Most multi-joint upper-body pulling exercises predominantly train the biceps in the mid to shortened-range position.
To increase your strength, do exercises like preacher curls and what I call "face-away cable curls" shown here.
related posts
Tip: Fix Your Push-Up
Most people can do a lot of push-ups... with terrible form. Here's how to fix that and build upper-body strength.
Brian McFadden July 24
The Deadlift? Who Needs It?
If you're an athlete or a gym rat, how much should you be able to deadlift? Two times your bodyweight? Three times? Or is the better question should you even be deadlifting at all?
Josh Henkin December 16
Tip: Calf Training – The Right Way
Hold the bottom, stretched position for 5 seconds and the top, peak contraction for 3 seconds for optimal calf growth.
Paul Carter January 19
Tip: No-Straps Dumbbell Row
This style of row is great for back hypertrophy and for building your grip for the deadlift. Go for at least 20 reps, Kroc-row style.
Paul Carter August 23