My LV= insurance was good for bikes under £300 (might have been £250) and paid out very promptly They were included automatically in the home insurance (and didn't do "pro rata" as dh's bike, with the extra bits n piece, was worth more). Excess was only £50.
However, when I went to add all our bikes (including ds' excessively expensive ones), so that they we're insure closer to their true value, the additional premium was extortionate .
When my buildings & contents renewal came up for renewal, I shopped around and found a combined policy that covered the bikes as well as the house and contents for about the same "extra" that LV= wanted to charge just to include the bikes. (Was OneCall, underwritten by AXA)