Repair guides › Brakes

Set up a gyro (detangler)

A rotor at the headset that lets the handlebars spin 360° (barspins) without twisting the rear brake cable. The brake lever cable splits into an upper cable to a top plate. The plate sits on bearings around the steerer, and a lower cable runs from a lower plate to the U-brake. Turning the bars rotates the plates without pulling the cable. Both cables must be the same tension or the brake feels sticky.

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Tools

• Ball-end hex key set (1.5–10 mm): Park Tool HXS-1.2 Professional L-Shaped Hex Set ($$)
• JIS #2 screwdriver: Vessel Megadora JIS screwdriver #2 ($)
• Cable & housing cutter: Park Tool CN-10 ($$)
• Brake + shift cable/housing kit: Jagwire Sport brake + shift cable kits ($$)
• Cable puller ("fourth hand"): Pedro's Cable Puller ($$)
• Housing awl / pick set: GEARWRENCH 5 pc. hook and pick set 3121D ($)

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Steps

1. Fit the gyro between headset and stem (or with the stem spacer kit for your frame).
2. Attach the lower cable from the lower plate to the U-brake. Leave it slightly slack for now.
3. Fit both upper cables from the splitter (just below the lever) to the two posts on the top plate.
4. Use the barrel adjusters on each upper cable until the top plate sits perfectly level and both cables have the same tension.
5. Take up slack at the U-brake with the main barrel adjuster.
6. Spin the bars a full turn several times: the brake should not drag or pull on.

Diagram

Signs it needs doing

• Brake feels uneven or sticks on (upper cables unequal)
• Plates tilt or click when turning
• Cable rubs the frame on barspins