bigwooly

So i have a problem with my 3 yr old not grasping the concept of the coaster brake. (he'll be 4 next month) He just doesn't get it I'm not sure why. He always says he wants brakes like daddy's and then proceeds to just put his feet down to drag him to a stop. This results in the backs of his poor legs looking like someone has been beating the snot out of them. Also on more than one occasion it's cause him to fall when going down hill.

I've read that my local bike shop can probably add hand brakes. Anyone have any insight on this or how to help him get the concept of using the coaster brake? At this point i'm almost reluctant to keep pushing for his understanding of the coaster brakes since he's getting to the size where most bikes won't have them anymore. He's big for a 3 yr old. Really Big. He's the same height as his 6 year old cousin. Most of the kids at church his age are a good 6 in shorter than him. He just got his 2nd bike it's a twice ridden hand me down Wally World Bike. It too doesn't have hand brakes but does have the place to mount them.

Anyone know where to find a kids bike brake set levers and all? I've called my self looking but either my google-fu is weakening or they aren't easy to find. I'm more than capable of putting them on myself just can't seem to find them anywhere.