Is there a way to modify a throttle by wire grip to work on a street bob. There are some grips I want but they only come throttle by wire

 

Can't give you an honest answer when we really don't know exactly what grips you're asking about. There's around 300 different TBW grips from 50 different manufacturers.

 

Avon costom contour grips. Their version of the harley get a grip magnum grip. Avon has it in orange but only for throttle by wire. I was thinking if I used a throttle sleeve and chopped off the part that slips into the switch housing and also drilled out the part inside that engages the throttle sensor turn that it might fit