、。
She can ride a bike, of course, and a motorcycle too.
Literal
She [topic-は] bicycle [contrast-は] [needless-to-say-もちろんのこと], motorcycle [also-にも] can-ride.
~はもちろんのこと is a tidy comparative construction meaning 'X goes without saying, but Y too' — frames X as the obvious baseline and Y as the surprising extension. もちろん ('of course') is the lexical core; のこと is a softening nominalizer. The で here on the second clause is にも — に (target/goal of 乗る) plus も (additive 'also'). Japanese 乗る takes に, not を: you 'ride into' a vehicle rather than 'ride' it. オートバイ is a homegrown wasei-eigo coinage from English 'auto' + 'bike' — the actual English word would be 'motorcycle,' but Japanese cobbled together its own version.