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U.S. Built Custom Bicycles in Titanium and Titanium-Carbon Mix

Internal Routing Set Up & Maintenance

IMPORTANT: This page and instructions are intended for professional bike mechanics. If you don't work with internally routed bikes as part of your daily job, do not set up your Seven internal routing. Internally routed bikes require different skills than externally routed bikes. Installing the routing improperly can cause fork failure or brake failure that results in danger while riding, serious injury, or death. If you are not a professional bike mechanic, do not set up Seven internal routing.

To see an overview of Seven's cable routing options, visit our routing page.

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internal routing head tube single ht gravel carbon
Head tube port for internal rear brake housing. On an Evergreen PRO.

Overview

All internal cable routing systems for any bike from any builder have their own set of benefits and considerations. No system is perfect. That's part of what you pay for when you buy an internally routed bike. One of the primary challenges with most systems is the initial setup. While Seven's system has a couple of unusual challenges, they're no bigger than any other system we know of. And the benefits of our system far outweigh the setup time.

Seven's internal system is not intuitive, so make sure you follow these instructions carefully. If you don't, we make no promises about how well it will or won't work for you.

Taking the time to initially set up the system properly is both important and worthwhile. We believe our system is better, more durable, and more functional than just about any other system out there.

How is Seven's internal routing unusual?

From a mechanic's standpoint:

Fork steerer friction: The head tube internal housing will brush the fork steerer. This creates nominal friction on the freedom of fork turning. You will notice this, but it will not impact steering performance. This interference fit is required in order for the internal system to work properly. Depending on the fork model and the requested internal routing design, the friction level will vary. Some forks have minimal drag, and some are more noticeable. While this is unusual, it allows Seven to provide the most durable and aero internal system available. The tradeoff is well worth it.

For a full list of the considerations for Seven's internal routing system, visit the "Considerations" section of our routing page.

Benefits of Seven's Unique Internal Routing Design

We think Seven's internal routing is the best in the industry. Here are some of the reasons.

  • No special parts or proprietary components: While our design is progressive and unique, you don't need any special pieces to make it work = futureproofing. Our system doesn't require special headsets or stems that will be obsolete in three years = futureproofing. You just need your pro-level mechanic tool kit.
  • Tailored approach: The number and size of ports are to the rider's preference. Some bikes need one port. Some bikes need four ports. We don't do what most builders do — either have big holes that are a catchall for any possible cable routing stuff or multiple holes with sad rubber plugs to block the holes you don't need. We give you what and nothing you don't. It's cleaner, has fewer issues to manage, less stuff to lose, fewer holes for fewer problems, fewer contaminants in the frame, and fewer durability issues.
  • Lots of models: Our system works with just about any category of bike: Road, gravel, mountain, plus, and fat. The primary exclusion is that we cannot offer internal routing on our tandems.
  • The most durable: By avoiding punching holes in the high-stress areas of the frame, we're able to include this system in our frame's lifetime warranty.
  • Clean lines and a contemporary look: No other builder is offering — yet — internal routing that enters at the head tube. It is truer functional internal routing that doesn't require special proprietary parts than any other metal bike we know. We think it's cleaner. And it's more aerodynamic for those chasing watts.

Recommended Tools & Supplies For Set Up

In addition to the standard mechanic tools you'd use for any pro-level brake, shifter, and internal routing build, you'll also need:

  • Gorilla Tape™ or equivalent of durable and very sticky tape.
  • Frame protectors; the clear kind you'd use on any carbon frame.
  • Heat shrink sheathing, tubing, or hose made of polyolefin: We recommend 3M™'s product, but there are other options available. Have two sizes available depending on the customer's setup. We prefer:
    • 1/4" diameter or 6.4 mm: Ideal for single housing or single housing with a Di2 or EPS wire.
    • 3/8" diameter or 9.5 mm: Ideal for two housings together.
  • Heat gun that reaches a minimum of 100c or 212f.
  • Silver/white paint pen or Sharpie™

Set Up Instructions

There are dozens of great videos and articles about how to set up and optimize internal cable routing. We're not going to go through the basics of internal routing setup. These instructions are only for the specific nuances of Seven's internal routing system.

General housing set up information:

  • Lace the housing through the frame from its rearmost ports.
  • Bottom bracket shell lacing: Use whatever bottom bracket sleeve comes with the T47 cartridge system. This is important to eliminate the possibility of spindle wear on the brake/shifter housing. The fit of the sleeve and housing will be tight. Think of this as a good situation because it will help minimize housing rattle.
  • Apply heat-shrink sheathing to entry and exit ports. Reason: The sheathing increases the brake and shifter housing's toughness and durability at the primary contact and wear points. The sheathing also provides friction or stiction that helps reduce rattle. To properly set up the sheathing, do the following:
    1. Set housing preload to minimize rattling: Ensure you have more housing inside the frame than you think you need. Do this by pushing the housing from the head tube port end of the frame into the down tube. You want to do final assembly with the housing pushing against the inside wall of the down tube. Why? This pressure or preload prevents the housing from rattling. The friction provided by the shrink sheath helps maintain housing contact with the inside of the down tube.
    2. Start by marking the housing at the entry and exit port points with a non-black paint pen.
    3. Cut about a 9 cm length of the appropriate diameter sheathing. Cut one for each entry and exit port.
    4. Complete the rear port sheathing and heating process before doing the front entry port sheathing process.
    5. Center the shrink sheath length to the paint mark you made.
    6. Heat the sheathing with the heat gun.
    7. Let the sheathing cool down to room temperature.
    8. Center the sheathing to the ports. Remember that for head tube ports, set the housing so that there is preload on the housing inside the down tube as described above.
    9. You can set the chainstay internals using the same process as the down tube preload. However, chainstay housing rattle is much less common.
    10. Complete bike assembly as normal.

Fork installation: This step is the most critical of a lot of critical steps. Doing this improperly or skipping these steps can lead to fork failure and injury or death.

Note: The housings will rub against the steerer. This is normal.

  1. Install the headset race.
  2. Apply a layer of Gorilla Tape covering the circumference of the steerer tube where the housing will rub the steerer. Be generous with the height of tape you apply. The purpose of this tape is to help protect the steerer from wear. This step and the next step are critical to ensure that the brake/shifter housing will not wear away at the steerer can cause a catastrophic failure.
  3. Apply a frame protector pad at each contact point where the housings run inside the head tube. This step helps keep the steerer from experiencing wear at the housing interfaces. Check for wear of the frame protectors, tape, and heat shrink protectors every 2,500 miles.

Maintenance

As you would do with any other internal routing, replace all the housing every 2,500 miles or at least annually depending on how many hours the owner rides, the weather and climate conditions, and how tough on equipment the rider is.

Periodically check the wear points of the system: Anywhere friction or rubbing occurs:

  • Fork steerer and housing contact point
  • Anywhere there's heat shrink sheathing installed
  • Entry and exit ports
  • Inside the bottom bracket shell at the shell's breather holes and the contact point between housing and the bottom bracket cartridge sleeve

If any parts are worn, replace them.

Troubleshooting

Bottom bracket fit

The trickiest part of setting up Seven's internal routing system — and one of the things that makes it so much better than many metal bike internal systems — is that it really is internal, and that means it runs through the bottom bracket (BB) shell. That's a tight fit. There are two tricks to making this easy:

  • Ensuring housing preload usually helps with maximizing the tangent angle at which the housing enters and exits the bottom bracket. Increase or decrease housing preload to help improve the angle around the BB cartridge sleeve
  • Make the right bottom bracket choice. There are a few reputable brands. Some fit more easily than others. Review the table below:

Difficulty rating to install the bottom bracket after installing the internal routing:

T47 Bottom Bracket Brand Single
Internal Housing		 Double
Internal Housing		 Triple
Internal Housing
Chris King Easiest Easy Moderate
Wheels Manufacturing Easiest Easy-ish Moderately challenging
Praxis Moderate Challenging Requires a different sleeve of smaller diameter. Wheels Manufacturing or similar works well.

Our comments and rating regarding routing difficulting are not a reflection of manufacturing quality. These bottom bracket designs weren't necessarily intended to facilitate internal routing.

Fork steerer friction

Steerer turning friction is normal. The head tube internal housing will brush the fork steerer. This creates nominal friction on the freedom of fork turning. You will notice this, but it will not impact steering performance. This interference fit is required in order for the internal system to work properly. Depending on the fork model and the requested internal routing design, the friction level will vary. Some forks have minimal drag, and some are more noticeable. While this is unusual, it allows Seven to provide the most durable and aero internal system available. The tradeoff is well worth it.

Housing rattle

If the bike is initially set up to Seven's standards, rattle shouldn't occur. However, over time, it may creep into the system. One of the benefits of using the heat shrink sheath is that it creates friction at the port. This friction helps keep tension on the housing. If you're getting rattling, it is 90% likely it's occurring in the down tube. If so, push the housing into the port to create slack in the system. This forces the housing against the inner tube wall. With enough slack and force, the housing can't rattle. The friction of the sheathing will help keep the housing in place. While we like this method, rattle is common for many internal routing systems. Look online for the various ways to eliminate rattle. Choose the solution you like best.