The Campagnolo Ultra-Torque Bottom Bracket [paid link] is known for its efficient power transfer, low weight, and robust design. However, like any high-performance component, it demands precise installation and adjustment. While the Ultra-Torque system itself doesn’t have conventional “limit screws” in the way derailleurs do, it does rely on critical preload and fit tolerances that function similarly—controlling axial movement, crank alignment, and bearing pressure. Misadjustments here can compromise the bottom bracket’s longevity and the drivetrain’s overall feel.
This article will walk you through how to correctly address the preload and assembly tolerances of the Ultra-Torque system, with a focus on getting “limit screw-style” adjustments just right for optimal performance and longevity.
Understanding the Role of Preload in Ultra-Torque Systems
Campagnolo’s Ultra-Torque bottom bracket [paid link] design uses a central Hirth joint and fixed cups to integrate both crank arms securely. What mimics a “limit screw” function is the ultra-critical preload created during crankset installation, primarily affected by:
- The wave washer on the non-drive side
- Bearing fit and torque values
- Cup interface and frame shell preparation
When not set correctly, this preload may lead to excessive axial play or, conversely, binding and premature bearing wear.
Tools Required
- Torque wrench [paid link] (4mm and 10mm hex bits)
- Campagnolo Ultra-Torque bearing removal/installation tools
- Bottom bracket cup tool (Campagnolo-specific)
- Grease and threadlocker
- Caliper or feeler gauge (optional but recommended for measuring bearing clearance)
- Soft mallet
Wave Washer Function and “Limit-Like” Behavior
The wave washer on the non-drive side acts similarly to a limit screw. It’s a compression spring that maintains constant pressure to eliminate play between crank arms and bottom bracket cups. However, if the crank arms are not torqued correctly, or if the washer is not seated properly, the system can become either too loose or overly tight.
Here’s what to check:
- Too much play: Indicates the wave washer is not sufficiently compressed, or crank arm bolts are under-torqued.
- Resistance or binding: Suggests over-compression, misaligned bearings, or frame shell distortion.
Correcting the Ultra-Torque Axial Load (The “Limit” Adjustment)
Proper limit-style adjustment in an Ultra-Torque setup depends on these three elements being precisely controlled.
1. Bottom Bracket Cup Installation
- Thread both cups into a clean, properly faced frame shell.
- Use a torque wrench [paid link] to tighten the cups to 35-40 Nm.
- Avoid over-torquing, as this may distort the interface and lead to axial load misalignment.
2. Crank Arm Assembly and Wave Washer Seating
- Slide the drive-side crank arm through the bearing cups.
- Install the wave washer on the non-drive side spindle.
- Insert the non-drive crank arm onto the spindle. Ensure the Hirth joint is aligned.
Critical Point: Before tightening the fixing bolt, the wave washer should show light compression but not be fully flattened. This ensures correct preload.
3. Fixing Bolt Torque
- Tighten the central bolt connecting the two crank arms to 42-60 Nm.
- Use a torque wrench [paid link] with a 10mm hex key to achieve the specified value.
- Watch for compression of the wave washer—ideally, it should retain some spring.
4. Test Axial Play
- Once installed, test the crankset for lateral movement.
- There should be no noticeable play, but the cranks must spin freely.
- If resistance is felt, inspect for overtightened bearing cups or improperly compressed wave washer.
Common Adjustment Mistakes to Avoid
Overtightening Crank Bolt
Excessive torque can compress the wave washer fully, increasing bearing friction and reducing bearing life.
Improper Washer Position
Installing the wave washer on the drive side or omitting it altogether can lead to total system failure. Always verify its position before final tightening.
Cup Misalignment
Installing cups into a poorly faced bottom bracket shell can induce asymmetrical pressure on the bearings. This mimics a misadjusted limit screw by applying inconsistent preload.
Advanced Fine-Tuning Techniques
Experienced mechanics may measure the gap between crank arms and cups with feeler gauges to ensure consistent spacing. Others check for bearing drag post-installation to confirm preload correctness.
If you’re repeatedly encountering axial play, consider inspecting for:
- Deformed wave washer
- Worn Hirth joint splines
- Crank bolt fatigue
Signs Your Limit-Style Adjustments Are Incorrect
- Clicking or creaking during pedal strokes
- Notchy spinning of the crank arms
- Rapid bearing wear or bearing side leakage
- Visible crank arm gap inconsistencies
All these indicate improper wave washer preload or incorrect crank bolt torque—recheck all assembly steps and replace the washer if fatigued.
FAQs
Q1: Does the Ultra-Torque bottom bracket [paid link] have actual limit screws?
No, but the preload system via the wave washer functions similarly in maintaining proper crank alignment.
Q2: How tight should the crank bolt be?
Between 42-60 Nm. Use a torque wrench to ensure accurate tightening.
Q3: What happens if I forget the wave washer?
It results in severe crank arm play, misalignment, and potential failure of the bottom bracket system.
Q4: Can I reuse the wave washer?
Yes, but if it appears flattened, bent, or fatigued, it should be replaced.
Q5: Why does my crankset feel stiff after installation?
Overcompression of the wave washer or misalignment of bottom bracket cups is the likely cause.
Q6: Do I need to grease the crank bolt threads?
Yes, apply a light coating of grease or threadlocker to ensure smooth tightening and prevent corrosion.
Conclusion
While the Campagnolo Ultra-Torque Bottom Bracket doesn’t use traditional limit screws, understanding and managing its preload system is essential for optimal function. The wave washer, bearing interface, and torque application must all work in harmony to ensure the system is tight but friction-free. Small missteps in preload adjustment can have outsized effects on performance and component lifespan. By following the steps outlined in this guide, riders and mechanics can fine-tune their Ultra-Torque setup with confidence and precision.