Best bet for insurance is to contact the country-specific organisations, such as the BIPP or AOP in the UK, or FreeLens in Germany,... Don't have to dig too deep – most local photography magazines have contact details or adverts.
I'm from Germany and found an insurance broker through FreeLens (one of the German organisations for photo-journalists). I pay 3% of my gear's value each year. This includes rental equipment and my laptop. Everything is insured even inside a vehicle, during daytime.
If anything gets stolen from the vehicle at night, I would have to prove that I was doing a comissioned job (i.e. a concert or wedding,...) and get a statement from the comissioner. Then the gear would be insured any time of the evening/night.
Now: I don't know what the deal is for motorcycle travelling. But since I have been with them for 3 years and never had any claims, I will try to negotiate something with them for longer motorcycle trips.
I don't know if they do insurances for non-German residents. But, by all means, give it a go: "HTV Versicherungsmakler GmbH" in Hamburg; Telephone 0049 40 80806580