It’s amazing, the transformation that comes on two wheels — or, two in-line wheels with a couple of smaller ones in back.

I remember the freedom, the authority and autonomy that came with my first bike. Even with the training wheels on, my bike was my ticket out of the driveway. Within a year or two I had graduated to a “real” bike, the Schwinn with the red-white-and-blue banana seat. It was my magic carpet that led me on expeditions to parts of the neighborhood I had only seen from a car window, and therefore hadn’t really seen at all — the sloped curbs I could ride like waves, the cement driveways with deep culverts housing pools of tadpoles or the occasional crawdad mound, the back alley behind the Super Food and the scratchy brush of tree limbs in my face as I raced along the sidewalk and past the house on the corner with the chain link fence that barely, just barely, contained a snarling, lurching beast of a dog.

My bike transported me blocks away in mere minutes. I affixed playing cards to the spokes with clothes pins and I was immediately cool. I built wooden ramps and raced down and up ditches and imagined I was Evil Knievel, whose attempt at blasting over the Snake River Canyon was embossed on my lunch box. On my bike I could move faster than I ever had before, which is as important to a little boy as, well, as it is to a grown man. I was no longer earthbound. My feet moved through the air, my legs pumping faster and faster, and the more I worked and the harder I peddled the faster I moved, with the warm Houston air in my face and sweat flying from my brow. I could push my baseball glove over one of the handle bars and take myself to practice, or roam the various ball fields on Saturday mornings, looking for a spot in a game. And I could coast, cool, slow, one-handed, past the girls, and pop a wheelie.

I saw a glimpse of Ella transformed this week.

Ella is the youngest, by a few weeks, of the five kids on our block; four of the kids are separated by nine months. They all have bikes, except Ella. Until recently Ella’s been content with her Big Wheel. But she tried a couple of the bigger kids bikes, and she took to it naturally. All the parents know that Ella’s birthday is coming up (at least, all the mothers seem to know the kids’ birthdays) so one boy’s folks loaned Ella their son’s first bike, a little BMX type with 12-inch wheels. It’s blue. Ella instantly fell in love with it. It’s Noah’s bike, she knows that. She knows it’s a loaner until she gets one, for her birthday, in about four weeks.

Ella has a helmet; we bought it when we bought the bike trailer (which I’ll be selling soon). But she’s taken to Noah’s bike so well — she rides about a half-mile circuit almost every day — and she seems so fearless, screaming gleefully as she zooms down a hill, that Trish bought her knee- and elbow-pads. They came in a set, pink with big flowers, and they have gloves. When I talked with Trish from work on Tuesday, she said Ella was walking around the house wearing the gloves and nothing else. She’ll strap on the pads and walk through the garage, skinny knees akimbo, accounting for the oversize protection, as seriously and earnest as Jeff Gordon headed for the rainbow car.

Of course, we never would have been caught on a bike wearing a helmet or pads when I was a kid. I’m sure they existed, for some kids, like the Bradys. I think our parents considered the bicycle part of life’s evolutionary challenge; they figured it was worth saving a few bucks to see if we could survive.

Now, Ella’s part of the pack of young riders, circling the cul-de-sac, giggling preschool speed demons. Ella is still the most reserved of the kids, the least likely to initiate play. She still won’t scream and squeal on the playset. But just the other night, sitting on her bike, she saw Noah in his driveway. “Come on, Noah!” she shouted. “We’re riding our bikes!”

When Ella parks the bike in the garage at night she moves other toys around it — her big plastic car, her shopping cart, the stroller — essentially hiding it from view. We don’t know if she’s trying to protect it or if she thinks it might break free one night and roll away, a colt bolting from its stall.

As much as Trish and I love seeing Ella grow and watch her begin to master the world, one rotation at a time, we hate it. We’re amazed at her skill, her creativity — tonight she asked to hold my hand while she let go of the handlebars with hers, and tried steering by shifting her weight. Sometimes, though, the wheels turn too fast. We want to apply the brakes, keep Ella close.  But we know we can’t. Tomorrow is Saturday, and we’ll be shopping for bikes before noon, trying to find the right fit, the right color scheme, the right price.

I have a feeling Ella will grow out of her training wheels very soon. And then I’ll need them. I’ll need them for many more years.