Internal cable routing - achieving balance

[svanimpe]

I'm building up my first bike with cables routed through the headset and stem/handlebar. My setup is as follows:

- This is 105 Di2, so only brake hoses, no shift or Di2 cables.
- Front brake hose is routed through the fork, and taped to the fork where it exits, then goes up through the headset and spacers (always keeping left), going through the left shifter.
- Rear brake hose is routed through the frame, then goes up through the headset and spacers (always keeping right), going through the right shifter.

My problem is that with this setup, my handlebars always pull right, rather strongly, so I plan to redo my setup, to figure out what's causing the handlebars to pull right.

Any tips on how to achieve proper balance?

[s3si1u]

Rear brake hose might be too short

[BerndSon]

My problem is that with this setup, my handlebars always pull right, rather strongly, so I plan to redo my setup, to figure out what's causing the handlebars to pull right.

Any tips on how to achieve proper balance?

hi there,

faced the same issue with my ultegra di2 12s. First thought its due to a "wrong" routing of one of the two cables or a short rear brake hose which caused the handlebar to move to one side like there would be a spring inside

After Ensuring its was none of the above mentioned causes it turned out was just about the natural bends and tension in the brake hoses.

I fixed it with try and error in the following way:   grab one cable after another with with pliers and the special jaws to grip the cable firmly without damaging it. Twist the cable 1-2 times around its own axis and see if anything has changed for the better or worse.  If necessary, change the direction or continue with the second cable. It works best when the handlebar is dismounted and the cables are coming out from the Stem because you can then better grasp the cables, but has also worked with mounted handlebars.

please report about your experience after trial.
Good luck.

[svanimpe]

I'm not sure that was the issue, but I had taped the front brake hose to the fork (as you always see people doing). On my second attempt, I removed that tape and just let the cable hang free, and now the issue seems to be resolved.