Is it a fixie or SS?
If it's being used as a fixed gear bike you're putting added stress on the frame every time you use back pedaling to slow down or stop.
On a frame that size and as high as the seatpost is raised all of the forces going into the saddle are being concentrated in the area of the CRACK!
NO IT'S NOT IN THE PAINT!!!
The bottom of the seatpost rests in the area of the crack. Seatposts should be inserted 75mm to 80mm (~3") into the seat tube.
JohnDThompson "I suspect overheating the seat tube while brazing."
Easy to do while creating a fillet when attaching the seat stays....
If it were a 55-57cm frame and the seatpost were inserted 4"+ and I weighed under 150 Lbs. I would ride it and watch the crack carefully. I'd put a mark with a SHARPEE pen at both ends, keeping an eye on the lug point too.
For example: BB on a 753 frame... Is it a crack or a brazing flaw??? I carefully inspected it inside and out and a local frame builder did too. He thought that it was in the brazing.... That was about 10 years ago.
verktyg
