zìxíngchē bàotāi le, bié mǎshàng shāchē.

爆胎 is a common expression meaning to have a tire burst / to get a blowout.

Grammatically, it behaves like a verb phrase:

• 爆 = burst
• 胎 = tire

So 自行车爆胎了 means the bicycle has had a tire blowout. In everyday Chinese, this is a very normal way to talk about a sudden flat tire.

Here, 了 shows that a new situation has happened and is now relevant.

So 爆胎了 does not just describe the idea of a blowout; it means:

• the blowout has happened
• this is the current situation
• the next instruction follows from that situation

That is why it fits well before the warning 别马上刹车.

Without 了, the sentence would sound less like an immediate real-world event.

Both are correct, but 自行车爆胎了 is shorter and very natural.

Chinese often lets the whole vehicle be the subject with 爆胎:

• 汽车爆胎了
• 摩托车爆胎了
• 自行车爆胎了

Even though it is really the tire that bursts, the sentence is normally phrased as the vehicle had a blowout.

If you say 自行车的轮胎爆了, that is more explicit, but not necessary.

Usually 爆胎 suggests a sudden burst or blowout, not just any loss of air.

So it is stronger than simply saying the tire is flat.

Other related expressions are:

• 轮胎没气了 = the tire has no air
• 轮胎漏气了 = the tire is leaking air
• 扎胎了 = the tire got punctured

In this sentence, 爆胎 fits well because the advice is about what to do immediately after a sudden dangerous problem.

别 is the normal way to make a negative command in spoken Mandarin.

So:

• 别马上刹车 = don’t brake immediately

Important differences:

• 不 usually negates statements, not commands
• 不要 can also mean don’t, and 不要马上刹车 is correct
• 别 is shorter and very common in warnings and instructions

So 别 sounds very natural here.

马上 means immediately / right away.

Chinese adverbs usually come before the verb, so:

• 马上刹车 = brake immediately
• 别马上刹车 = don’t brake immediately

That word order is standard:

• 别
  • adverb
    • verb

So the sentence is not saying don’t use the brakes at all. It is specifically saying don’t brake right away.

It can be both.

As a noun:

• 刹车 = brake

As a verb:

• 刹车 = to brake

In this sentence, it is a verb:

• 别马上刹车 = don’t brake immediately

This is very common in Chinese: the same word can function as different parts of speech depending on context.

Also, in 刹车, the character 刹 is pronounced shā, so the word is shāchē.

Yes, it is omitted because it is obvious from context.

The full idea is something like:

• 自行车爆胎了，你别马上刹车。

But in Chinese, commands and advice often leave out the subject when it is clear. That makes the sentence sound more natural and direct.

So the understood meaning is:

• If your bicycle has a blowout, don’t brake immediately.

The sentence has two parts:

1. 自行车爆胎了

   • gives the situation

2. 别马上刹车

   • gives the advice or instruction

So the pattern is basically:

situation + advice/command

This is a very common Chinese structure. The first clause sets the context, and the second clause tells the listener what to do.

The comma helps separate those two parts clearly.

Yes. Here are some natural alternatives:

• 自行车爆胎了，不要马上刹车。
• 自行车轮胎爆了，别立刻刹车。
• 车胎爆了，先别急着刹车。

These all express a similar idea, but with slightly different tone:

• 别 is shorter and more conversational
• 不要 is a bit fuller
• 立刻 is similar to 马上
• 先别急着刹车 adds the sense of don’t rush to brake

So the original sentence is natural, concise, and very typical for a warning.