Joined: Jan 2006
Posts: 634
Likes: 3
From: Central WI
Bikes: Raleigh Olympian, Trek 400, 500, 1500, 6700, Madone 6.9, Sekai 2400, Schwinn Passage, KOM, Super Letour, Nishiki Sport, Vision R45, Bike E, Volae Team
One other possibility is an out of specification chain. Unles you accurately measure the chain before use, you cannot be sure it was wear. It may have been "too long" when manufacured. The variation you described earlier in your measurements suggests there may have been a problem.