Uh-oh, Motobecane Jury frame failure! (Do all TIG welded frames fail?)

Close up of the crack in the weld and tubes.

 I had an unpleasant suprise recently when I was working on My Jury commute bike. I had replaced the fenders because the rear stainless steel one had broken off at the brake bridge. After installing new fenders and reconnecting the tail light wiring I discovered a small line across the weld of the bottom bracket(above). Pushing down on the crankarm expanded the line! I got a cracked frame at the bottom bracket (hereafter refered to as the BB)!

An uncropped view to show the extent of downtube crack.

 In the picture above, you can see how the hairline crack traveled from the back of the BB and along the downtube, then it curves downward.

Another close up.

This final shot shows the crack at the BB again. The weird thing about this is that it is almost identical to the failure I had with my Surly Steamroller about 3 years ago! The failure was again at the BB and it also took an almost identical track across and then down the downtube!

I wonder if this is a common problem with fixed gear, TIG welded bikes? Or is it that the Surly and Motobecane are just too cheaply made to be good fixed gear platforms? I'm not really hard on my bikes, I'm 57 years old, weigh 175 lbs, and both of these bikes were used soley for a relatively flat commute of 26 miles a day, (round trip), but I don't ride every single work day. So, I really don't think I'm putting an unusual amount of stress on these frames. Now, I realize that the Jury is a bargain basement frame, so it is no huge shock that it failed after 3 years of use, but I thought the Surly was a better quality frame, maybe not...

I'd be interested to hear from anyone regarding this type of failure on a TIG frame, please feel free to comment!

On the plus side, this has given me the chance to shop for a new frame! I had to be thrifty though, so no exotic lugged steel custom job right now. I went bargain hunting, since my commute to work will only continue for about 7 more months, (then retirement!)!  I'm going with another welded frame, but this time something completely different. I found a Performance Bikes "Ascent" aluminum single speed road frame on sale for $89, then another 20% of for a Black Friday sales event! I also found a nice Chrome-moly fork from Nashbar to go with it.

I have never owned an aluminum road bike before, so this will be a fun experiment, and if it does crap out, it will be interesting to see if it does so faster than the TIG welded steel!