i just always wear tri shorts on the bike.........less is better a lot of us discovered.......only one layer and minor padding means less chance of chaffing............
if you are planning on wearing bike shorts then don't wear them in the swim as the excess padding will get soaked............just strip naked in transistion and put them on dry and freah............the same when you change in t2 to running shorts........
if you are planning on getting changed in trainsition./.... then you have to train harder to give youeself more time..............i take of the wetsuit and put on socks and bike stuff and then get going..............
the faster you are the more time you have in transition to dry your hair and change........the slower you are then you need to be looking to save any spare minutes you can