Oddly I have to have a rider for my engagement and wedding rings (value approx $5k) but not the bikes (value of $10k combined). We have pictures, receipts and SN on all the bikes. Except my Craigslist Mountain Bike where I have SN and pictures.

I asked my agent specifically would it cover these high end bikes and told him I we paid about $2,000 EACH for the bikes. This is Texas where people spend a ton on guns, bows (my friend has a $1,800 one) and who know what else my agent didn't even bat an eye. It covers replacement cost minus deductible. I think it varies by state and even company. Talk to your agent and be very specific on what you are asking.