Got myself one of
these when I changed the chain and sprockets last time.
Also needed an impact driver socket to fit on the sprocket nut, a few pounds from Halfords.
I have an old car battery in the garage that will not start the car but gives enough power for this.
It's my new favourite power tool.
Used it to remove the flywheel on the Morini for cam belt changes and it laughs at the wheel nuts on the campervan.
Steve