I'm in the process of building up a 2008 Cervelo P3C and I'm struggling to get a good bend to the derailleur cables from my aero bars to the downtube stops.

The downtube drilled stop is about a 45 degree angle so the cable has to make a severe bend at that point. I've seen photos of built P3Cs and they seem to be able to make the bend.

Is there a way to pre bend the housing?