Park Tool BBT-18 8-Notch Bottom Bracket/Lockring Tool for Shimano Octalink, ISIS Drive, Bosch Gen 3 and 4, Brose, etc. The BBT-18 is a heavy duty, investment cast tool for installing and removing the following eight-notch bottom bracket cups: Shimano Octalink right side bottom bracket cups with external notchesISIS Drive bottom bracket cups including Truvativ and BontragerFront chainring lockring for Bosch Gen 3 and Gen 4 e-bike systemsFront chainring lockring for Specialized Levo Brose e-bike systems Constructed from investment-cast steel and featuring 36mm wrench flats. The BBT-18 has 8 notches with a nominal outside diameter of 43.4mm. The hole in the center of the casting is 22.5mm, and will not fit over 30mm spindles. Manufactured by Park Tool, the most trusted name in bicycle tools and repair equipment for over 50 years. Park Tool BBT-18 8-Notch Bottom Bracket/Lockring Tool for Shimano Octalink, ISIS Drive, Bosch Gen 3 and 4, Brose, etc. The BBT-18 is a heavy duty, investment cast tool for installing and removing the following eight-notch bottom bracket cups: Shimano Octalink right side bottom bracket cups with external notchesISIS Drive bottom bracket cups including Truvativ and BontragerFront chainring lockring for Bosch Gen 3 and Gen 4 e-bike systemsFront chainring lockring for Specialized Levo Brose e-bike systems Constructed from investment-cast steel and featuring 36mm wrench flats. The BBT-18 has 8 notches with a nominal outside diameter of 43.4mm. The hole in the center of the casting is 22.5mm, and will not fit over 30mm spindles. Manufactured by Park Tool, the most trusted name in bicycle tools and repair equipment for over 50 years. Park Tool: Always a Perfect Fit As with every other component found on a bicycle, Park Tool offers a full line of tools for bicycle lockring chainrings, including many of the most popular modular crank and e-bike chainring standards: Park Tool: Always a Perfect Fit As with every other component found on a bicycle, Park Tool offers a full line of tools for bicycle lockring chainrings, including many of the most popular modular crank and e-bike chainring standards: BBT-18 Chainring Lockring & Bottom Bracket Tool LRT-1 Chainring Lockring Tool LRT-3 Chainring Lockring Tool BBT-22 Bottom Bracket Tool Buying Options Add to Cart Add to Cart Add to Cart Customer Reviews — 4.5 out of 5 stars 48 4.6 out of 5 stars 169 4.8 out of 5 stars 1,436 Price — no data $27.95$27.95 $24.95$24.95 $23.95$23.95 Tool Fitting 8 Notches - 43.4mm Outside Diameter 8 Notches - 50mm Outside Diameter 4 Or 8 Notches - 47-48mm Outside Diameter 22 Internal Splines - 32mm Inner Diameter Lockring Compatibility Bosch Gen 3 & Gen 4 e-bikes, Specialized Levo Brose e-bikes Bosch Gen 2 E-Bikes Including Active Line (chainrings less than 20 teeth), Performance Line and Performance Line CX models Some Specialized, Cannondale and FSA modular cranks no data Bottom Bracket Compatibility Octalink, ISIS Drive, ISIS Overdrive no data no data Shimano, Truvativ, RaceFace, FSA cartridge bottom brackets Equivalent Tool no data Bosch 0275009003 Cannondale KT012, FSA E0667 no data TRUSTED SINCE 1963 Since our origins in the back of a bike shop in 1963, it has been Park Tool's sole mission to design and manufacture high-quality tools that empower mechanics and riders of all skill levels to service their bicycles. As with our other 500+ tools, our lockring tools are a product of our decades of experience and expertise in the industry, in the shop and on the trail.