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Wee one is just turning 4, he's above average height. Currently riding a 14" Frog with the seat at max height and knees nearly hitting the stem. He's very confident and been riding independently for 12 months so happy to have the saddle at a good pedalling height and tiptoes on the floor, not both feet flat on the floor as most kids bike sizing recommends.
Upgrading to a 16" seems pointless as the saddle is halfway up already, we've tried him on a 20" Frog and Islabike, he seems able to ride them ok with the saddle right down. Islabike do a single speed version but the Frog has gears (though Islabike rep suggested the geared option would be better).
Despite the fact I've watched him on them and had the Islabike rep too, there's something niggling at me that it's silly to get a 20" wheel for a 4 year old, and gears are just more hassle than their worth.
Anyone else out a kid at that age on a 20" wheel and able to put my mind at rest?
My boy was 5. Just stick it in a gear for him and let him go they roll over bumps much better. Even now a year later my boy needs reminders to change gear sometimes
My daughter was pedalling without stabilisers at 2 and went from a 12" specialized to a 16" Isla then a 20" Isla when she was 4. She is really tall for her age and the gears weren't a problem she soon got used to them. Isla bikes are far from perfect but still a better buy than the other options.
all my three boys were in Isla bike 20" Beinn bike by the time they were 4. A little on the big side, but only for around six months or so. There's no holding them back now and they are only just 6.
in fact, here they are today, riding over the bumps
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If he can touch the ground, then go for it. My 5 year old, of average height is on a 20'' Early rider belter. Twist grip 3 gears, and very light. Didn't go for the one with discs or front suspension, just unnecessary weight in my opinion