I don't want to sound like an anti-gym arsehole, since I've spent as much time indoors as on the rock (and enjoyed it, too) but I don't think the Ewbank system really works for gyms. If you must grade climbs (as opposed to just saying "I can do it," or "I can't do it"), then just use "Easy," "Moderate," "Hard," "Nails," "Dai." Or something like that.
If you insist on using Ewbank grades, then you can't really bitch about how gyms don't compare. Why not? Well, crags don't really compare either - I know plenty of people who could walk up a 26 at Nowra or the Blueys, but would get absolutely wankered over a 26 at Booroomba or Orroral. |