I am thinking about building a set of race only wheels using a semi deep section aluminum rim. How much advantage is there to tubulars, it seems like they are lighter and better riding but require more work. This seems reasonable for race wheels. I am looking at a used set of cxp30 tubulars and ambrosia thesis. any experience with these rims should i look elsewhere? I am a pretty big guy ~190lbs and pretty tough on wheels and will build these 32 3x with wheelsmith xe14 spokes so they are stiff ut still light. any suggestions?

If you want the really lightest wheels possible, you do have to go with tubulars. However, those are CF rims. You may find that your rims of interest are really not much lighter in the tubular version than in the clincher version. If you have not used sew-ups before, you will have a whole new technology to learn: gluing, on-road replacement, repairing, maintaining your spares, etc. If you ride in really hot conditions, you will be a little more challenged with glue failure at your weight. IMO, for CXP30s, you will not be getting a noticeable jump in performance compared to clinchers.

Unless you plan to be off the front by yourself, a lot, you might be better off with a lightweight rim. Tubular CXP30 rims are pretty heavy. In a pack, a lightweight rim will help you more, because your front wheel will be shielded from the wind by other riders. When it comes time to sprint, a lightweight tire/rim combo will help you more than a heavy aero combo.

You can have light and aero CF rims but they aren't cheap. From my jaded view any more than 3 spokes is too many!

When it comes time to sprint, a lightweight tire/rim combo will help you more than a heavy aero combo.
Only if you plan to follow another rider to the finish line. In any reasonable scenario, a heavy aero wheel is faster than a lighweight non-aero one if the rider isn't drafting someone else.
http://www.analyticcycling.com
http://biketechreview.com/archive/wheel_theory.htm

Yes, but the whole race you have to lug around a heavy wheelset. If you do it right, you come around the last rider with 20 feet to go. If you're the type of rider who breaks away, quite often, they may make sense.
Call me old fashioned, but I can't see crashing on a carbon wheelset.

Yes, but the whole race you have to lug around a heavy wheelset. If you do it right, you come around the last rider with 20 feet to go. If you're the type of rider who breaks away, quite often, they may make sense.
Call me old fashioned, but I can't see crashing on a carbon wheelset.
Run the numbers. Even sitting in a pack, aero counts more than weight. In a pack, a 2% reduction in drag equals about an 11 lb reduction in weight. Aero wheels are capable of reducing drag by 2% for much less than 11 lbs.

And why are you bringing crashing into the discussion, that's a value, not performance, judgement.

Tubulars: I like them and no I'm not even an old retro grouch. People seem stuck on the idea that non carbon tubulars don't offer any benefit over standard clinchers, but they do. For example, compare a relatively identical Mavic Open Pro vs. Reflex build. Using advertised weights, you save roughly 45 grams per rim alone. Compare conti sprinters at 275 grams vs a conti gp3000 at 220 grams + 80 gram tube and you save another 25 grams at the outermost part of your wheel. Rim tape vs. glue are generally considered a wash.

Compare Veloflex criterium at 240 grams vs. veloflex pave 180 grams with 70 gram latex tube and you still saving 10 grams. At least 100 grams dropped off the outer edge of your wheels IS noticeable. True, it might not affect your results, but it makes much more sense than paying $80 to save 8 grams with that carbon bottle cage! I find my sewups to be a nice mental boost if nothing else and can vouch from personal experience that they handle better and flat much less often (especially the handmade ones like Veloflex crit). After replacing pinch-flatted inner tubes and slashed Paves, the Criteriums or Sprinters don't really cost much more either. Dealing with tubulars sounds like a lost vodoo art, but it just isn't that hard, especially if you're intending these wheels to be race only. Sorry for preaching to the choir.

Grumpy mentioned that he can't see crashing on a carbon wheelset and I agree with him. Yes, it's a value statement, but not something people always think about it. I don't earn a paycheck racing crits, so crashing a pair of zipps doesn't make sense. If you're intending these to be crit only wheels, I would go with the lighter low profile rim like he suggested. "Run the numbers" all you want, but I have never, ever done a crit with 32 spoke wheels (or my Protons) and thought "Gee, wish I had used my Shamals." I have, however, regreted the decision to use my aero and heavy Shamals instead of lighter rims. The Shamals are great road racing wheels but not my first choice in a crit with constant accelerations. There are also intangibles to consider, like the quicker handling from a lighter rim or the ability to jump on someone's wheel with less effort. If you're an idiot like me who tries long breakaways or are too tired/stupid to get on someone's wheel when they attack, the aero wheel will indeed make it easier to catch back on over a 1/2 mile while you are gapped off, assuming you don't have a hairpin turn in the middle of it. If I remember correctly, I also saw one of the owners of analytic cycling win a very competitive crit on, you guessed it, low profile rims.

To answer your question, based on the 40-50 gram difference between an open pro and reflex rim, I'm guessing the CXP30 vs. 33 difference would be about the same. From what I've heard, CXP33 is a strong rim, and while it's not much more aero than an open pro, it's not much heavier either. If you're hard on rims and looking to run low spoke counts for an "all-event" race wheel, the CXP30 is probably a nice choice. Also, check to see if Velocity makes a tubular version of their aerohead or deep V, depending on your race intentions.

If I remember correctly, I also saw one of the owners of analytic cycling win a very competitive crit on, you guessed it, low profile rims.
Which of course means absolutely nothing. It's been said here time and again that in the vast majority of cases results are totally independent of equipment; that the difference in ability level between riders is usually greater than the difference equipment makes. There also could have been many reasons why that one rider on that one day chose to ride the wheels he did which had nothing to do with what wheels he thought were faster.

That does not mean, however, that there aren't demonstrable differences in performance with different equipment, and aero wheels are simply faster than low profile ones in every condition except extreme hill climbs. Everyone is entitled to their opinions and perceptions and there's no arguing if someone says they feel faster on one set of wheels than another. Nevertheless, every test whether through modeling, in wind tunnels, or on the road has shown aero wheels to be faster than lighter less aero ones.

Finally, whether closing a 1/2 mile gap or jumping on someone's wheel, accelerations are so slow that they are insignificant. The great majority of power in both cases goes into overcoming drag. The data at biketechreview.com from a Pro,1,2 crit demonstrates this nicely.

"Nevertheless, every test whether through modeling, in wind tunnels, or on the road has shown aero wheels to be faster than lighter less aero ones."
Tests are tests. Racing is racing. If the numbers are correct, the differences in a large pack must be minimal. As you said, it all comes down to what you feel better on. Going into the final turn, I feel better knowing that I'm not going to crunch a $1200 wheel set, and that if I go down, I will only have to lace up a NOS rim that I have in my basement. ( GL330's or Wolbers )