Converting a Di2 only frame to mechanical
 

I have a Focus Cayo Evo road bike that is Di2 only, and a Redline Conquest Team CX bike that can take electronic and mechanical but currently has SRAM Rival. I want to switch drivetrains between the two bikes.

Since the internal routing on the Focus is completely incompatible with mechanical cables and housing, I'd have to do full length housing. I know it's ugly, but I don't care. For the rear derailleur, I'd run it along the downtube and secure it at the chainstay, where there are two bolts on the bottom to hold the Di2 battery. For the front, I'd do the same thing, except I'd use a separate cable stop that clamps on to the seattube.

I have a few questions. For the chainstay guide, I'd need something like this: Ragley Triple Cable Guide Kit | Chain Reaction Cycles . Does anybody know where to find these? And does anybody know where I could find a clamp on front derailleur cable stop?

For both the front and rear housings, I still need a way to secure the housings near the junction of the downtube and the headtube. Does anybody have suggestions for this, preferably something that won't scratch the carbon? The downtube is huge and not round, so I can't use traditional clamp on stops.

And finally, if you think my entire plan is flawed and bogus, do you have any better ideas how to do this? No carbon drilling suggestions please, I don't want to take that risk. Thanks!

Since you are going to run full-length housing you just need a support, not a stop. You might try strapping the housing to the frame with self-fusing silicone tape. It only sticks to itself so it doesn't bleed adhesive and comes off clean. Comes in many colors including clear.

Can't you just get a Mechanical Cable Routing Plate from a Focus dealer to convert your frame to mechanical? Or is the Evo completely different from the rest of the Cayo frames?

Focus - Bikes: Cable Plug

Nope, I have the previous generation Cayo which doesn't have the cable routing plate. Looks like for now silicone tape is the best option.

there are self adhesive tie patches that you then can use a zip tie around cable housing Or hydraulic hoses