Cycling insurance

Never really considered cycling insurance until I’ve purchased quite an expensive bike, suppose it makes sense. I’m not commuting to work and cycle on very quiet roads, and participate in some races. Not sure who to try, my frame is the most expensive component I’m most concerned about, how does it work when it’s not a complete bike I purchased as such but a frame then added more expensive wheels etc?

I regularly use my GOPRO just in case I’m involved in an incident that’s not my fault and I can’t prove it otherwise.