HAVE A GRIPPING READ !
Basically there are two sizes of handlebar in the motorcycle world so, therefore, there are two sizes of grips to suit: 7/8" (22mm) or 1" (25mm) and PLEASE NOTE: The size refers to the diameter of the handlebar tubing NOT the grip.
To find out what size handlebar you have on your cherished and illustrious machine there is a complicated method of measuring round the outside of the tube and dividing the figure by your Grandma's pet Poodles' inside leg measurement etc. OR........ we have my simple method - remove the left hand grip and measure across the end of the tubing!
One other factor is the length of the grip - which tends to average around five(ish) inches long. I list the length of the grips I sell so just double check this against the old grips on your bike in case there is any major difference (the only ones I've tripped over so far is Gold Wings which seem to be six(ish) inches long).
NOTE: A pair of 7/8 grips (or a pair of 1") will have the same outside diameters but will be different inside diameters to suit the handlebar size on the LEFT or the twistgrip size on the RIGHT!
Removing the grip can be tricky, or as Haynes would put it - this is a simple procedure! For once, Haynes are right. Get one long thin screwdriver and one can of WD40 - squeeze the screwdriver blade up between the grip and the handlebar (from the switch block end) - spray some WD40 between the grip and the bar - remove the screwdriver - wiggle the grip to work the WD40 around - repeat as necessary. One application may do it, two or three certainly will.
Putting new grips on is a reversal of the above (sort of) - spray some WD40 up inside the new grip, work it around with your finger and push it onto the bar quickly (before the WD evaporates!). Job done.
This should be OK for normal road use but for heavy duty use you may want to put them on with some PVA glue or similar to make sure they don't slide off in the heat of battle!
HOPE THIS HELPS AND THANKS FOR YOUR INTEREST.
JOHN (ridleydiddly) RED SHIFT MOTORCYCLES