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Troubleshooting

NIU KQi3 Pro, Max and Sport: flat tire or tire keeps losing air

The KQi3 uses tubeless 9.5 x 2.5 tires. NIU's answer to a puncture is a new tire, fitted by you or a service partner, kept at 45 to 50 psi.

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Your KQi3 tire goes soft between rides or goes flat. The KQi3 uses wide tubeless tires (FAQ), and the replacement tire is 9.5x2.5 (NIU tires for KQi3). The short answer: a puncture or a slow leak in the tire. The fix for a puncture is to replace the tire.

The motor is in the rear wheel on the KQi3 (NIU KQi2 vs KQi3), so a rear tire job means working around the motor cable. Power off first, never pull on the motor cable, and leave a rear wheel job to a shop if you aren't sure.

Most likely cause

A tubeless tire holds air against the rim with no inner tube, so a puncture or a leak at the bead or valve lets air out slowly or all at once. A puncture means a replacement tire or a trip to a service partner, and flat tires are not covered by warranty (NIU FAQ, NIU tires for KQi3).

Other causes to rule out

  • Low pressure. Run 45 to 50 psi and check it monthly (FAQ). Riding soft makes flats more likely.
  • A leaking valve. See tubeless tires and sealant.
  • A loose or wobbling wheel. Tighten the front and rear wheel nuts if a wheel wobbles or bounces.

How to confirm

  1. Pump to 45 to 50 psi with a gauge and check again the next day.
  2. Spray soapy water on the tread, the bead line at the rim and the valve. Bubbles show the leak.
  3. Look for a nail, glass or a cut in the tread.

Fix options

Set the pressure (easy)

If it holds once inflated, it was just low. Check it monthly. See set tire pressure.

Replace the tire (moderate to difficult)

NIU sells a KQi3 tire in standard and self-healing versions (NIU tires for KQi3). Fit it with professional tools, inflate to about 90 PSI the first time until the bead seats with two loud bangs, then let it down slowly to about 45 PSI. Check the tire's own sidewall rating before you go that high, and if you aren't confident, let a shop seat it. Other KQi tires are on NIU's spare parts page. For the rear wheel, see fix a flat on a rear hub motor wheel.

Use a service partner (pro)

A NIU service partner can replace the tire for a fee (NIU FAQ). North American owners can request parts or service on NIU's after-sales platform.

Parts

  • Tire (NIU KQi3 9.5x2.5, standard or self-healing)

Videos

How to Change Front Tire KQI3, NIU from Scoot, Let's Go: Takes the front wheel off a KQi3 and swaps the tire, showing each step on that exact scooter.
How to Change KQI3 Rear Tire from Scoot, Let's Go: Swaps the tire on the KQi3 rear wheel, where the hub motor sits, on that exact scooter.

When to get a pro

A rear tire you can't seat, a damaged rim, or any cut or pinch in the motor cable. See flat tire, e-scooter maintenance and NIU scooter troubleshooting.

Sources

Stuck after these checks? Find a shop near you.

Need a pro?

If these steps didn't fix it, find a shop near you in our partner network. For battery or wiring trouble, look for shops marked Battery and electrical.

Talk

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