Congratulations for supporting the boy in an interest that he can enjoy for life. Some kids just seem to take to cycling and get a lot out of it.

May I suggest magazines as a supplement to what your son can learn here? If you have a good magazine stand nearby, with a few different bicycle mags, he can leaf through and refine his choices, and at his age he'll no doubt absorb knowledge like a sponge. A trip to the library for a look at their cycling books might be of some use. As a side benefit, his reading ability will probably increase dramatically as he feeds his curiosity about bikes and riding.

It's refreshing to hear about kids having positive interests. Have fun promoting that interest as much as possible, even if you don't want to ride a bike yourself.

All the best.

Al