Key benefits Saves time and reduces effort when removing or installing main shaft / bottom bracket bearings. Protects the bottom bracket ring and surrounding components from damage during service. Durable construction resists deformation and stands up to repeated workshop use. What it does Designed to pull and install main shaft bearings on drive spindles and bottom bracket rings. Improved gripping geometry and access allow secure engagement with the bearing and the bottom bracket’s interior, making removal and installation easier and more controlled. Compatibility Compatible with Big 5 and 6-speed transmissions from 1984. Use only with the specified models to ensure proper fit and performance. Material and performance Made from high-quality, durable metal to withstand the leverage and stresses of bearing removal and installation. Robust construction minimizes bending or deformation under load, providing reliable performance over repeated jobs. Practical advantages Faster bearing repairs and replacements compared with improvised tools or unsuitable pullers. Easier access to the bottom bracket interior reduces the chance of slipping or scratching fragile components. Designed for repeatable, controlled operation to help maintain component integrity and reduce rework. Typical use scenarios Vintage bicycle restoration: remove and replace worn main shaft bearings on a 1984 Big 5 or 6-speed drivetrain during a full restoration. Bicycle shop maintenance: routine service and bearing replacement on customer bikes with 1984 Big 5/6-speed transmissions, improving throughput and reducing risk of damage. Home mechanic repair: safely remove a seized bearing from the drive spindle or bottom bracket ring without resorting to destructive methods. What to expect in use Secure grip on bearings and easier access to the bearing seat for clean extraction and installation. A tool intended specifically for the stated compatible models; pairing it with the correct transmission model ensures optimal fit and performance. Note Confirm the transmission model and year (Big 5 or 6-speed, 1984) before purchase to ensure compatibility.