape. In my case that is a curved frame to fit curved shoes (Scarpa Phantom GuideScarpaPhantom Guide 's in my case). Some other features affecting the fit
- front bail must not be too wide to prevent sideways movement
- back lever must not be too tall so that it does not press ankle painfully (particularly important of softer boots)
- back lever should have a proper retention strap to prevent accidental opening (could be an issue when hooking). Petzl lever has strap on the bottom, which is a very bad design in my book. Both Grivel and BD place the trap to the top of the lever, which make accidental opening of the lever as good as impossible. Luckily, it is possible to fix the issue with Petzl lever by either replacing the lever with BD or Grivel one, or by tinkering with the stock lever.
- Offset monopoint. I have read that some prefer dual points for pure ice. I wholeheartedly disagree. Proponents of dual point usually list more support as benefits for dual points. I don't really buy this arguments. Granted, if you have dual points planted all the way into ice, they would be more supportive than mono point. The problem with this argument is that it is virtually impossible to get dual points planted as well as a mono point. The problem is that when the ice is hard, you usually can't get duals fully in due to added resistance. Duals are also more prone to shatter the ice. Monos on the other hand can be readily placed into your pick holes. Furthermore, monos are far easier to plant on featured ice, not to mention on mixed ground (not a really a contest here). Also, I have found out that duals tend to pop out if you boot twists slightly. This is a common occurrence, at least on my case, when pulling over bulges.
- The point of support is very important though. To boost the support of dual, the secondary points need to placed far enough towards the front. This is a problem with most crampons on sale. Particularly, secondary points of G14 are placed too far back and protrude to little forwards to allow proper support. On Rambo 4 secondary points are better, but they still be placed a bit further forwards. Many models have small teeth facing forward outside the mono. I believe Grivel got this one right with Rambo 4, which has a smaller point about on the position where there would be outside front point on dual points. This is longer than on most crampons for added supports but not too long to cause the same issues as duals do. Pretty much the best of both worlds in my book. I also like the secondary points to angle outside for better hooking and for kicking a ledge to give a welcome rest for calf muscles when placing a screw.
- For hooking performance, points angling out and back are beneficial. This is another part that I really like on Rambo 4.
- Replaceable front point is a benefit, hands down. That being said, secondary points are very important as well. Therefore, I don't see having to replace the whole front part (like is the case with Petzl DartPetzlDart and Grivel G20GrivelG20) as a problem, if spare front parts are actually available and the price isn't too astronomical.
So all in all, Rambo 4 point configuration on flat crampon would be pretty close to my ideal.
Of the crampons available on the market, Petzl Dart, Grivel G20 and upcoming BD StingerBDStinger seem to be the closest thing to those ideals, although none of these are perfects. Biggest issue with the upcoming BD Stinger (based on articles about the test samples) is the configuration of the small points between front point and secondary points. These seem to be located too close to front point and the outer one could be longer. This setup is rumored to change before production crampons hit the shelves, so there's hoping BD will fit the bill pretty closely. Particularly if they have fixed the front bail (far too wide in their previous crampons).