I’ve got the bikes insured seperately, because whilst it is potentially/almost definitely more expensive, I am sure I have much better cover than otherwise possible – it covers events, damage while racing, legal cover and injury, new for old, being stolen during transport or out the back of the car etc etc, and the value is quite high, nearly 10k all in with the fancy one being 6k.
Yes, its a lot of money but my bikes are by a long long way the thing I worry about most, much more so than my cars.
None of the household insurers gave me the confidence that that would actually cover the bikes – for instance – if they get nicked from the car or van, your car insurers will doubtlessly have a (low) limit on the value of stolen possessions, and your home insurers will say “thats your car insurers problem”.
It also means i can freely purchase much simpler and cheaper home and contents insurance as there is nothing unusual otherwie to worry about, and the bikes are the only expensive thing owned.
Having them added to your contents cover may work for you, but check the cover and wording carefully…