Replacing your own bottom bracket is an achievable job, provided you follow the right steps and have the right tools. The method differs depending on whether your frame is threaded or press-fit: follow this step-by-step guide to identify your standard, remove the old bottom bracket and refit the new one correctly.
Discover our range of road bike bottom brackets and road bike drivetrain groups in stock.
1. Identify your standard before you start
Before any work, it's essential to know which standard your frame uses: threaded (BSA, Italian) or press-fit (BB86, BB90, BB92, BB30, PF30). The removal method, tools, and fitting process differ entirely between standards, and using the wrong tool can damage the frame.
Good to know: if you're unsure between threaded and press-fit, see our comparison of threaded vs press-fit bottom brackets to identify your exact standard and understand their differences.
2. What tools do you need?
The tools required depend directly on the standard fitted on your frame:
- For a threaded bottom bracket: a bottom bracket wrench matching your exact standard, a torque wrench, degreaser, and thread-specific grease.
- For a press-fit bottom bracket: a press-fit bearing extractor, a press (manual or hydraulic), a mallet, and grease or mounting compound as recommended by the manufacturer.
Note: for a press-fit bottom bracket, if you don't have a press suited to your standard, it's better to take the bike to a workshop rather than improvise with unsuitable tools, at the risk of damaging the frame.
3. Steps to remove a threaded bottom bracket
- Remove the crank arms (unclipping or unbolting depending on the system: Hollowtech II, square taper, etc.).
- Position the bottom bracket wrench matching your exact standard.
- Unscrew in the correct direction: note that the unscrewing direction is reversed on the non-drive side on certain standards.
- Remove the bottom bracket and visually inspect the frame's threading.
4. Steps to remove a press-fit bottom bracket
- Remove the crank arms.
- Position the bearing extractor in the bottom bracket shell.
- Extract the bearings using the press, working progressively and symmetrically.
- Thoroughly clean the bottom bracket shell before fitting the new one.
5. Checking the frame before fitting a new bottom bracket
Before installing the new bottom bracket, check for corrosion, burrs, or deformation in the shell. Clean and degrease the whole area: this step, often overlooked, is key to preventing a brand-new bottom bracket from creaking prematurely.
Good to know: if your bottom bracket starts creaking after a few rides, our article on the causes and solutions for a creaking bottom bracket will help you diagnose the issue.
6. Steps to fit the new bottom bracket
Fitting a threaded bottom bracket
- Apply a thin layer of grease to the bottom bracket threads.
- Screw the bottom bracket in by hand to start the thread, without forcing.
- Tighten to the manufacturer's recommended torque using a torque wrench.
Fitting a press-fit bottom bracket
- Position the bottom bracket squarely in the shell, checking alignment.
- Press progressively and symmetrically using the press, without sudden movements.
- Check that there's no noticeable lateral play once the bottom bracket is fitted.
In both cases, respecting the recommended torque or fitting method directly determines the reliability and longevity of the bottom bracket over time.
7. Common mistakes to avoid
- Over-tightening or under-tightening during fitting.
- Forgetting to clean the threads or the shell before installation.
- Using a tool that doesn't exactly match your frame's standard.
- Skipping the grease or mounting compound recommended by the manufacturer.