So, yesterday we talked about some of the challenges of going to 11 speed from a wheelbuilder's point of view. It's still early days and there aren't a lot of 11 speed hubs that have hit the market, but we know that the cassette body is wider, which means that the drive side flange is moving in since that's the only way to accomodate a wider cassette.
Campagnolo has had the wider cassette for a while now. By and large, the drive side flange on hubs for Campy are 2mm closer to the center of the hub than on hubs for SRAM/Shimano 10 speed. Some wheels basically ignore this difference and just have the rim a little bit off center. I don't love that approach, and we don't do it, but there are big companies out there who sell a lot of wheels like this.
Campagnolo's approach for their own wheels has been 2:1 lacing. This puts two spokes in the drive side for every one on the non drive side, like in this Bora. With half the spokes on the non-drive side, each one does double the work, therefore the load on each one is doubled and the tensions between drive and non-drive are more equal. This is a great solution for pre-built wheel "systems" where the components (hub, rim, spokes) are all dedicated to one another, but it does present logistical problems to wheel owners. If you crash and bust a rim, getting just a replacement rim is somewhere on the scale between "expensive and difficult" and "just plain impossible." Spokes for these systems have a tendency to be challenging to get and expensive. These things can be game breakers for a lot of people. Your options are also limited in terms of which rims and hubs will allow you to build a wheel like this. Rims need to be drilled in multiples of 3 in order for this to work, meaning that the only currently popular and widely available drilling that works is 24 hole. For a lot of purposes and riders, that's just not enough spokes. It's not just number of holes that is the issue either - spoke holes are drilled directionally, so a 24 hole rim that's drilled for normal lacing doesn't work as a 2:1 rim.
As one commenter wrote in response to yesterday's post, there is also the option of doing an off center rim. I love this idea, and have been working to get our alloy rim supplier to do it.
The other option is to put really hard spoke tensions on the drive side. This doesn't stiffen the bracing angle of the drive side at all (some people think high spoke tensions stiffen the wheel, but once you have enough tension to keep spokes from going slack, it doesn't) but it does allow you to get the non-drive sides hard enough that they don't go slack. On our carbon rims, we can use PLENTY of spoke tension, so getting enough non-drive tension is no sweat. Some carbon rims have a 100kgf spoke tension limit, and many alloy rims do as well. With those rims, this option is closed to you.
You can do some funny things with drive side spoke lacing to eke every bit of room out for the flange. Radial drive side spoking with with either j-bend or nail head spokes lets the flange get a bit further outboard since crossing the spokes requires room between the flange and cassette. Eliminate the need for that space and you get it back for the flange. I'm not a huge fan of this since then you have to pass the drive torque through the hub and the crossed non-drive side spokes actually do the driving. There are a bunch of wheels out there that are made this way but I don't have to like them. (the wheel pictured doesn't take full advantage of this, as the spoke heads could be inside the rim and the spokes go outside the flange, but it was the best picture I found to illustrate the deal)
So, just kind of a primer on some of the issues of the change to 11 speed and letting you know that we're working on it. Even if you don't wind up using 11 speed yourself for a while, this is an issue that you'll probably deal with since the majority of hubs will want to accommodate 11 speed.