Hey Joe...I just put together a mountain bike and I'm having trouble with the chain. First test ride I went about 50 yards and the chain suddenly got very tight. I adjusted the tensioner. Second test ride ...same thing happened. I thought it would, if anything, get lose not tight. I adjust the slack roll a little and it tightens up.. It don't figure! In fact the third time it came off! What am I doing wrong. Thanks for any suggestions