How to Adjust Brake Disc Rubbing on an Arwibon Q30 Scooter

This tutorial covers brake caliper alignment and cable adjustment on an Arwibon Q30 scooter when the brake disc rubs, makes scraping or knocking sounds, or the wheel has too much resistance when spun by hand.

Tools Needed

Prepare:

• Allen key
• Small stool or support stand
• Protective gloves

Raise the wheel off the ground before adjustment so you can spin it freely and check the result.

Release the Brake Cable Tension

Step 1: Loosen the Brake Cable Clamp Bolt

Locate the brake cable clamp bolt on the brake caliper.

The official Arwibon Q30 video shows this at about 00:00.

Use the Allen key to loosen the bolt counterclockwise.

The video shows this at about 00:03.

Step 2: Remove the Brake Cable From the Caliper Arm

Pull the inner brake cable out of the caliper arm clamp.

The official video shows the cable being released at about 00:10.

Remove the protective spring from the cable and keep it nearby for reinstallation.

Releasing the cable first removes cable tension from the caliper before alignment.

Loosen the Brake Caliper

Step 3: Loosen the Two Caliper Mounting Bolts

Locate the upper and lower Allen bolts securing the caliper to the mounting bracket.

The official Arwibon Q30 video shows them at about 00:15.

Loosen the upper bolt and then the lower bolt several turns.

The video shows this beginning at about 00:16.

Do not remove the bolts completely.

Step 4: Check That the Caliper Can Move

By about 00:30 in the official video, the caliper can move slightly from side to side.

This movement is needed so the caliper can be repositioned around the brake disc.

If the caliper still cannot move, check that both mounting bolts are loose enough.

Center the Caliper Over the Brake Disc

Step 5: Position the Brake Disc Between the Pads

Hold the brake caliper with both hands.

The official video shows this at about 00:33.

Look through the caliper opening and move the caliper slightly left or right.

At about 00:36, the video shows the brake disc being centered between the brake pads.

Try to leave a similar small clearance on both sides of the disc.

The gap is shown more clearly at about 00:41.

Step 6: Hold the Caliper in Position

Once the disc is centered, keep one hand on the caliper so it does not move.

The official Arwibon Q30 video shows this at about 00:46.

Do not let the caliper shift while tightening the mounting bolts.

Step 7: Tighten the Two Caliper Bolts Alternately

Use the Allen key to tighten the upper and lower mounting bolts.

The official video shows this at about 00:48.

Tighten them gradually, moving back and forth between the two bolts.

Do not fully tighten one bolt first and then the other.

The video shows the final tightening at about 00:52.

No tightening torque is provided in the supplied procedure.

Check the Wheel Before Reinstalling the Cable

Step 8: Spin the Rear Wheel

Spin the rear wheel firmly by hand.

The official Arwibon Q30 video shows this at about 00:56.

Listen for scraping and watch how freely the wheel rotates.

At about 00:58, the video shows the wheel turning without brake grinding.

If the disc still rubs heavily, loosen the caliper bolts slightly and repeat the centering process.

Reinstall the Brake Cable

Step 9: Reinstall the Protective Spring

Slide the protective spring back onto the brake inner cable.

The official video shows this at about 01:23.

Step 10: Route the Brake Cable Through the Caliper

Pass the inner cable through the caliper adjuster and the cable-clamp area on the operating arm.

The official Arwibon Q30 video shows this at about 01:27.

Make sure the outer cable housing is correctly seated before setting cable tension.

Step 11: Remove Excess Cable Slack

Move the caliper arm forward slightly by hand.

At the same time, pull the inner cable straight to remove obvious slack.

The official video shows this at about 01:33.

Do not pull the cable so tightly that the brake pads remain applied after the lever is released.

Step 12: Tighten the Cable Clamp Bolt

Hold the cable position and tighten the cable clamp bolt.

The official Arwibon Q30 video shows this at about 01:36.

Make sure the cable cannot slip through the clamp when the brake lever is operated.

Perform the Final Brake Adjustment

Step 13: Spin the Wheel Again

Spin the rear wheel after the cable has been reinstalled.

The official video shows this at about 01:47.

At about 01:50, the wheel is checked again for brake rubbing.

The wheel should still rotate freely without heavy continuous scraping.

Step 14: Test the Brake Lever

Operate the brake lever.

The official Arwibon Q30 video shows the final brake test at about 01:53.

The brake should engage normally and release when the lever is released.

Spin the wheel again after releasing the lever to confirm the brake is not staying partially applied.

Fine Adjustment With the Barrel Adjuster

If the caliper is centered but the brake still needs a small cable-tension correction, use the cable barrel adjuster.

Small adjustments can change lever travel without repeating the full caliper alignment.

If turning the adjuster causes the brake to drag, reduce the cable tension slightly.

Do not use the barrel adjuster to compensate for a visibly misaligned caliper.

Important Notes

Release the Brake Cable Before Centering the Caliper

The supplied procedure disconnects the cable before caliper alignment.

This removes tension from the operating arm and makes it easier to position the caliper around the disc.

Tighten the Caliper Bolts Alternately

Do not fully tighten one mounting bolt while the other remains loose.

Alternating between the upper and lower bolts helps prevent the caliper from shifting during tightening.

Do Not Overtighten the Brake Cable

When reinstalling the inner cable, remove obvious slack but do not preload the caliper enough to keep the pads touching the disc.

The wheel should still turn freely when the brake lever is released.

Check the Brake Disc if Rubbing Continues

If the caliper is centered but the brake disc rubs only at one point during each wheel rotation, the supplied adjustment procedure may not solve the problem completely.

A bent or uneven brake disc should be inspected separately.

Final Check

After adjustment, confirm that:

• the caliper is secure;
• the brake disc sits between the pads;
• the wheel spins without heavy continuous rubbing;
• the brake cable is correctly seated;
• the cable clamp bolt is secure;
• the brake lever engages normally;
• the brake releases after the lever is released;
• the wheel still turns freely after the final brake test.

Perform the first riding check at low speed and test the brake before normal riding.

This procedure follows the official Arwibon Scooter video “Q30 Brake Friction Sound Adjustment | Arwibon Q30” and covers brake cable release, caliper centering, cable reinstallation, and final brake testing shown for the Arwibon Q30 scooter.