Four people have been arrested.
The 58-year-old was struck by a Seat Leon between the junctions of Muntz Street and Charles Road at around 11pm yesterday.
The car briefly stopped at the scene before it was driven away.
A short time later, three boys aged 17 and a man aged 19, arrived at a Birmingham police station where they were arrested on suspicion of causing serious injury by dangerous driving.
The victim remains in hospital in a critical condition today.
Det Sgt Paul Hughes, from the Serious Collision Investigation Unit, said: “Our investigation is making good progress and we’ve already spoken to several witnesses, but I’d urge anyone with dash cam, helmet cam, or CCTV footage, to get in touch.
Get in touch via 101 or Live Chat quoting log 5374.
