Gabriel was left with the very original 12" bike he got from REI so many years ago, which he accepted good-heartedly so his younger siblings could play on the bigger bikes. That $100 investment of a "good" bike was way worth it!
We'd always had a slightly different view of bicycles than many families, seeing them as communal resources to be used as fit for a given member -- so, not "gifts" or "mine," but rather, "use what fits you now." That's much easier to implement when the oldest is a boy and there's no pink involved, and when Dad scrounges bikes from neighbors discarding them.
Now that there are two households, I see no reason to diverge from this perspective -- indeed it becomes a practical economic reality. Bikes, ski boots, jackets -- it's all in one, guys. So I'm glad to see you sharing!