West Midlands Police is appealing for witnesses after the collision on Thursday, October 7 involving a VW Polo and a motorbike at the junction of Catherine De Barnes Lane and Shadowbrook Lane.
They are particularly keen to hear from the occupants of a car travelling directly behind the Polo who will have seen what happened
It happened at around 5.30pm and the rider of the Zero SPZ electric motorbike remains in hospital with serious fractures.
The driver of the Polo remained at the scene and is assisting with the police investigation.
Detective Sergeant Paul Hughes, from our serious collision investigation unit, said: "We are told by witnesses that a red Vauxhall Astra, possibly a 64 plate, was behind the VW Polo at the time of the collision. I believe the occupants of that car may hold key information that is relevant to our enquiry.
“I must emphasise that I consider those occupants to be witnesses in this case and I would urge them, and any other witnesses who haven’t spoken to us to come forward. You can help us get the much needed answers for everyone involved.”
Get in touch with the police by calling 101 or via Live Chat on the West Midlands Police website and quote log 3146 of October 7.