I thought building a bike would be much easier but I'm getting more and more lost. The drivetrain is what's confusing me so much. So I contacted titus (Ihave a titus motolite) about bottom bracket dimensions and they said the BB I buy should be 73mm and that spindle length doesn't matter. But then I was reading that you need a certain length spindle to have a proper chainline. Can anyone clarify...can I just use whatever spindle length I want?