When I sold bikes (managed/owned a shop) to parents for their kids, I told them to stay with one ring. We'd even block out the other ring/s when the bike was new, and when the kid started clamoring for more speed we'd unblock the ring (for free).

The biggest rule is shift one gear at a time. The biggest mistake novice riders make is using the lowest or highest gear and nothing in between.

14 years old, the kid is going to have some knowledge of how things work. You shouldn't necessarily dumb things down to a 5 year old's level, but worrying about technical stuff isn't going to help.

I always told people to check where the chain is. More left is lower gears ("left-lower"). More right is higher. If you want to go faster, use higher gears.

Also, although I have no idea who either of you are, if you're all kitted up and your son is even a normal level of self-conscious, it may be that he isn't really motivated to stay with you or he's embarrassed about the bike or something.

Finally, positive reinforcement. When I started learning chess my dad would do things like take away his own queen, bishops, etc and then play me. Or in Go (Japanese strategy game, described as "ruthless" compared to chess), where you have handicap stones (more than 1 or 2 is pretty significant, kind of like golf), he'd lay down 30-40 stones for me. Then we'd play. Eventually he'd play with all his chess pieces and I'd rate just a 4 or 5 stone handicap (my dad was ranked reasonably high in both games in Holland at the time - he was like a Cat 2 bike racer, maybe Cat 1). If you have a mountain bike or even a hybrid, use that when riding with him. Don't demoralize him by sprinting away. Emphasize the positive. "Excellent cadence". "You shifted perfectly as we got into that last climb." "You did great through that intersection, I could see you look at the car to make sure it stopped at its red light before you went through the green light."

Finally, although it may drive him away from the bike, find out what he likes to spend his time doing. If he's passionate about something in particular it may be easier to support that. When I was 14 I was an absolute bike geek - I had the exact opposite problem of your son, I was constantly fiddling with freewheel ratios and such. My parents weren't keen on it (I crashed now and then, roads are narrow, they had regular parental worry, etc), and my mom would have to defend my right to ride as my dad would forbid me from riding every time I crashed. They supported my passion and allowed me to develop it.

Good luck with your son. Even if he doesn't realize it now, he'll appreciate your efforts later.

cdr