Astute readers of the blog will be aware that we've been testing a new rim for a couple of months now, and will likely have been frustrated with our caginess regarding same. Last night, I got a text from Interbike, where said rim is being shown, that said "dude, people are going GAGA over these!" To which I replied "well, duh - welcome to the first time I've said I told you so." Product announcements are always hard to time, but at the risk of making everyone want these before they're available (we'll be able to start shipping them in November - what a great month!), here you go. We've got roughly 1500 miles on a set of AForce AI33 rims, and they're great. I'm actually the first person in the US to have built or ridden a set, and it's been fun to sit back and read what the peanut gallery's had to say online while I've been secretly riding around on them.
Specs are pretty simple: 32.5mm deep, 19.6 inside brake track, 24.2 outside brake track, 26.2 max width, with a nice 9mm tall brake track. Per rim weight is 470.5 (it's claimed at 465, ours are 470 and 471). The extrusion thickness at the nipple bed is 2.1mm, which is thick for a performance-oriented and weight-conscious rim. The shape, as you can see from the pics, is toroidal. They are made of a 6000-series aluminum alloy variant that is claimed as harder and stiffer than normal rims. I can vouch for the stiffness, and they sound different from other alloy rims when you're handling them. Durability has been on fleek to date (see what I did there?).
The set we have has internal nipples and 2:1 lacing on the rear, as well as the optional ceramic brake track. Our inclination is to stock and do standard builds with external nipples, 1:1 rear lacing, and do the ceramic brake track. With so limited a universal of test rims, we're testing what we were given to test. Given that they are absolutely arrow straight after what I've put them through, I'd be fine going with internal nipples but people generally hate them. 2:1 lacing solves for a situation (inadequate non-drive tension) that hasn't been an issue in thousands of our builds, and it leaves a LOT of space between non-drive side points of control (like 8"). The ceramic brake track is a huge part of the story, though, and I can't see us selling a single set without it.
Most people just looking at the wheels assume they're carbon. The ceramic brake track has developed a sheen much like what you'd see on a carbon brake track. The wear is even. The rims still look great. I'm far from a maintenance freak, and since the supplied pads got lost in transit I've been using a set of the carbon pads we used to supply with older generation Rails. At first I used pads for alloy rims and they freaked me out with how much pad slough (new term, there) there was. BikeRadar experienced a similar thing with the supplied pads in their review of them. The Rail pads have had none of that, they're dead silent, and they brake at par with Easton and HED rims (which is to say as well as any rim I've ever used). I don't know what effect they have on rate of wear, but since the rate of wear using them is so darn minimal I think I'm glad that we have a large box of leftover pads to use with them.
As to the aerodynamics, we can't yet say precisely (as you know, saying without knowing isn't our game). We're coordinating a significant wind tunnel trip (A2 will do the testing) that will give a definitive look at how these compare to standard-bearer carbon wheels (404s), shallower carbon wheels, and other alloy rims on the market. Expect that to happen within about the month. From riding, I can tell you that they aren't slow, and that they are as manageable in crosswinds as any wheel I've used. Tire installation is easy, and the tubeless interface works great for road. Haven't tried a CX tire on them yet.
Our enthusiasm for these is a continuation of the philosophy we've been developing for almost two years now, that resulted in our decision to end the Rail 34, and coming to a peak with this post I wrote in May of this year. A tubeless-compatible carbon clincher of this width, depth, and assumed aerodynamic profile would weigh not less than 20g per rim less than these, at somewhere starting at somewhat more expensive than these (for "who knows where it came from" eBay/Alibaba carbon) to 4+ times as expensive for super premium options. The final analysis will hinge somewhat on what A2 tells us, but so far these are among the nicest road wheels I've ever used. It's something of a golden age for alloy fans as the Easton R90SL slots right into that group, too. And I've ridden darn near everything.
So there you go, some breaking news for you.