I will be doing my first "long" tri at the Ohio 70.3 in August. I have done a few sprints and one Olympic (in 2012), but only marathons in the recent past (I am currently training for Boston). I need some help with my weakest link which is the bike (I was a swimmer in HS and College). The trainer just kills me as I can last about 20 min - can anyone recommend someone/something - coach, class, camp, etc. - that might help me improve in this area? I'm not afraid of the distance as I have ridden that far before, but I'd like to improve nonetheless. Thanks.