My impressions...
Keep in mind that I'm riding 48x16 fixed gear and speeds >25 MPH will be rare.
The build is:
- RRU35C02 rims - 25 mm wide, 35 mm deep, 3k matte with grooved graphene brake track.
- Mack Superlight track hubs.
- Brass nipples with CX-Ray spokes, 24-2x rear, 20-radial front.
Rolling: They are round and true. They hold the tires on. No big surprise.
Mounting: Mounting Vittoria Rubino G+ Speed was more difficult than any other road rim I've used. These are also the widest road rim I've ever used.
Weight: I want to say "Lack of inertia" rather than weight. They are 1/3 lb lighter than the old wheels and almost all of that inertia is/was at the rim. Less inertia to overcome can be felt when rapidly changing speeds such as jumping out of the saddle to speed up. Accelerating from a red light is exactly the same from stopped through about 12 MPH but once the pedals and wheels get spun up a little I can accelerate through 18 or 20 MPH or so much easier.
Ride Quality: The radial stiffness of the deeper rim can be felt. They feel harsher than the old wheels when crossing expansion joints and road cracks. Tires and pressure are the same as the old wheels. I'm running cruddy tubes. I will be experimenting with pressure a bit.
Aero: Yes. The tire and rim width are within 1 mm of each other whereas the old rims were a little narrower. The extra depth, true aero profile vs deep V on the old rims and CX-Ray spokes could be felt as slightly less effort when going fast, <20 MPH. It is subtle but I believe it can be felt. Keep in mind that I'm the guy who claims to be able to feel extra drag when my hands are on the tops of a flat aero handlebar vs the hoods.
Braking: This is my biggest concern. Black Prince pads have a bedding in process which I did. Panic stops seem OK. Modulation doesn't seem as good as the alloy rims - they seem to lack a little lever feel. Maybe I just need to get used to them over time and part of it is probably the difference between Koolstop salmon pads on the old rims and Black Prince on the new. Toe-in on the pads needs to be adjusted better as well. The sound isn't as obnoxious as some carbon rims I've heard - I was expecting worse.
I'm happy with them and they changed the look of the bike completely.
-Tim-