So stiff you can't slide anything between them and the bar? I've found pushing a lolly stick or wooden skewer between the bar and the grip breaks the bond between the two making it much easier to then twist them off. It has the benefit of not getting any slippery liquids on the external surface of the grip itself, as that makes it a billion times harder to work with.
Not sure but to me they look very old school in their construction, ie, virtually no flex compared to modern grips, they would likely eat a lolly stick.
So stiff you can't slide anything between them and the bar? I've found pushing a lolly stick or wooden skewer between the bar and the grip breaks the bond between the two making it much easier to then twist them off. It has the benefit of not getting any slippery liquids on the external surface of the grip itself, as that makes it a billion times harder to work with.
For future ref, obvs.