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I am in the process of building a Moonboard or basically a home climbing wall which is used for bouldering training. However, because I am not a fan of overhangs, I have built it vertically (the building instructions specify it to be a 40° overhang).

Now, online there are many problems for the Moonboard which have graded from V5 up to V14. However, these are all problems which have been set on an overhanging wall, so how can I find out what grade these problems would be on a vertical wall?

  • 3
    Possible duplicate of How does a route setter grade a climb? – user2766 Sep 12 '16 at 16:26
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    Basically, you can't really do this, there is no hard or fast rules on when or if x overhang increases the grade y amount. It's all based on experience and comparision to other climbs. – user2766 Sep 12 '16 at 16:27
  • Hi Beta Decay. Have you checked out the question Liam thought might be a duplicate? Did it answer this question, in addition to the answer you already have here? I don't want to add a duplicate vote if this is substantially different and should stand on its own. Thanks! – Sue Saddest Farewell TGO GL Sep 13 '16 at 18:47
  • @Sue I wouldn't say it's a duplicate per se, but it's too close to call. So I would say it is a dupe – Beta Decay Sep 13 '16 at 19:03
  • Ok. Thanks so much. I already upvoted, and will add a dupe vote, though that doesn't mean the rest of the community agrees. I just didn't want to slam shut your question! – Sue Saddest Farewell TGO GL Sep 13 '16 at 19:09
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Contrary to e.g. the aid climbing difficulty scale, sports climbing and bouldering scales are comparative (at least in the grades that came up after the seventies). So a grade does not directly tell how hard a climb is, it just says how hard it is related to others. You can see this very well by sometimes drastically different hard routes with the same grade in different crags or gyms. There are two gyms within 10 driving minutes of each other, where equally hard routes have like two French grades difference. What I want to say with this: There is no definite way and you should not concentrate too much on grades.

Therefore the only way to transform the grades is by finding a "normal" overhanging moonboard and compare it. I will give some ideas of what makes it harder with an overhang, but these factors cannot be quantified as in 10deg is half a grade.

In terms of holds it is pretty easy to see (isolating it from other factors): Big jugs and slopers are not much different, crimps are. The difficulty of holding a crimp is more or less given by its size and "positivity" (angle of contact area against direction of gravity). This obviously directly changes with the angle of the overhanging wall. One might even come up with some quantification in terms of grades for this.

Then there is weight support by legs. Ideally in climbing you support all your weight with the legs and the hands/arms are only for keeping you at the wall. Of course this is no longer the case for harder routes, but it still holds that you should support as much weight as possible with your legs. In an overhang you have to lean back, so even with perfect foot placement (kneebars excluded) you will have to hold significantly much more weight with your hands. This is actually just trigonometry, so an estimate of how much more force could be made and translated to a grade, but again thats useless (see above).

The third thing I come up with right now is body positioning. In an overhang you need to kind of fixate yourself with opposite arms and legs between two holds. This needs a whole lot of body tension. In addition it is a very different way to hold and stand on a hold than when you are climbing a vertical face. The direction of pull/push, the way you grab it may be completely different. So a routesetter will always have this in mind: If a route is overhanging he will do it completely different than on a face. Therefore your routes will be suboptimal as they were designed for an overhang and you will use them vertically. This can mean they are disproportionally easy, but it could also mean that it is just as hard as in a overhang.

I suggest you either mount it as it was designed for, or you set your own routes for vertical walls. Setting routes is very difficult at first, but you learn a lot as you have to think about movements in advance, which is an advanced skill, but a very useful one.

  • Would love to give you +2 for this, great answer. Relating crimps and their positivity, you mean if you just use friction while hanging on the crimp I guess. If you clamp/squeeze the crimp or ledge it's not directly linked to the degree of overhang angle in my opinion. Of course you still need to move differently and have a lot more weight to pull up/hold while climbing. – Wills Sep 12 '16 at 22:07
  • @Wills Yes this mainly applies to "friction" crimps, but subjectively this is the majority of crimps. And even if you can clamp it is much harder to do if the contact areas are sloped towards each other than when they are "edged inward". I am sorry I am totally at a loss to express what I mean understandably but succinct in English. – imsodin Sep 13 '16 at 5:17

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