My extremely optimistic aim is to shed on average 0.5kg/week.
That's a perfectly reasonable, and sensible, weight loss goal.
3500 kcals a week deficit, or 500kcals a day, or an hour's hard cycling a day. Just don't over-reward yourself for cycling.
My motivation for weight loss is twofold:
1) Vanity. I want to look better in nice clothes (of course Lycra is especially unforgiving)
I fully expect my application to be a Rapha model would meet with "
Come back when you're not quite so fat"
2) Cycling. Nothing I've yet found makes hills easier than a lack of bodyweight.