I've got a question on adjusting the chain tension on my bike. Swingarm sticker says 61mm-63mm. Mine measures like 65mm after about 2K miles. I know that it's better to have a chain too loose than too tight. So is the 2mm I'm over the 63mm "worth" doing an adjustment? I'm just wondering what the tolerance is, or is the 61mm-63mm the "real" range?