This question is mainly aimed at engineers and frame builders.
The downtube on my frame cracked where it connects to the head tube, and eventually the down tube broke free (I was waiting to crash replace the frame so I didn't stop riding it). I recently just noticed that there are big cracks coming from the "vent holes" that are drilled in the head tube. Two large cracks come from the center of either side of the lower vent hole. Could the fact that the frame broke be a result of vent holes that were too large?
An Easton guide on frame building says: "Also, extra large holes can weaken overall strength of the joint, especially at the connection of the head tube to down tube. Use extra care to center large vent holes with the tube."
The downtube on my frame cracked where it connects to the head tube, and eventually the down tube broke free (I was waiting to crash replace the frame so I didn't stop riding it). I recently just noticed that there are big cracks coming from the "vent holes" that are drilled in the head tube. Two large cracks come from the center of either side of the lower vent hole. Could the fact that the frame broke be a result of vent holes that were too large?
An Easton guide on frame building says: "Also, extra large holes can weaken overall strength of the joint, especially at the connection of the head tube to down tube. Use extra care to center large vent holes with the tube."