I've got a deal on pair of DTswiss 240s centerlock hubs, 32 holes and probably going to use sapim laser spokes as I can get them on the cheap and I've actually built 2 wheelsets with them. Now for the rim - I've narrowed my choices to the following Dt Swiss r460 disc Mavic xc421 disc Wtb frequency i19 cx or team version Alex rims Volar 2.1 I'm about 220lbs/ 100 kilo and the bike is Viner Strada Bianca, which has tons of clearance with 38mm tires, so much that I think I could fit a 2.0 29er tyres. So which rims would be the best fit?
I don't think and others have said - Sapim Laser's are not a good choice for disc wheels, even Sapim says so. That you are a big guy is not going to help, either. CX ray or Race, maybe even D Lights would be better choices.
R460 are road or cross rims, to take only up to a 35mm tire. Do you run tubeless? Run a wider rim. The lighter XC rims should be fine with your weight. Gravel riding just isn't as punishing and demanding on wheels, like mountain biking.
Have you considered Velocity Aileron's? The Deeper rims will be stiffer than the shallower XC rims. There is also a bomber Kinlin disc rim that is 31mm deep, but building it 32h hole might be even overkill for a 220lb rider.
Kinlins are hard to find here in Europe and Ailerons are over my budget. I actually have unused Alex EN24 disc rims in my garage, but they 're not tubeless. I used DT revolution and sapim lasers for my previos disc wheel builds, I didn't have any problems riding those wheelsets. But then again 8I weighed 8 kilos less.
There is a deal on 650b WTB KOM i21. I'm not sure on 650B, though, never ridden a bike with that wheel size. There shouldn't be much difference in geometry if I use 650B with 50mm tyre and 700c wheel with 38mm tyre by my counting
