The Yokozuna Ultimo Hy/Mech [paid link] brake set represents a unique hybrid braking system that merges cable-actuated levers with hydraulic caliper performance. This dual mechanism allows for seamless integration into mechanical drivetrain systems while delivering the responsive feel of hydraulic braking. Its design is targeted toward road cyclists seeking enhanced stopping power without a complete hydraulic system overhaul.

Tools Required:

• 5mm hex wrench
• 2.5mm hex wrench
• Torque wrench (2–6 Nm range)
• Cable cutters
• Hydraulic mineral oil
• Bleed kit (compatible with Yokozuna hydraulic systems)
• Rotor truing tool
• Isopropyl alcohol and clean rags

Installation of the Ultimo Hy/Mech Brake Set

Mounting the Calipers

The Ultimo Hy/Mech calipers follow the flat-mount or post-mount standard, depending on your frame’s specifications. Begin by aligning the caliper onto the frame or fork. Ensure the pads are centered over the rotor and use a torque wrench to secure the bolts to the manufacturer’s recommended torque values. Incorrect torque can result in brake noise or failure under load.

Connecting the Cable

Unlike full hydraulic systems, the Ultimo accepts standard mechanical brake cables. Feed the inner cable through the lever and into the Yokozuna caliper’s actuator arm. Maintain tight cable tension while securing the cable pinch bolt. Excess slack leads to spongy brake feel, while overtightening could deform the actuator.

Aligning the Rotor and Pads

Once the caliper is in place, spin the wheel and actuate the brake lever. The rotor should spin freely without pad rub. If contact occurs, adjust the caliper position slightly. Check pad alignment through the caliper window—both pads should contact the rotor evenly during braking.

Adjustment Procedures

Pad Contact and Feel

The hybrid nature of the Ultimo allows for nuanced adjustment. The caliper features an internal cam system that manages hydraulic push-off. While the lever throw is cable-based, fine modulation is still achieved through piston contact points. If the lever travel feels excessive, inspect the barrel adjuster and re-check cable tension.

Rotor Clearance

Brake rub is a frequent issue in hybrid systems due to frame flex or pad movement. Use a rotor truing tool to eliminate minor rotor deviations. If clearance issues persist, reassess the caliper mounting or consider re-bleeding the hydraulic chamber to recalibrate piston spacing.

Maintenance Guidelines

Routine Maintenance

Despite its mechanical lever interface, the Ultimo Hy/Mech requires regular hydraulic system checks. Examine hydraulic fluid levels monthly, and re-bleed the system every 12–18 months or when performance declines. Always use Yokozuna-compatible mineral oil, as incompatible fluids will degrade seals and performance.

Pad and Rotor Wear

Monitor pad wear every 1000 km and rotor thickness every 2000 km. Replace pads when the compound wears down to 1mm. Rotor thickness below 1.5mm may compromise braking force and should be addressed immediately. Clean rotors with isopropyl alcohol after rides in wet or gritty conditions.

Troubleshooting Common Setup Issues

Soft Lever Feel

If the lever pulls to the bar with little braking effect, inspect for air within the hydraulic circuit. Air bubbles impede hydraulic transfer and must be removed using a proper bleeding procedure. Ensure the master cylinder is adequately filled and that bleed port screws are sealed post-service.

Brake Squeal

Noise under braking typically results from contamination or improper pad bedding. Clean both the rotor and pad surfaces thoroughly. If the issue persists, re-bed the pads by executing a series of slow, firm stops from 25 km/h to warm up and evenly embed pad material onto the rotor surface.

Inconsistent Pad Retraction

Occasional pad drag may result from a sticky piston or worn seals. Apply a light coat of hydraulic fluid to the piston edges to restore smooth movement. If symptoms persist, a piston rebuild or full caliper service may be necessary.

Customization and Performance Optimization

Lever Choice and Ergonomics

The Ultimo is compatible with most drop-bar mechanical brake levers. Riders can customize lever feel by pairing with high-leverage models or short-pull levers based on preference. Barrel adjusters allow on-the-fly modulation adjustments without tools.

Rotor Size Selection

While the default rotor size is 160mm, upgrading to 180mm rotors can improve heat dissipation for riders tackling long descents. However, frame and fork compatibility must be verified to avoid overstressing mounts.

Cable Optimization

High-compression, lubricated brake housing (such as Yokozuna Reaction cables) significantly enhances lever response. Avoid generic housings that introduce friction and delay braking response, especially under wet conditions.

Comparison with Similar Brake Sets

Ultimo Hy/Mech vs. TRP HY/RD

Both systems operate with mechanical input and hydraulic output. However, the Ultimo offers a more compact, lighter design and higher pad retraction force. Riders have also noted better modulation from the Ultimo, especially when paired with quality cables.

Ultimo Hy/Mech vs. Juin Tech GT-F

Juin Tech calipers are often more budget-friendly, but they generally offer lower hydraulic power. The Ultimo is better suited for performance road or gravel applications, offering greater stopping power and serviceability.

Compatibility Considerations

Drivetrain Integration

The Ultimo brake set integrates seamlessly with mechanical groupsets from Shimano, SRAM, and Campagnolo, provided they use short-pull cable actuation. It is not compatible with full hydraulic levers or long-pull mountain bike levers.

Rotor and Pad Standards

The system uses standard 6-bolt or center-lock rotors and common flat-mount pads, making sourcing and replacements easier. Ensure all components conform to the required specifications to prevent braking inconsistency or damage.

Frequently Asked Questions

1. Can I use the Ultimo Hy/Mech with Shimano STI levers?
Yes. The system is designed to work with Shimano’s mechanical STI levers as long as they are short-pull and match the braking cable pull profile.

2. How often should I bleed the hydraulic section of the brake?
Every 12 to 18 months is ideal, or any time the brake feel becomes spongy or inconsistent.

3. What type of fluid does the Ultimo use?
Only use Yokozuna-compatible mineral oil. Never substitute with DOT fluid, as it will degrade the seals.

4. Do I need to upgrade my rotors for better performance?
It depends on your riding. 160mm rotors are sufficient for most road use. Larger rotors help with heat management on long descents.

5. Is this brake set suitable for gravel riding?
Yes. The Ultimo Hy/Mech provides excellent braking power and modulation for gravel and mixed terrain, especially when paired with wider tires and robust rotors.

6. Are there any special considerations during winter storage?
Store the bike upright and in a temperature-stable environment. Check the caliper for leaks before the first spring ride and perform a bleed if needed.

Conclusion

The Yokozuna Ultimo Hy/Mech brake set stands out as a robust and innovative solution for cyclists seeking hydraulic performance within a mechanical setup. Its hybrid nature simplifies installation while enhancing braking feel and reliability. With routine care, correct setup, and thoughtful upgrades, this brake system will provide consistent, powerful stopping in all conditions.