Just converted my hard tail to 1x9. I've removed the granny and big ring, put a chain guide on and put an 11-34 cassette on the back. Runs so quiet and simplifies the cockpit a little. Just been riding to work on the flat flat flat Beijing roads. The real test comes this Sunday when I hit the mountains for the first time this year. Will I miss the granny. Probably but I can always walk!