For a 16" bike for my son is a Schwinn or TREK bike better long term with training wheels?

TREK-steel frame
http://www.trekbikes.com/us/en/bikes/200...

Schwinn- aluminum frame
http://www.schwinnbike.com/products/bike...

I like the coaster brake because I don't prefer the hand brakes yet for him. Are there any other brand names that I forgot about? Trek, Schwinn...?

Also, is aluminum better than steel or vice versa?

That's great you want a nice bike for you son. But I don't really have a comment on either. While I have several high end bikes and my two girls ride too, I always bought them cheapo but good 12", 16" and 20" bikes. They just get a couple years of use and they are in great shape when they out grow them anyway. Now that my 10 year old graduated to a 24" I got her a nicer bike and in a few years she have a high quality bike of her choice.

I'm not saying your choices are bad, they are great. If I were to pick one I'd go for the Trek.

I just find most kids bikes durable - almost any problem with them is directly related to no maintenance being done. BTW all the bikes so far have had 2 riders - being handed down to my 8 year old and are still ready for more use.

Even if you went for a "bargain" bicycle, I'm sure your son will outgrow it before he wears it out.

So I'd go for price.

I'd go for the Trek...