>>1982652I've never had someone steal a pannier or handlebar bag, but twice I've had someone take a framebag. It's so dumb, because I make one for each of my bikes, so it's custom-fit to that frame.
There wasn't anything truly valuable in either... Topeak pump, multitool, etc. The most annoying thing was losing my favorite pocket knife.
What I started doing after #2 was using an two bits of old brake cable to secure the bag at two points. One around the seat tube, one around the head tube, each loop as small as possible. Two because it's much harder to "build up speed" when trying to pull on the bag, can't really get a strong jerk motion.
For each loop, I'll put a pair of grommets in the bag, run the cable around the tube, through the grommets, and secure the ends using two of these little aluminum things. The smallest ones from Home Depot work well with brake cable. I pinch the shit out of the fittings with a big Knipex pliers wrench.
All of that is under a velcro strap, so it's not normally visible, and water doesn't get in the grommet holes. It's the best I could come up with for a retrofit solution.
But it's not truly secure--anyone with a pair of pliers could probably dismantle this. It only prevents opportunity theft. But at the same time, I haven't had a bag stolen since 2017.
I very rarely take the bags off once I make them (once every two or three years?), but it's simple enough to snip the things off and install new loops.
