As discussed in this thread (http://www.bikeforums.net/general-cy...ild-pedal.html) I think you'd be better off teaching them balance first then pedaling for the reasons I explained in my post (http://www.bikeforums.net/19379183-post30.html)

And I'll second atbman's Islabike's suggestion. My son is on his second. Started on a CNOC 14 at age 3 and got a Beinn 20 Small for Christmas (age 5). My only gripe with the CNOC 14 (purchased in 2014) was the coaster brake and lack of rear hand brake. I rectified that with a BMX hub, caliper brake, and spare lever from Islabike's. The new CNOC 14's have a rear hand brake now and Woom makes a cheap 14" freewheel hub wheel to replace the coaster brake one (wish I had known about this before I went the expensive route I did).

The Beinn 20 is simply awesome if you child is ready for more than one gear.

DSC_8505 by joe jackson, on Flickr