Remember that one grip will have a smaller inside diameter than the other. The larger one goes on the throttle.
I once spent ages trying to force the small i/d one onto my throttle side. Got it on eventually, then found the left one was like a stick in a bucket! Doh!
Ha Ha Ha I trashed a grip on the DD bike, fiitted new throttle assembly yesterday, got one new Renthal grip out of the box, spent half an hour trying to fit it over the throttle assembly using first hairspray and then WD40, too tight, gave up. Now I realise why! As you say, obvious really!!!
If this is your track bike I guess it'll be apart a few times. Fit 'em dry or just with water as lube (as someone said prev') that way, you'll be able to get 'em off again with only the minimum of swearing and sweating!
Update - Throttle side went on a doddle..and is nice and snug
l/h side is a RIGHT BIATCH !!!! Tried brake cleaner - warming tem up etc, they are now 3/4 of the way on and ive lost all the feeling in my hands from all the twisting !!
Round 2 tommorrow I guess ! Compressed air sounds like a great idea but I havent got such luxuries unfortunatley.. :>(