The TwinPegs are designed and precisely manufactured to be bolt on, with a tight fit, and fewest possible parts. However, due to production tolerances of the ears for fastening the original footpegs to the motorcycle, I have on some bikes experienced the need to adjust the shape of the machined groove in the stainless torque transfer piece slightly with a flat file. Pre install the piece, and check with the black bolt whether the holes line up. The black bolt is only meant as an installation tool, to prevent damage to the stainless bolts, when testing that the bolt can be installed. Adjust both sides of the groove, so the straight sides of the piece keep an orientation parallel to the bike. No modifications is to be done to the bike.
An example where the groove sides needed to be adjusted quite a bit.
Some craftsmanship is required when adjusting the groove sides. Hand work, no need for a machine shop. Remove a little material at a time, test fitment frequently. Patience pays off, giving a tight fit for a long time. Tighten the bolt that replaces the original bolt through the front footpeg, original or aftermarket.