The Shimano INTER-8 Internal Geared Hub is a reliable and efficient drivetrain component designed for road, city, trekking, and e-bikes. Unlike traditional derailleur systems, internal geared hubs provide smooth shifting, low maintenance, and increased durability. Proper installation, adjustment, and maintenance are essential to ensure optimal performance and longevity. This guide covers everything from setting up the hub to maintaining it for long-term use.
Tools Required
To install and maintain the Shimano INTER-8 hub, the following tools are necessary:
- 3 mm hexagon wrench
- 4 mm hexagon wrench
- 10 mm spanner
- 15 mm spanner
- Adjustable wrench
- TL-S700-B (Shimano setting tool)
- TL-LR10 (Shimano lockring tool [paid link])
Installing the Shimano INTER-8 Internal Geared Hub
The installation process begins with mounting the sprocket onto the hub. The sprocket is held in place by a snap ring, which secures it onto the driver. Before proceeding, it is important to ensure that the right-hand dust cap is installed correctly. Once the sprocket is positioned, the snap ring should be fitted securely into the designated groove. For a clean installation, ensure the chain is in good condition—refer to How to Replace Your Bike Chain if a new chain is needed.
The next step involves attaching the cassette joint, which plays a crucial role in shifting functions. The cassette joint pulley should be rotated to align the red marks on both the pulley and the bracket. With the marks properly aligned, the cassette joint can be slid onto the hub until the red marks on both components match. Finally, the cassette joint fixing ring should be rotated 45° clockwise to secure the connection.
Installing the hub onto the bike frame requires proper positioning of the chain and axle. Before setting the hub axle into the rear dropout, the chain must be correctly mounted onto the sprocket. Non-turn washers should be placed on both sides of the hub axle, ensuring that their protrusions align with the grooves in the dropout. The cassette joint should then be positioned parallel to the chainstay. The installation is completed by tightening the cap nuts to a torque specification of 30–45 N·m. If your drivetrain has been in use for a while, checking for wear is crucial—see Top 5 Signs Your Drivetrain Needs Maintenance for helpful tips.
The final installation step involves mounting the shifter and shifting cable. The shifter should be attached to a section of the handlebar with a diameter of Φ22.2 mm. Once the shifter is in place, the inner cable should be inserted through it, ensuring that the sealed outer cap remains at the shifter end. The cable must be routed through the outer casing and secured at the cassette joint pulley by properly aligning the inner cable mounting nut. After installation, shifting functionality should be tested to confirm smooth movement across all eight gears.
Adjusting the Shimano INTER-8 Internal Geared Hub
Proper adjustment of the cassette joint is crucial for maintaining smooth and precise gear shifts. The adjustment process begins by shifting the system to gear 4. At this point, the yellow setting lines on both the cassette joint bracket and pulley should be inspected to ensure they are perfectly aligned.
If the setting lines are misaligned, adjustments can be made using the cable adjustment barrel. Turning this barrel will modify the cable tension, helping to bring the setting lines into alignment. Once the initial adjustment is complete, it is essential to shift the system back to gear 8 and then return to gear 4 to confirm that the alignment remains accurate. If necessary, minor readjustments can be made until the lines remain correctly positioned throughout the shifting process. If you experience issues with gear shifting, refer to Troubleshooting Common Gear Shifting Problems on Your Road Bike for further guidance.
Maintaining the Shimano INTER-8 Internal Geared Hub
Regular maintenance is key to ensuring the longevity and performance of the Shimano INTER-8 hub. One of the most common maintenance tasks is replacing the indicator unit, which provides a visual reference for gear selection. To replace the unit, the shifter must be set to gear 8 before removing the cover fixing screws. Once the screws are removed, the indicator unit can be carefully lifted off. When installing a new unit, it should be positioned so that the alignment pin fits into the hole of the winder unit. The cover fixing screws should then be reinstalled and tightened to a torque specification of 0.3–0.5 N·m.
In addition to indicator unit replacement, Shimano recommends oil maintenance at least once a year or after 2,000 km of riding. The oil inside the hub serves to lubricate the internal gears, reducing friction and preventing premature wear. The oil maintenance process begins by draining the old oil. This is done by rotating the wheel until the oil port faces upward, at which point the oil port screw and O-ring can be removed using a 3 mm hex wrench. A bleed nipple is then attached to the hub shell, allowing oil to be drawn out using a syringe.
After the old oil is removed, the hub must be cleaned by flushing it with fresh Shimano WB maintenance oil. Approximately 25 ml of oil should be injected into the hub, after which the wheel should be rotated for one minute. The hub should then be left stationary for another minute before draining out the flushing oil.
To complete the oil replacement, 25 ml of new Shimano WB maintenance oil should be injected into the hub. The oil port screw and O-ring should then be reinstalled and tightened to 2–3 N·m. After refilling, shifting functionality should be tested by running through all gear positions while rotating the pedals. Any excess oil on the exterior of the hub should be wiped clean to prevent contamination. If you are performing a full drivetrain service, consider checking your chain for stretch—see How to Replace a Stretched Chain Without Damaging Your Drivetrain.
Performing regular maintenance ensures that the Shimano INTER-8 hub continues to provide smooth and efficient performance for many miles.