Having installed countless internally routed brake lines both personally and professionally, not too many frames have given me trouble. Lack of internal guides is getting rarer and rarer these days but the ones that don't have the guides usually come from the factory with a plastic hose installed, run your guide cable through that, pull the hose through, done.
If the frame has brakes in it already, just cut the line, thread the guide cable's barb into that, and pull it through. Then you have the guide cable ready to pull through the new brake line. Jagwire foam tubing is a pretty easy install for noise dampening, just slide on from the down tube door. I also have used self adhesive neoprene foam cut into a thin strip and wrapped around the brake hose like a candy cane stripe. Stuff can be found cheap at any hardware store.
Once the brake is in the frame, I appreciate the clean look. I don't have to worry about zip ties braking, or mud clinging to an external line and sanding away at the paint underneath. It's just cleaner and more protected inside there than external.
The one exception I've found was a recent model Stumpjumper Alloy where the internal cable has to make such an abrupt turn from the downtube port under the BB and back up into the rear triangle that the guide barb just won't fit. You basically have to partially disassemble the suspension to get it in there and you still have to fish it through the chainstay.
Other than that, I don't really get all the complaints. Tube in tube internal routing is easier than external cable guides and you have to trim new brake lines anyway. Internal without guides maybe adds 5-10 minutes of extra work to a brake install and in my opinion, the benefits are worth it.
June 28, 2022, 11:44 a.m. - rusty904
Having installed countless internally routed brake lines both personally and professionally, not too many frames have given me trouble. Lack of internal guides is getting rarer and rarer these days but the ones that don't have the guides usually come from the factory with a plastic hose installed, run your guide cable through that, pull the hose through, done. If the frame has brakes in it already, just cut the line, thread the guide cable's barb into that, and pull it through. Then you have the guide cable ready to pull through the new brake line. Jagwire foam tubing is a pretty easy install for noise dampening, just slide on from the down tube door. I also have used self adhesive neoprene foam cut into a thin strip and wrapped around the brake hose like a candy cane stripe. Stuff can be found cheap at any hardware store. Once the brake is in the frame, I appreciate the clean look. I don't have to worry about zip ties braking, or mud clinging to an external line and sanding away at the paint underneath. It's just cleaner and more protected inside there than external. The one exception I've found was a recent model Stumpjumper Alloy where the internal cable has to make such an abrupt turn from the downtube port under the BB and back up into the rear triangle that the guide barb just won't fit. You basically have to partially disassemble the suspension to get it in there and you still have to fish it through the chainstay. Other than that, I don't really get all the complaints. Tube in tube internal routing is easier than external cable guides and you have to trim new brake lines anyway. Internal without guides maybe adds 5-10 minutes of extra work to a brake install and in my opinion, the benefits are worth it.