hensokuki wo kurabe, hensokudansuu wo kakuninsita sueni, kurosubaiku wo eranda.

A natural reading is:

へんそくきをくらべ、へんそくだんすうをかくにんしたすえに、クロスバイクをえらんだ。

Word readings:

• 変速機 = へんそくき
• 比べ = くらべ
• 変速段数 = へんそくだんすう
• 確認した = かくにんした
• 末に = すえに
• 選んだ = えらんだ

No. Normal Japanese is usually written without spaces:

変速機を比べ、変速段数を確認した末に、クロスバイクを選んだ。

The spaces in your example were probably added just to make it easier for learners to see the parts of the sentence.

The sentence breaks down like this:

変速機を比べ、
= comparing the gear systems,

変速段数を確認した末に、
= after checking the number of gears / after going through that process,

クロスバイクを選んだ。
= chose a cross bike.

So the main action is 選んだ. Everything before it explains the process that led to that choice.

比べ is the stem / 連用形 of 比べる, and it can connect to the next clause in written Japanese.

So:

• 変速機を比べ、変速段数を確認した末に… is a slightly more compact, written-style way to connect actions.

You could also say:

• 変速機を比べて、変速段数を確認した末に…

That version is also natural and may sound a little more conversational. In this sentence, 比べ is just a concise written connector.

Because 末に is part of a grammar pattern:

Vた + 末に
= after doing X and going through that process; in the end

So:

• 確認した末に = after checking, and after all that, finally...

The た form here is not just ordinary past tense in the English sense. It is the form needed to modify 末 in this grammar pattern.

Common examples:

• よく考えた末に、決めた。
• 話し合った末に、結論が出た。

末に has a stronger nuance than 後で.

• 後で / あとで = simply after
• 末に = after a process, after consideration, after effort, and finally

So 末に suggests that the speaker did not choose quickly. They compared things, checked details, and then made a final decision.

Compare:

• 確認した後で、クロスバイクを選んだ。
  = After checking, I chose a cross bike.
  Just sequence.

• 確認した末に、クロスバイクを選んだ。
  = After checking and going through that whole process, I ended up choosing a cross bike.
  More deliberate and final.

Because they are both the direct objects of their verbs:

• 変速機を比べる = compare the gear systems
• 変速段数を確認する = check the number of gears

So を marks the thing being acted on.

One thing English speakers often notice is that 比べる often feels like it should include both sides of the comparison, such as A and B. In Japanese, the other side can be omitted if it is obvious from context.

For example, this sentence implies something like:

• comparing the gear systems of the bikes being considered

You do not have to state both sides if the listener already understands what is being compared.

They refer to different things:

• 変速機 = the gear-changing mechanism / transmission / shifting system
• 変速段数 = the number of gear levels, such as 7-speed, 18-speed, 21-speed, etc.

So the sentence suggests two separate checks:

1. comparing the actual gear systems
2. checking how many gears each bike has

In Japanese, クロスバイク usually means a hybrid bike: a bicycle that mixes road-bike and mountain-bike characteristics.

So in many English-speaking markets, hybrid bike is often the most natural equivalent.

It does not usually mean something like a motocross bike here. In Japanese bicycle vocabulary, クロスバイク is a standard everyday term for that bicycle category.

The subject is omitted, which is very normal in Japanese.

English usually requires a subject like:

• I chose
• he chose
• she chose
• they chose

Japanese often leaves that unstated if the context makes it clear.

So クロスバイクを選んだ could mean:

• I chose a cross bike
• he/she chose a cross bike
• we chose a cross bike

Context tells you which one is meant.

Yes, but they are not as rigid as English punctuation.

In this sentence, the commas help separate the stages of the action:

• 変速機を比べ、
• 変速段数を確認した末に、
• クロスバイクを選んだ。

They make the sentence easier to read and show where one part ends and the next begins. Japanese commas often mark pauses, clause boundaries, or places where the writer wants to make the structure clearer.

Yes, it is natural, especially in written or explanatory Japanese.

It sounds like someone describing a decision-making process in a slightly neat, organized way. The use of 比べ and 末に gives it a somewhat more written and thoughtful tone.

A more conversational version might be something like:

変速機を比べて、変速段数も確認したうえで、クロスバイクを選んだ。

But your original sentence is perfectly understandable and natural. It just sounds a bit more concise and formal than casual speech.