Analyzing 「だけど勝つのはいつも金太郎で、大きな体のクマでも金太郎にはかてません」

Question

From the tale 金太郎【きんたろう】:

だけど勝つ【かつ】のはいつも金太郎で、大きな【おおきな】体のクマでも金太郎にはかてません。

I understand a few things:

1. だけど is contrasting the previous sentence.
2. の is nominalizing かつ.
3. The second 金太郎 takes the particle に because of the verb かてません.

I'm having trouble finding (1) the main topic, and (2) the subordinate clause.

I also don't understand how the other particles and the conjunction of this sentence are being used.

Answer 1

There's no subordinate clause here. That's coordinate clauses: だけどかつのはいつも金太郎だ・です and おおきな体のくまさんでも金太郎にはかてません。で in 金太郎で is the continuative form of the auxiliary だ.

The topic in だけどかつのはいつも金太郎だ is かつの, "the one who wins", and the subject in おおきな体のくまさんでも金太郎にはかてません is おおきな体のくまさん. でも, "even", has replaced the subject marker が.

Answer 2

だけど勝｛か｝つのは何時｛いつ｝も金太郎で大｛おお｝きな体{からだ｝の熊｛くま｝さんでも金太郎には勝｛か｝てません

So let's start from the beginning:

• だけど introduces a contrast with the previous sentence similar to but or although.
• 勝つのは nominalizes 勝つ and introduces it as the subject using particle は, thus the one who wins is
• 何時も adverb meaning always
• 金太郎で: This is the part stating that it's Kintarô who wins. で is the continous form (連用形) of the copula だ, here indicating that the sentence isn't over yet.
• 大きな体の熊さん: "Mr." Bear's big body
• でも is not the conjunction でも=but, yet, still, but the adverbial particle (副助詞) でも=even. See these questions for more details: 1, 2, 3 If it helps, think of it as 熊 で+(あって)+も, even if it is a bear
• 勝てません is the potential negative form (=cannot) of 勝つ.

So I would conclude by saying:

Although (something), the one who victory is always Kintarô, (and) even Mr. Bear with his huge body cannot win against Kintarō.

Or a bit further from the Japanese:

But Kintarô would always win, even the Bear with his huge strength was no match for him.