I finally got my new bike and am looking forward to start putting many miles on it, the only problem is that the bike is the weakest part of triathlon for me. I just have a really difficult time getting comfortable and find that it take a lot more effort for me to ride than to run or swim. Everytime I get on my bike my quads just burn, and I'm in no way weak or out of shape. Is it my positioning or just the fact that I'm not used to being on my bike? Thanks for advice/suggestions!