Let's be honest, I'm more of an MTBer than a roadie, but it's safe to say that I've done a bit of road riding in my time, particularly over the last year preparing for the 6,800km Trans America Bike Race in June 2015.
So what have I learned about the Curve Cycling 50mm deep carbon road wheels? Here's my executive summary... in my coast to coast race across the USA, I had zero issues with the wheels. None. Despite riding a fully loaded bike (food, clothes, bedding and everything needed to keep me safe) and across some terribly rough roads (back roads in Wyoming and Colorado can be rough!), there was no need for any maintenance on the wheels whatsoever. None. Zilch, Zero, on these, a set of lightweight carbon race wheels! That's all you need to know, case closed! But, if you are after some more detail, then please read on...
The 6,800km Trans America route was 100% sealed (except for about 30 km of road works, where I rode on gravel or worse!) and I wanted to go fast, so I needed to pretend to be a roadie for a month or so. My frame and wheels were the two most critical pieces of kit in my setup. After all, they're the most important components affecting the ride quality of a bike. My frame choice, again with bias, was the Curve Belgie Disc Titanium Frame; road racing geometry and built for speed, not touring.
The first time I stepped on the bike I was amazed by the power transfer - there was simply no loss of power. When accelerating it felt like there was zero flex in the frame and zero flex in the wheels - more power than usual was transferred straight to the road. Of course, stiff carbon-soled shoes helped. As did my super stiff THM Carbones Clavicula cranks. I'm exaggerating here; of course there was some flex, but compared to my other bikes it was on another planet!
The other thing I noticed was the ease with which I could increase my pace once already rolling. The effort required to accelerate from 30 km/hr to say 40 km/hr felt much less than I was used to. I suspect this was the aerodynamic impact of the deep dish rims. I don't have any hard data to back this up, I'm just reporting on how it felt to ride.
The first test for wheel toughness was in transit. The plane trip to the US wasn't a great one for my bike. In my situation, with different arrival and destination points, a cardboard bike box was the only real option. When it popped out at over-sized luggage, I was mortified to see that it had been crushed under something heavy. The front wheel, packed to the side of the frame took most of the load, closely followed by the rear triangle of the frame. Once unpacked I saw my derailleur hanger had been folded and thankfully my front wheel had survived and only developed a very slight wobble - only a fraction of a millimeter, but enough to notice. I had to replace the hanger, but after speaking with Steve (Curve founder and product developer), we decided to not bother working on the wheel. 6,800 km later the wheel had the same minor wobble - nothing more; still nothing to worry about.
To be honest I'm surprised the wheels didn't need any work along the way. These are road racing wheels, and I was carrying a heavy load across a wide variety of surfaces. While the course was bitumen, there were times when the roads were unavoidably rough, with plenty of potholes and gaps between sections of road. Or worse still, when I was tired, not paying attention or it was dark and my light wasn't throwing far enough down the road, I'd smash straight into pot holes. This happened too many times count, and every time I'd cringe thinking that I'd just blown my wheels, but I had nothing to worry about; the wheels just kept rolling.
So, I guess when people ask me if the 50 mm road rims are any good, I can now point to a pretty solid test and say they stood up amazingly well. Pair these rims with some DT-Swiss 240 hubs and you've got an incredible set of wheels. Before I go, I should mention that I can't speak for the braking surfaces because I rode with disc brakes - you'll have to ask someone else about that!
Wheels, as tested (more detail on the bike is available here):