That's what I wanted to say to this guy on the Slickrock Trail, out in Moab, one day.
We were in Moab for a few days back in 1996 or 1997, doing a club trip, and I was riding with 3 or 4 other guys I knew. We had already ridden a couple of trails, and decided to do a quick trip around the Slickrock Trail, before calling it a day. As we approached the turn which would take us from the Practice Loop to the main trail, we saw a guy walking his bike across the rock, toward the parking lot.
"Flat tire?" I asked, as we met. It's amazing how many people go completely unprepared, and i always feel obligated to offer help.
"No, my front brake is broken," he replied. "I can't ride this trail with just a rear brake, so I'm headed back to the car."
I asked him if he minded me looking at it, and explained that I was a bike shop mechanic; I might be able to fix it.
I took a quick look at his front brake. It wasn't "broken", but he had lost the mounting bolt for one cantilever arm (remember, mid to late '90s, not many v-brakes were on the trail yet, much less disc brakes like we have now), so the arm was just hanging from the cable.
"I can fix that, if you want to keep riding."
"What," he said, looking skeptical, "do you carry brake bolts with you?"
"No," I said, "but you do."
I pulled out my Cool Tool, and removed the 5mm clamp bolt from one Onza bar-end extension on his bike, and used that bolt (which is exactly the same bolt that holds canti arms on the stud) to remount the brake. Thirty or forty seconds of work, and the guy was back on his bike.
"Now you can ride the trail," I said, as I hooked the brakes up.
He gave a look, as if he was kinda disgusted with the whole situation. He told me that he had been pushing his bike for over 3 miles, and that he was just going to ride back to the parking lot and take his car to town.
As he rode off, I couldn't help but marvel at how people see bikes and bike parts as units. He had never thought to just pull a bolt from a non-vital part in order to repair a vital system. A little imagination and logic will go a long way, when you find yourself stranded by the side of the trail.
Just stop and think, for a minute; It might save you a lot of walking.