I'm really enjoying cycling (training for 100km next spring) and can hold my own on a shortish run and would love to do a triathlon next summer but am a seriously bad swimmer 
Is swimming for a triathlon something that can be learned & with training manage ok or should I be looking for a duathlon & give up triathlon dreams?
As an aside, how much time commitment is needed for a sprint triathlon? I'm cycling 2-3 times a week plus doing either a run or cardio class at the moment and not sure how much more I can fit in.