For Sale: New Pink deep-v wheelset on system-x double fixed

A note on machined side walls (a recent phenomenon). A summary is that in some ways it is better not to have machined side walls and the machining does not really improve brakeing it's just stops brakes from squeaking.

http://www.rivbike.com/article/components/rims

Machined sidewalls? Nope, and here's why:
A rim starts life as a straight extrusion; and then it is rolled into a circle. Before it's rolled, all's well with the braking surface (sidewalls). But in rolling it round, the sidewalls get wavy. That's because the inner and outer circumference travel a different distance, in the same way as the runner in the inside lane of a track runs a shorter distance than a runner in the outside lane (assuming they start and finish on the same line). If the rim material were stretchy, maybe the outer portion (the part nearest a mounted tire) would stretch and get thin. But it's not stretchy, so instead, the inner portion develops waves, so that despite being on the inside, it still travels the same distance. It's like the runner in the inside lane running a curvy line to make up for his advantage. Is this making sense?

In theory, wavy sidewalls are bad, but only in theory. In fact, the degree of waviness is so small that it hardly matters. However, it is undeniable that perfectly flat sidewalls are the ideal, and have less of a tendency to draw attention to themselves on an initial test-ride. That's the whole deal, right there.

Nobody's happy when a customer applies the brakes and hears a squeal. It doesn't often happen with any rim, machined or not, but statistically it is more likely to happen on a raw sidewall than on a machined one. Because of that, rim makers have "solved" the squeal issue by machining the sidewalls.

You might think, so what's not to like? Well, something.

The side wall thickness starts out even, even as it gets wavy in the rolling. But when you machine the waves flat, you lop off the high spots, and that takes material away from the sidewalls. So although your braking surface may be flat, you end up with sidewalls that are thin here and thick there. Some rims start out extra thick to compensate for the shaving. But in those cases, the low spots that barely get skimmed remain disproportionately thick.

Since the waviness is so small to begin with, we think it's best to leave well enough alone, keep the wall thicknesses even, and let braking itself take care of the high spots, over time. It always does.

Sometimes when rims are machined, the tool isn't super sharp, and the process leaves visible, feelable grooves in the braking surface. While we're splitting hair with waves, we might as well continue it here by saying grooves are bad. They reduced the contact area between your rim and pad, so they make braking worse that way. And they're more likely, than a smooth surface, to trap water.

Machining rims is a way for rim makers to justify a higher price, and the only thing it does is make a rim worse, while making it seem smoother. You can still have a grand old time on machined rims, and they're not likely to cut your tour short. But all in all, we'd rather the rims were normal, and all the rims we sell are. In some cases, we've specifically asked the maker to NOT machine the rimswhen machining them was the default.