You're supposed to!
I still don't know how richardlerwil (bob_3) got such a perfectly shaped, hand-built, un-"banking" loop, (where alot of tooled loops seem to slightly "bank" at the top of their loops).
It's a matter of skill if hand-building...and, well, skill if tool building [:P]
Firstly, do you have re-roll checked where your loop, loops? Now, make that node 180* and always have it angling...you know how loops are shaped, like that, it's hard to actually explain.
Look at some damn loop pics. dude! Just remember, re-roll, 180*, oh and con-roll at peak. CAN SOMEONE EXPLAIN IT BETTER?