In reply to planetmarshall:
> Training to complete a front lever will make you better at front levers. Training for climbing will make you better at climbing.
I almost agree, but not quite and here's why. I've done various front lever exercises for years (well, not much any more at 72...) All kinds of things, front-lever pullups and muscleups, pulling into front levers from full hang, pulling out of front levers, etc. I never could do Gill's one-arm front lever but managed a lot of other stuff. Point being, I know my way around that move.
Over the years, I've had the opportunity to watch many athletes try front levers, and virtually without exception climbers who have never tried a front lever are better at them than any other type of athlete except, of course, gymnasts. If climbers are unusually good at front levers without having worked on them, the front-lever strength must be developed by climbing and so relevant to it.
I do think people get the wrong idea: I don't think front levers have any particular relevance to climbing roofs. What the strength is actually good for is moves on vertical rock that force you to use very low hands and so lever with your arms to keep your body in.
I also don't think front levers should be viewed as a special "core" exercise. Sure, you use you core, as you do for a host of body-weight moves. But you could get the same core involvement by lying on a bench, with your legs from the waist down off the bench, and maintaining a straight horizontal posture.
I think that what front levers mostly train is the triceps and lats; things that give the straight arm levering strength.