Dogtag for me, they’re not the cheapest but they are at least very clear on what activities they cover – you can get generic “cycling” or “mountain biking” on a lot of mainstream policies and I’ve used them when I’ve been going on a family holiday with a bit of the old VTT included. I’ve read through endless lines of T’s and C’s and exclusions seem to centre around racing or riding professionally neither applies to me – but i’d hate to have to argue the toss with a bill for a Helicopter rescue or broken back – I’ve seen others with both on riding holidays.
I’ve claimed once, I had to cancel a trip irronically because I crashed at home a week before, it was a bit faffy, I had to prove I was unfit to travel, not just unfit to ride – but I was still in hospital throughout the entire time I was meant to be away so pretty open and closed.