I have a quick question for you guys. I want to buy a KMC X10SL chain for my bike as the other one is worn. I notice some come in 112 links, some 110 and others in 116. How do I know which one to buy? I have a Madone 5.2 bike with 53/39 and 11/28 cassette. I don't to buy one that is too short so I thought I should ask before I buy off of ebay and make a mistake.