It's like those awful-looking spoke protectors - shouldn't be necessary if you know how to adjust a derailleur's limit screw.
Adding components to make up for lack of mechanical competence seems to be approaching the problem arse-backwards, IMO...
BTW, I deliberately tore out one of those pins once, as it offended me.
Last edited by Kimmo; 12-28-09 at 07:05 PM.