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hairline crack in lug - should I panic ?(5 posts)

hairline crack in lug - should I panic ?dotkaye
Jun 5, 2001 12:07 PM
I have a Japanese steel frame, Tange tubing. Washing it on Sun after a wet morning's ride, I noticed there is a hairline crack about 1/4" long, in the lug that joins the seat tube to the bottom bracket. It's on the upper edge of the lug, not quite between the lug and the tube. I was hoping to keep this bike for another few years, but maybe it's time.. opinions ?
tia.
retire itpeloton
Jun 5, 2001 12:38 PM
Anytime that there may be structural damage to a frame like you describe it is time for retirement of said frame. Where the seat tube meets the bottom bracket is a high stress area that gets a lot of torque from the pedals. There is a chance that this crack could develop into something much worse from this torque, possibly even a complete failure of the lug. I wouldn't take the chance in trying to get more time out of the frame. IMHO
you sure it's not the paint?Hank
Jun 5, 2001 1:02 PM
you sure it's not just a crack in the paint? Might take it to a good shop or framebuilder for an opinion. Otherwise, I'd just watch it closely and perhaps start shopping around for a new bike. It's never a bad idea to have 2+ bikes, anyway. But I doubt you'd have some sort of major failure - bars, stems and forks are much more of a problem if they break. I had a friend who broke his downtube and all he noticed was that the bike suddenly got a bit more comfortable, but handled somewhat strangely (apparently, this is how the Slingshot bikes were invented).

http://www.slingshotbikes.com/framedesign/suspension.htm
It is worth removing the paint to see ...Humma Hah
Jun 5, 2001 7:11 PM
... none of the inspection methods, be it dye penetrant, magneflux, etc, will work until the paint is removed. I can usually spot a crack by eye, with a little magnification, but I had about 15 years in the business.

If the part is powdercoated instead of painted, my bet would be there's either a crack there or one will soon appear. Powdercoat bonds so well that every time I've ever seen a crack develop in it in tests, the part soon fails.
turns out the answer is yes..dotkaye
Jun 6, 2001 10:51 AM
after hearing untoward noises on today's ride, the crack is now an inch longer, and extends deep into the lug itself. Hum. Anyone have a nice (cheap) 59cm frame for sale ?
Meantime I guess it's back to the Schwinn Continental luxury ride for me..