Originally Posted by Rammer
I presume it's a bad idea to modify the forks of a bike with a drill to make a screw hole for say front racks? Seems it would affect the structural integrity. Are forks with mount holes made of thicker tube than those without?
What about modifying the down tube to add more spots for water bottle cages?
The thickness of the tubing, and the tubing material itself would be important factors.
Also, rider weight and type of riding.
If the bike is barely strong enough to begin with, drilling holes is probably a bad idea.
If it is overbuilt, and there are margins to spare, I don't think there would be a problem.
EXCEPT: holes can create stress raisers. (It is probably a good idea to talk with a good frame builder who understands these things well.)