Hi mate.....
Not sure if it clarifies anything, but last year I started my own company and changed a few of my policies around, pension etc. My Financial Advisor talked to me about life cover, critical illness and whilst we were on the subject I mentioned motorbikes, both riding, trackdays, trips to and from places (both europe and uk) and she went a bit white. Said there had been a few issues with cover for motorbikes and other "extreme" pastimes. (I know I know...but let me finish).
Anyway, she had to get specific paperwork from the company (Norwich Union & AXA) for me to detail my activities on my bike. Usage, experience etc and send it off. Now I never found out if it specifically affected my premium but at least I know I'm covered should I die or be injured and out of work due to my injuries.
Now, with bearing in mind the above (but please don't take this verbatim as it could be company specific) it would infer that if you were to hurt/die in direct relation to riding your bike, if was not declared at point of inception then you may be buggered.
Either way...everyone is right. Ring them and check, and if not get it written into your policy. If it ups your premiums, surely got to be worth it in the long run. Unfortunately it would appear, similar to the insurance claim industry and inherent blaim culture towards bikers, that the life policy and criticial illness markets are still persecuting us bikers.
(Hey Hammy...short answer as always
)