kuukiatu wo kakuninsite, nando mo sizyousita sueni, dendouasisutozitensya wo katta.

Yes. 空気圧 literally means air pressure, and in this context it most naturally means the tire pressure of the bicycle.

Japanese often leaves out words that are obvious from context, so instead of saying something like タイヤの空気圧, the sentence just says 空気圧.

The て-form is being used to connect actions.

So 空気圧を確認して、何度も試乗した末に、...買った means something like:

• checked the air pressure,
• and then test-rode it many times,
• and after all that, bought it.

Here, 確認して links the first action to what follows. It does not necessarily mean the actions happened immediately one after another, just that they are part of the sequence.

何度も means many times or over and over.

The も adds the sense of repetition or emphasis. Compare:

• 何度 = how many times / how often
• 何度も = many times, repeatedly

A very natural English translation here is after test-riding it many times.

You will also often see 何回も, which is very similar.

試乗する means to take something for a test ride or to try riding it before buying. It is commonly used for vehicles such as cars, motorcycles, and bicycles.

So:

• 乗る = to ride
• 試乗する = to test-ride

In this sentence, 試乗した tells you the speaker was not just riding the bicycle normally—they were trying it out before deciding whether to buy it.

Because 末に is a grammar pattern that normally attaches to a past/plain form verb or to a noun phrase.

The pattern is:

• Verb past form + 末に
• Noun + の + 末に

So:

• 何度も試乗した末に = after test-riding it many times; after much test-riding

Using 試乗して末に would not fit this pattern.

～た末に means something like:

• after a long process
• after much effort/thought
• in the end, after all that

It is not just a neutral after. It suggests that something took time, repetition, or consideration, and then a final result was reached.

So 何度も試乗した末に、電動アシスト自転車を買った has the nuance of:

After test-riding it many times and carefully considering it, I finally bought an electric-assist bicycle.

This pattern often sounds a bit more formal or written than simpler expressions like 後で or てから.

In 末に, the に is part of the set expression. It marks the point reached at the end of a process.

So you should think of 末に as one chunk meaning:

• at the end of
• after
• in the end, following

It is better to learn 末に as a whole grammar pattern rather than trying to interpret the に separately every time.

Yes. It is a compound noun.

It breaks down like this:

• 電動 = electric / motorized
• アシスト = assist
• 自転車 = bicycle

So 電動アシスト自転車 means an electric-assist bicycle, often called an e-bike in English.

Japanese often stacks nouns together like this, especially in product names and technical descriptions.

It is omitted because it is understood from context.

Japanese very often leaves out objects when they are obvious. Here, the speaker is talking about buying 電動アシスト自転車, so the listener naturally understands that what was test-ridden was the bicycle, or possibly several bicycles of that type.

So the sentence does not need to explicitly say:

• 電動アシスト自転車を何度も試乗した

because that information is already clear enough.

Because both actions are being described as completed events in the past.

Also, in ～た末に, the past form is required as part of the grammar pattern. So 試乗した is not just random tense choice—it is part of 試乗した末に.

The overall timeline is:

1. checked the air pressure,
2. test-rode it many times,
3. finally bought it.

So using past forms here is completely natural.