yeah I think so too. Those high precision outdrives plastic is too smooth (like nylon) and the rings have nothing to grab onto. The old TA05 had "D" rings that fit nicely into those outdrives.
The 416 has uses round rings, but have no issue of slippage since it is on metal to metal.
Also, maybe it's just me... there is supposed to be a 2mm washer for the front suspension spacers but I got 1mm ones instead.
Other things of notice:
1. You need to shave parts of the chassis where the belt might rub. Guess it was not designed to take anything over 36T pulley. No problem once you shave it.
2. There are four screws holding down the center shaft. If you tighten all four, it causes binding on the bearings. I took out the front two and the bind went away with no slop. Still need to test it out like that.