Thames Valley Police is appealing for witnesses following an assault near Datchet.
At 2.35pm on Sunday 31 May, two cyclists were travelling south bound on the B3021 Southlea Road from Datchet to Windsor.
A person in a white pick-up truck, travelling in the opposite direction towards Datchet, threw a drinks bottle which hit the first cyclist in the chest.
The victim received bruising and inflammation to his chest, he did not require hospital treatment.
Investigating officer PC Alexander Massey from the Windsor and Maidenhead Smarter Resolution Team, said: “This was a frightening experience for the two cyclists, and I am appealing to anyone who has any information about this incident to come forward.
“If you were driving or cycling in the area at the time and saw anything, please get in touch.
“You can contact us using the online reporting form, quoting reference number 43200160762. If you cannot report online, call the 24 hour non-emergency number 101.
“Alternatively, you can call Crimestoppers 100% anonymously on 0800 555 111.”