One of the most common things I see wrong on most drop bar set ups for off roading, (besides seeing the bars too low) are brake levers set too high on the curve of the drop section.
<=== Notice how low on the bend of the Gary Bar's drop I have this old Shimano SLR aero lever set. The clamp is set just above the center of the drops curve which puts the end of the lever far below the drops extension when that extension is parallel to the ground. The thing is though, you normally tilt the extension so that the extensions point downwards toward the rear axle. In this position, the lever tip should be even on an imaginary line drawn from the lever tip to the tip of the extension parallel to the ground.
<=== With the lever in this position on the bar, when you are riding in the primary position (In the drop) your hand will be in close proximity to the lever for ease of braking in an off road situation. I will also add that I probably should have had another person take the picture! I had to do quite the contortion to get these shots!
<==== Okay, back to the matter at hand! Speaking of "hand", the one in your off road drop set up should be capable of reaching out with the index finger and wrapping the end of that finger around the tip of the lever. From there you can pull it back and wrap a second finger around the lever if you choose to. However; I find that I normally do not need to do that as the leverage is high enough that I can generate enough power with one finger to do all but the most demanding sort of braking you might require off road. You wouldn't be able to do this from the drops if your levers are set too high. One tip: It is a wise thing to leave the tape off your newly set up drop bar bike and go for a casual ride around the block to determine whhether or not your lever position is correct from the drop. If it isn't, a quick wrench weilding session is all it takes to adjust it, and you don't have to wrap and re-wrap your bars.
<=== So....maybe you were wondering how I get SLR aero levers to work with BB-7 mountain disc brakes? Well, take a look here. I have the lever pulled much, much further back than one could on a traditional road bike drop bar. This allows me to pull more cable, which is just what the mountain BB-7 requires. (And I don't even have the lever pulled back all the way to the bar in this picture.) Having the lever higher up on the drop would prevent me from doing this, by the way.
True, this set up is definitely not recommended. It is not supposed to work. Be that as it may, this will be the third time I have used this combination, so ...........here I am, still alive to write about it!
Here's another look at the set up from the front of the bike. Notice how much "slope" the Gary Bar has which makes the tops a bit narrower than the otherwise similar Midge Bar from On One.
The benefit of having those "sloping" drops is that it opens up a place for your arms and wrists to move around, especially laterally. This is most handy while rocking the bike side to side up a steep climb. Also notice the shallow drop which makes finding a workable stem a bit easier.
Okay, next up will be a final look at my drop bar set up on this Karate Monkey, and a "wrap up" on all of this drop bar madness for off roading.