Posted by: craw
I was researching this very question recently and everyone I spoke with loves the DT Swiss EX 511. A little bit heavy but most had used them for a long time and were still holding air nicely.
x2 for this. I actually use the DT Swiss EX471 (25mm Inner width versus the EX511 30mm inner) rims because I'm still not totally a wider (and heavier) rim fan boy but these rims are about as good as aluminum rims can get. I've had a set that I have been seriously abusing on and off for 3 years now and they are still going strong. The back one will probably get replaced in the next year as it does had some very minor dings and flat spots but for 3 years I'd call that good value.
These days though carbon rims are a temping option if you can get ones that are built to take abuse and don't try to go too light. I have a set of Light Bicycle (LB) rims on wheels that I had built that I'm also super happy with. I initially cracked the rear rim with a heavy rock strike on the rim edge after only a month of riding but they replaced it under warranty and offered to give me a extra heavy layup (only maybe 50grams heavier) on the replacement if I was okay with that option. I took them up on that offer and have not regretted it. Overall the wheel is about the same weight as the EX471 but the great thing about carbon rims is that unless you crack the carbon, all you have to do is periodically check spoke tension and they'll stay as true and round as the day you bought them. That is, at least, until the day you crack them in which case you can pretty much throw them away and start over. They are also pretty much at least twice as expensive though (for the bare rim), even for cheaper off brands like L.B.. Because of this I doubt I'll go carbon again the next time round as long as the DT EX rims are still available but it really is a tough call.
BTW, my riding weight is around 235 lbs and I like to plow (Ned's on Seymour may be one of my favorite rides on the North Shore) so when a rim lasts for me, I'd say that's a pretty good recommendation. I actually don't understand how rims this light can take the stress I put them through; its nothing short of miraculous. Considering I broke the damper rod on a DB inline, and aerated a freshly bled RS Super Deluxe in about 3 months riding and cracked the rotating shock link on my last bike, I have to say if wheel lasts for me it should last for anyone short of a world cup downhill racer.