For what it's worth, I recommend he read [I]Proficient Motorcycling[/I] and [I]More Proficient Motorcycling[/I]. This to alert him to what to expect on the road. After reading David Hough, if he is still interested in riding, get him into a good riding class. Finally, it might be a good idea to make sure he gets a modest motorcycle for the first year or so. This last is to learn to depend on the physical and mental skills of motorcycling and not on power.
OK, I'll say that all that stuff in the previous posts will help but wrt an 18 yo, you have to listen to your inner voice about what kind of person he/she is and reflect on what kind of programming you've left on them as their parent. Because at 18, the frontal cortex isn't fully developed and executive brain function (i.e. decision making ability) isn't fully available until they're 25 or so says modern neuroscience. Basically, Hertz got it right - they won't rent to anyone under 25.
This biological fact is both beneficial (i.e. fearless EOD guys in the military to ground troops with a rifle) and not so beneficial (which is why vehicle insurance is more expensive for them). Only you can decide what you're going to make available to your offspring and if they're ready for the responsibility.
What you don't do if you want a live uninjured kid is hand them a 600cc crotch rocket as their first bike. Many sales folks seem to think these are beginner bikes when they are really suitable only for experienced riders.
Dirt is a great way to begin. I happen to agree with the lack of utility in a lot of current parking lot stuff- all the argunig about slow speed skills and drills being relevant and useful doesn't change the fact that you'll never do anything exactly like most of it out in the real world while dirt sliding will teach you everything you need to know about bike dynamics- and cure the terror of a possible minor off because you'll get to know all about that, too Most people come with a workable sense of self preservation so there's no reason to be unduly worried about a properly equipped kid taking a few tumbles in the dirt.
I taught folks how to make 4 wheeled stuff fast on a track for a long time and can vouch for the fact that there is a lot accuracy and bits of wisdom in pffogs first post in this thread. Teaching how a kid how to ride is a lot like teaching them about firearms- starting young is good and you never compromise on the bits related to staying safe and keeping their brain engaged= eventually its so ingrained they don't need to be reminded and keep working on their skills by themselves. It is true that some folks shouldn't ride- they are the same ones who will never be truly fast on a track with a car no matter how much training or experience they get because the simply do not have the whole body coordination and kinesthetic sense required. Generally, these folks are complete non-athletes who have no kind of athletic interest or experience. Rarely, one sees the precise opposite, a newb who instantly seems to have the solid skills of a veteran- I had one such student in a car years ago and will never forget it- he was could make the car fly fast and smooth right from the beginning and only needed development of race tactical skills to compete...
If your 18 yr old has already crashed a car once or more, I'd stay away from bikes for a few more years. See prior commentsabout Hertz rental age. A kid who dings cars isn't focussed enough to stay healthy on a bike.
Teaching an 18 year-old to ride a motorcycle safely is no different than teaching them about anything else that has some risk associated . . .there is no single shortcut, but a combination of lots of little things, and no substitute for spending TIME with them DOING it. Teach by example. Pick your battles. It never works to tell them 'Do as I say, not as I do . . .' . Ride with them ALOT, and let them lead. Do the MSF classes and safety courses with them. Ride their bike now and then, and if something isnt right, don't criticize, just show them how to fix it. Off-road is really helpful for skill development (and learning consequences of stupidity), but the survivial skills you need in traffic only come from safety courses followed by lots of supervised riding on the road.
I went just a little bit different on my training route. Like many other here, I started him on a small bike when he was 6 (SL70). From there I progressed him to an SL125, KX80, XR250, XR400 and finally a YZ250.
But for the street, I took him to a trackday at Putnam on my CBR900RR. He had only ridden around the block on this bike before the trackday. I entered him in the rookie group and watched him do a little better each session, plus the trackday coaches had a blast helping him. He was 17.
He rode a bit on the street with the 900 but in the meantime I found a race MZ Skorpion 660 which I bought and we both signed up to race with WERA....me again after a 5 year break and him a total rookie. He did the riders school and went out for his mock race and did very well. He now had complete respect for the bike. The next day he entered his first Clubman race and while he didn't win he also didn't come in last.
He continued to use my 900RR when at home but I could tell that everything he had learned at the track worked with his street riding. Like myself and many people he met at the track told him.....if you want to go fast, do it at a racetrack. When on the street have total respect for the machine and ride with the idea in the back of your head that anything and everything can happen in a split second so be ready beforehand.
Since he has been on the track, he kind of lost interest in street riding. He said he would rather ride his mountain bike now!
An 18-year-old's best teacher in terms of safety could be a girlfriend.
Best advice i got as 16 yo new street rider was "this ain t dirt and everyone is not going in the same direction". Also don t ride the bike if you re in a hurry, it can cause careless mistakes. I just took a MSF class this summer and should have done it years ago.
pffog +! Neighbor!
Early Riding stuff
Great discussion on mentoring early riders (regardless of age)...I'd like to add to what's been said.......do you know the person's risk/behavior personality??? I know this sounds absurd if it's your kin......but some folks ......mostly adults are just too agressive to ride a motorcycle safely....I used to promote my rant "Heed NEAD" at safety discussions.....it's always a good discussion mantra......my $0.02!