I want to build a rack on the back of my bicycle that will be strong enough to hold my girlfriend. The rack will be similar to the configuration of an Xtracycle's rack i.e. with a horizontal and vertical portion that would look like an L to either side from the rear. The current design would subject one of the rack members to a maximum foreseeable compressive force around 135 lbs (in her defense, my girlfriend is only 130 lbs, but the rack is designed to be multipurpose).
Is there any reason to be concerned that the dropout rack braze-on may fail? The bike is an older steel MTB with two rear rack braze-ons on the dropouts. I intend to try connecting the suspect member to both braze-ons.