Hi guys I'm looking to change the rear sproket on my KN150 from the standard 43 tooth to 39 tooth, and I'm wondering if I need to remove some links from the chain? I've been told it's not necessary, but isn't it going to leave some slack in the chain? Or is the slack taken up by adjusting the rear wheel location? Also, if i do remove links, is it as straight forward as 43-39=4 so remove 4 links? Thanks in advance.