The end of BM original bars is threaded to take their own bar end weights, which are cut to accept the handguard. People have got round this problem by using oversized rawlplugs when fitting onto the Fatbars.
I used a short length of hose pipe as a rawlplug, which just about worked, but because one of the guards was bent from impact it was all a bit skewed. Plus the bars start to fatten up at the point where the other end of the guard clamps on, which made things awkward with clamps designed for the original bars.
I was hours away from a big trip while I was wrestling with all this, so I just ditched the guards. Not a problem when the temperature is 38C, but I'm feeling the difference now on the frosty mornings.
Just realised the Storm is single point fitting so offers no crash protection. I'll stick with the VPS model.