They can also raise fresh capital or adjust the premiums from other lines of business to subsidise their Motor portfolio.
Or they can simply stop insuring certain lines of business or charge more for it.
It is obvious that Bike insurance isn't the flavour of the month at present and loss ratio's are increasing - so premium hike are reality
Possibly down to high theft ratios, certainly of GS and other Adv bikes
So it has been expected for a while, can't see why people are moaning really - it wasn't as if you couldn't forsee the train down the tracks