How long will a 12" bike fit?

[pb&j]

DS is 3.5 and is ready for a real bike (w/training wheels). He's about average height for his age (41 inches or so), and I'm wondering how long a 12" bike will last him. Will he be able to fit on it for another year? Two? And about how tall would he have to be to fit on a 16" bike?

[o_mom]

DS2 got a 12" bike for his 4th birthday, but switched to a 16" within a couple months as soon as he was very confident on it. He is not tall, around 25%. He had more difficulty with the 14" than the 16" because of the way the bike frame was shaped, though, so it can vary by bike as well. All of our bikes have been used, either from family or CL, so we didn't have much invested in them other than a few replacement parts here and there.

[KrisM]

DS got a 12" for his 3rd birthday and upgraded to a 16" at age 4. He was probably about 40" at age 4. He's 43" now and the 16 is getting a bit small and he really wants a bigger bike so he can go faster.

[LarsMal]

We just got DS a 16" for his 4th birthday. He is average height and I think it is just a little too big, but the 12" was definitely too small. I think the 14" would have been perfect, but they are hard to find. TRU had a couple, but they didn't work out for different reasons.

In the end we got the 16" knowing he'll be on training wheels for a while and will grow into it instead of growing out of it very quickly.

[pb&j]

Thanks, y'all. Looks like I'll start shopping for a 16" bike instead. DS will be thrilled!