How wide are the grips? I have one of these:
Shop Zefal 95293 Spy Double Adjustment Bike Mirror for Road and MTB. Free delivery and returns on all eligible orders.
www.amazon.co.uk
They would be able to go around quite a wide grip. However, I don't know if I got a dud or not. It is OK but not great, it is discreet (it can be under the handlebar) and in exactly the right position it gives quite a wide view of behind. However, it tends to move about and the optical quality is not great. On my normal bike I have a differnet one that goes into the end of the handlebar, it sticks out a bit, but it is easy to adjust, says in place for quite a long time, and has better optics.