Ergon do 2 variants of each of their grips.
One variant is left-side & right-side symetric
The other is asymetric with, typically the righ-hand-side, shorter to accommodate grip-shifters (Rohloff and Shimano Nexus and Shimano Alfine)
Thorn typically chose the symetric, but then saw/cut off some of whichever grip has the grip-shifter next to it.
It is perfectly possible to further trim the shortened grip.
In fact I find that Thorn trims a symetric grip less than the amount that Ergon shorten their asymetric grips.
I have Shimano XTR 2-finger v-brake brake levers which, for me at least, work very well with the Rohloff shift mechanism.
I initially did not get along with the GP1 grips, so I tried a set of (asymetric) GP5 grips.
But I did not like these either so I went back to the Thorn-trimmed GP1 grips but with the addition of some Cane Creek bar-ends.
I could probably a photo if this would help?
