a helmet is good. I'd add the elbow pads but the wrist guards are usually for skate boarders.
He is less likely to fall with the three wheel kind and he'll hate having to strap on the elbow and knee pads, especially when it gets hot.
If your boy is a dare-devil, then I guess I'd insist on the elbow and knee pads but a few skinned knees might be just the thing to teach him. (is that too hard?? lol)
I just think that if your kids are like mine, well, good luck getting those pads on past the first time. (roll eyes) I have given up and compromised with helmets everytime--except for my DS because he'll go to a friend's place the street over and zoom on a scooter and nobody is there to enforce the helmet (I know, I know. I don't know how to enforce it when he's there without me... you know kids. big sigh.
me:43, DH 44
DS: born by c-sec Apr15'03, 9lbs5oz 41wks gest. (after 4 years of ttc, starting in 1998)
DD born by c-sec Oct 13 2007, 8lbs13oz 39wk gest. (after just under 3 years of ttc)
~~DS was conceived naturally the cycle following a cancelled DE IVF, using my good friend's eggs. She was on the verge of hyperstimming.
~~DD's nat conception I attribute to using OPKs like a crazy nut, eating grapefruit daily and using preseed. also 5 cycles of TCM ending 2 cycles before that lucky cycle.