When is a child ready to switch from scooting to pedaling? Last year, we bought a child-sized bike and removed the pedals. My three-year-old has been using it as a push bike (a.k.a. balance bike, run bike, or scooter) and learning how to balance. The plan is that once she's ready, I'll put the pedals back on, but I won't be adding training wheels. However, I don't want to put the pedals back on before she's really ready because it would be a pain to take them back off again.

She's now at the point where she can coast for about five seconds at a time, but she doesn't ride in a particularly straight line. She often asks for pedals, though I'm sure she doesn't appreciate the effort that will be required.

How do I know when she's ready and it's time to put the pedals back on the bike? What specific goal can I give her to work towards (i.e., "When you can do XYZ, then you can have pedals")?

Related question: What is the best method to teach a young child to ride?
I did the same thing for my son when he was 2. After a year and a half, he just "looked" ready. I knew he could ride so I had him try pedaling. I have a short hill in the front yard and put him near the bottom. He was determined to NOT ride properly, so after about 25 feet he "fell" off and said "SEE!! I can't do it!" I laughed and said, "You did it almost all the way across the yard!" Just then his mom came out and asked him to show her, and he jumped up and rode for a few minuets all by himself.

I made sure that the seat was set so that he could easily touch the ground with both feet at the same time so that if he got nervous he could just stand up, but it never got to that point. He was 3.5 years and my girl was 3.75 years when they both learned to ride (I was a few weeks short of being 8 when I learned)

I don't think there is any magic rule to guide yourself with, just look at her confidence and let that be your guide. Make sure she can touch both feet on the ground at the same time, and it really shouldn't be much different than what she is doing now.

(PS: If you do put the cranks on and she just can not do it, you can always just take the pedals off rather than the whole crank set, that will save a lot of time!)

You can see the video of him a few months after he learned to ride at youtube here: http://youtube.com/watch?v=fnb7uhC1J2Q

A few months BEFORE he learned to ride: http://youtube.com/watch?v=jfrz0Q6I_rw

at age 8 when he learned a "Nothing": http://youtube.com/watch?v=CdOfmWYt9FQ

My girl when she learned: http://youtube.com/watch?v=vP6qio6LS78