Originally Posted by
sweeks
Certainly any visible defect in a welded area is cause for concern. The history of that particular frame is not given, so it's hard to say whether its defect is structurally significant. If it's a brand new bike, then the crack is more worrisome. If it's got a few thousand miles on it, not so much, as the crack has not propagated since it was painted.
I certainly would not have accepted delivery of a frame like that. But I'm happy with my VS11i (no need to pity me! I'm pretty vigilant on frame inspection even with the new design) and am looking forward to Tern's reputation getting back up to where I think it should be. There is a fairly steep climb on that issue at present, I am afraid.
FWIW, I've had two Dahons break on my watch, so I'm well aware of the fine line between lightness and durability in aluminum frames.
When I had a second look at that image I assumed that initially the whole crack was painted but with use and the fatigue of riding it started getting worse/larger from the bottom upwards. If you ride a bike and the frame fails it will likely want to bend or break upwards in a U or V shape. The crack on that frame is gradually increasing in size from the bottom upwards. To me that is crack working towards failure which was luckily caught before a possibly life threatening frame failure.
Thats the case I've always made that Tern and most of the Dahon's are performance folders with lightness and speed part of their appeal but with a shorter frame life just as you would expect from a performance full size road bike. It's clear there are strong Dahon's though with their original models and the new Curl but I don't actually know of any strong Tern models even if they were made to a consistent high quality. At best you are going to get a weaker than average frame only capable of the stated maximum rider weight and at worst pretty much destined to fail whatever the rider weight. It's the bike version of this.
