The specialist comment makes sense, and I really hope I never need to claim, but as a point of reference - at 40 and with 2 yrs NCB due to ownership breaks, no adverse factors, I paid £330 for combined annual cover on a Pan European and a TDM, both fully comp and with my foreign trip on the Pan included (which cost £21 - all related to Romania, Bulgaria and Turkey as standard EU and the closer ones come free). That includes full European breakdown plus medical/legal, which seems reasonable to me. Amusingly, the excess when riding the Pan is £250 - 2.5x the TDM. Which makes no sense - The Pan is more likely to get dropped, and would be more expensive if I did..... they must put a lot of faith in those engine bars !

Insurance companies can be funny sometimes. Chances are that their experience is that they get fewer claims from ST1100's - hence the lower rate.

I traded in a VW Golf on a VW Phaeton last fall - my insurance cost actually went DOWN when I got the Phaeton, even though it is about 4 times the price of a Golf. I asked the insurance company why, and they told me that they experience very few claims from drivers of that type of vehicle (Phaeton) - but get tons of claims (theft, accidents, etc.) from Golf drivers. Maybe that's the case with your two motos - they are looking at fleet averages.

Michael