It helps to drive one round the bend (8,5)
I believe the answer is:
steering wheel
'it helps' is the definition.
The definition suggests a singular noun which matches the answer.
'drive one round the bend' is the wordplay.
I cannot really understand how this works, but
'drive' could be 'steer' (I've seen this before) and 'steer' is located in the answer.
'one' could be 'i' (Roman numeral) and 'i' is found in the answer.
This explanation may well be incorrect...
'to' is the link.
Can you help me to learn more?
(Other definitions for steering wheel that I've seen before include "Car control" , "it changes direction" , "part of car interior" , "Means to turn" .)