i get my chains from pirates, they are a 415 chain but smaller and lighter! with the 41 chain, and the other 415 chain ive ran before, theyre too big and heavy, causing lots of vibration even with the tensioner. the chains are 15 bucks and youll need 2 of them if one isnt long enough, then go to your local bike shop and get a chain breaker. this will help you get your chain to the exact length you need, without using a master link. If you do use a master link however, one is enough, they make a weak spot in the chain and with the right chain breaker you can put your chain together without it... hope that helps.