Originally Posted by Viich

On the wheel - keep an eye out for sales, pinkbike, craigslist and your track probably has a facebook buy and sell group. If you're able to build and can use some used and discount parts, it's not that bad. In reality though, he's probably at no disadvantage assuming bearings are good and the freewheel isn't dragging. Freewheel engagement is the biggest real performance difference, and there are some really nice freewheels with good engagement around now (box, profile, white industries). The freewheel hubs and freewheel are generally actually a touch lighter than the cassette hubs, so until he's putting down big power he's probably fine. Do the build, but don't feel you have to rush it.

Yea, I'm fully attached to the ground, no air for me on the track. I think I'm going to get her talked into it for this year - that could be a strategy.

The colour is an absolute necessity for the kids and bmx. I unfortunately have one kid that loves blue and one that loves red, but doesn't matter much as they're both on junior bikes. I'll use brass or aluminum for my wheels, depending on what I'm going for, but I agree, nothing wrong with aluminum nipples except the cost.