Seat Tube Confusion
I'm embarking on designing my first frame and ordering the tubes and such and I'm having a hard time understanding when/if a seat tube collar is needed. I'm trying to find the right seat tube to buy and just a bit confused. I'm building a SS Mtb and the BikeCad model I'm going off of has a bent ST which has been hard to find. I found one on frame builder supply but it's external butted which I don't know if I need a seat tube collar with it. I'm diving straight in but need to learn a lot!