First of all I am not a curl bro and yes I do work my legs. Only reason I say this is because threads about biceps seem to get flamed sometimes.
My question is whenever I do bicep exercises: dumbbell curl, hammer curl, barbell curl, pretty much any type of curl, my front delts always fatigue before my biceps do and I feel like my biceps don't get adequate work from this.
I keep my shoulder blades retracted, elbows remain in the same position, and have experimented with heavy and light weights but nothing seems to help. The only exercises I can really feel my biceps working in are incline dumbbell curls and sometimes on concentration preacher curls.
Is this just a case of having weak shoulders or is it something else? I was thinking if I incorporate more rear delt work it will help stabilize my front delt because I haven't been doing much direct rear delt work lately.
Any opinions are welcome