We've run into a cabling challenge while building a new road bike. I am familiar with installing Shimano STI levers using downtube mounted cable adjusters. However, this frame does not accomodate the option of using downtune shifters. It only has bosses on the headtube for the derailleur cables.

The challenge is, once the cables are run to the derailleurs, they are in the direct path of the front Caliper Brake cable. Therefore, if I turn the front wheel, the front brake cable hits the derailleur cables.

I know plenty of the newer frames don't accomodate downtube shifters and use the bosses on the headtube. How do you overcome this cabling challenge? See Illustration.

Thanks in advance