Replacement of a nipple in the wheel of a Xiaomi scooter: instructions with photos and tips

Camera puncture or nipple damage is one of the most common problems for Xiaomi electric scooters: If the wheel flattens a few hours after pumping, it is the nipple (aka spool or nipple) that is to blame, and replacing it seems like a simple task, but in practice requires care: wrong actions can damage the rim or camera, and in the case of tubeless tires, make the wheel completely leaky.

In this article, you will find a step-by-step guide with nuances for different models of Xiaomi scooters (from M365 to Pro 3), a list of necessary tools and unique tips to avoid typical errors that lead to repeated punctures, and we will also discuss how to distinguish a faulty nipple from a camera puncture and when to contact the service.

Signs of a faulty nipple: how not to confuse with a puncture

Before you change the nipple, make sure it's the one that's the problem.

• 🔴 The wheel deflects 12–24 hours after pumping, but there are no visual punctures.
• 💧 When pressing the stool, a hissing sound is heard (air leakage through the valve).
• 🧼 Soap solution applied to the nipple bubbles (tightness test).
• 🔧 The slurry jams or is not fixed in the "closed" position".

If the wheel is running down instantly (in 5-10 minutes), it is likely that the camera or rim has been punctured, in which case replacing the nipple will not help. To diagnose, lower the wheel into the water, the bubbles will show the exact location of the leak.

⚠️ Note: On Xiaomi scooters with tubeless tires (such as Pro 2 or Essential), the nipple is built into the rim. its replacement requires a complete disassembly of the wheel and a special tool - do not try to pull it out with improvised means!

Tools and materials: what you need to replace

Prepare for work:

Important: For scooters Xiaomi M365/M365 Pro fit standard nipple TR-4 (as on bicycles). For models with tubeless tires (Pro 2/3, Essential) need a Presta nipple with threaded M8 — it is shorter and has a different form of base.

Step-by-step: how to replace a nipple in a chamber wheel

If your scooter is equipped with a camera bus (for example, Xiaomi M365), follow this algorithm:

1. Lower the air: Press the stool until the end to release all the air from the chamber.
2. Remove the wheel: Unscrew the mounts (usually a 15 mm nut) and carefully remove the wheel from the axle. Some models will require the removal of the motor-wheel cover.
3. Unplug the tire: 🔧 Insert the mounting blades between the rim and the tire on the opposite side of the nipple. 🔄 Carefully tuck the edge of the tire and take it out by the rim. ⚠️ Don’t use screwdrivers or knives – they will damage the camera!

Get the camera.

Replace the nipple.

• 🔩 If the nipple is fixed by a nut outside - unscrew it with a key.
• 🔄 Pull an old nipple out of the hole in the rim.
• 🆕 Insert a new nipple from inside the rim (first slid it into the hole, then lock it with a nut from the outside).

Check the position of the nipple (should sit smoothly, without distortions)

Make sure the camera is not twisted inside the tire.

Apply soap solution to a nipple for a leakproofness test

Pump the wheel to 50% pressure and check for leaks

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Tip: Before installing a new nipple, lubricate its base with soap solution - this will facilitate insertion and prevent rubber damage.

Features of replacing a nipple in a tubeless wheel

The tubeless tires (Xiaomi Pro 2/3, Essential) require a different approach, where the nipple is built into the rim and sealed with a special rubber gasket. When replacing such a nipple, be sure to use a tubeless tire sealant - without it, the wheel will not hold pressure.

Algorithm of action:

1. Remove the wheel and completely flush the air.
2. Disassemble the tire from both sides (you will need 2-3 mounting blades).
3. Get an old nipple: 🔧 Unscrew the locking nut outside the rim. 🔄 Carefully pull the nipple inside the rim (not outwards!).
4. Install a new nipple: 🆕 Put it in the hole of the rim on the inside. 🔩 Twisting the nut from the outside, but don't tug over! 🧴 Apply sealant to the base of a nipple (e.g. Stan's NoTubes).

Get the tire on.

• 🔄 Start with the side opposite the nipple.
• 💨 Pump the wheel up to 1.5-2 bar so that the tire sits on the rim.

⚠️ Warning: When working with tubeless tires, do not use a compressor - a sharp flow of air can damage the camera.

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If the tire is difficult to be boarded, lubricate the edges of the tire with soap solution - this will reduce friction and facilitate the process.

Common Mistakes and How to Avoid Them

Even experienced users make mistakes when replacing a nipple.

• 🔧 Nipple nut tug-of-war → So, you can twist the screws by hand, then you can pull the key to the screw. 1/4 turnover.
• 🔄 Wrong camera position → If the camera is twisted, the nipple will be displaced relative to the hole in the rim. Solution: Before assembly, make sure that the camera is flat, without folds.
• 💨 Pumping the wheel to maximum pressure immediately → Solution: first, put 50 percent of the pressure, check for tightness, then normalize.
• 🧴 Ignoring sealant for tubeless tires → Solution: always use a sealant when replacing a nipple in a tubeless tire.

Another common problem is rim damage when disassembling. To avoid scratches, use plastic mounting blades and do not apply excessive force. If the rim is aluminum (as on most Xiaomi scooters), deep scratches can lead to leakiness even after replacing the nipple.

How to check the leakage after replacement

After installing a new nipple, be sure to check the wheel for leaks.

1. Pump the wheel to 70-80% of maximum pressure (e.g. 2.5 bar for the Xiaomi M365).
2. Prepare a soap solution (water + dishwashing agent).
3. Apply the solution to the nipple and the junction of the tire with the rim.
4. Watch 2-3 minutes: if bubbles appear, there is a leak.

If there are no bubbles, bring the pressure to normal (usually 3.0-3.5 bar for Xiaomi scooters) and leave the wheel for 12 hours.

An additional test: put the wheel in water (for example, in a bathtub), the smallest bubbles will show even microscopic leaks that are not visible on a soap test.

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If the wheel continues to slide after replacing the nipple, the problem may be a rim crack, damage to the camera or improper assembly, in which case it is recommended to contact the service.

When is the best time to contact the service

Not all breakdowns can be repaired by yourself.

• 🔧 Nipple broke down inside the rim and you can't get it out.
• 🔄 The rim has cracks or deformities (especially important after severe blows).
• 💥 Wheel explodes when pumped (a sign of damage to the tire cord).
• 🛠️ You have a scooter with a tubeless tire, and you are not sure about your disassembly skills.

The cost of replacing a nipple in the service is 300-800 rubles (depending on the model of the scooter). If the problem is in the rim or tire, repair can cost 1500-3,000 rubles. However, in most cases, self-replacement of a nipple takes no more than 30 minutes and costs only the price of a new part (50-200 rubles).

Service tip: Look for workshops that specialize in electric scooters, not bicycles. They have experience with tubeless tires and specific Xiaomi rims.

FAQ: Frequent questions about nipple replacement