KennyB has called it right. No big deal....as long as you've got the right bits. Not having played with this type of head tube setup before, it took a while to realise that the large lower bearing doesn't actually fit snugly on the steerer tube, but requires a collar below to hold it in...
All now sorted....resolved by the guys at l.b.s. (G&B Cycles(y)(y) in a soggy Northwich). Reducer plate required replacing with similar, but to fit Rockshox's larger steer base.
Thanks
Just in the process of changing the stock Suntour forks (which have a 1 1/8" steerer and a reducer fitted) for a set of Rockshox 35 (which has a proper tapered steerer - 1 1/8" to 1 1/2"). However, using the original bearings (only 2 months old), I can't get the headset play right; either too...