Hey Keith, My 865 came with a 16 tooth front. I ran it a few years, then switched to a 17 tooth when replaced the chain/sprockets a few years ago, and it's been ok. But I will be going back to a 16 this year when it's time to replace them again. I don't think I would like the 18 tooth on this bike at all, although some do. I say go with the 16 and you'll be happy with it.
Take it easy,
Will
