The 8-speed chain is too wide for 9 speed front derailleur; the chain will rub during cross shifting (large/mid ring/large cog).是什麼意思_The 8-speed chain is too wide for 9 speed front derailleur; the chain will rub during cross shifting (large/mid ring/large cog).在線翻譯_英語_讀音_用法_例句