Angry that there's only one speed (5)
I believe the answer is:
irate
'angry that there's only' is the definition.
'irate' can be an answer for 'angry' (I've seen this before). I'm unsure of the rest of the definition.
'one speed' is the wordplay.
'one' becomes 'I' (Roman numeral).
'speed' becomes 'rate' (the speed at which something happens).
'i'+'rate'='IRATE'
Can you help me to learn more?
(Other definitions for irate that I've seen before include "Annoyed, nettled" , "Ticked off" , "Fuming" , "having got in wax" , "Mad" .)