RoJ, if you can dismantle it enough to get access to the bearings, you'll probably find that they are bog standard ones, readily and cheaply available. I managed to replace the bearings on an older set of Tacx rollers. HTH
Thanks for all your thoughts so far. I've just been reading some very positive reviews of rollers on Wiggle. It would appear that they are loads more enjoyable than resistance trainers and still provide a good workout. What does the panel think ?