请帮忙分析一个英语句子的结构----高手帮忙

请帮忙分析一个英语句子的结构----高手帮忙
It is not because the bicycles are expensive or people feel tired if they ride to work.
It’s because the number of cars on the roads becomes more dangerous to ride a bicycle.
只要分析第一句,第二句是给你们参考的.总觉得第一句意思的翻译不是很通顺.
关键是if的翻译，我看到你们好像多没翻译if的意思。请重点解释if

句子意思:这不是因为自行车贵或人们骑车上班感到累,而是因为路上车子的数量使骑自行车变得更危险.句子结构：It 是主语,is 是表语,because the bicycles are expensive or people feel tired if they ride to work属于表语从句,表语从句中含有两个并列句,由or连接,if they ride to work是people feel tired 的条件状语从句