The brake levers should be placed on a straight line emanating from ones shoulder. A common problem is sharp bend at the wrist. Over time it is very likely to cause wrist problems.
The below picture shows properly aligned brake levers: ( the levers should allow the wrist rest in a neutral position, notice no wrist bend )
The below picture illustrates a problematic position for the brake levers. The wrist is bent down too far which will be uncomfortable and creates long term injury risk for the rider. To correct this problem loosen the 5mm bolt to rotate the brake levers up until the riders wrists are straight.
The below picture is another example of improperly aligned brake levers. This time the wrist is bent down too far. To correct, loosen the 5mm bolt to rotate the brake levers down until the riders wrists are straight.
Have any questions? Drop me an email at yanL@downtube.com. Happy riding!