The O-ring chain is about 0.05" wider (length of pins) on my non-A65 bike compared with the non-O-ring version. This level of difference should not be significant in terms of whether a O-ring chain will fit on a A65. That said, you can pay twice as much for an O-ring chain and they are only really needed for bikes that will be used off-road. Even on my off-road bike, they are probably overkill!