Rim construction is identical to the Alps. Using RTM construction, the spokes, rim, and hub are co-molded in one operation. Because there are no secondary bonding processes, the H3s are supremely strong. Available in clincher or tubular, 650 or 700. Shimano cassette, or track configuration only. Hubs are wheel-specific, two sealed bearings on the front wheel, one sealed cartridge on the rear non-drive side and ¼” loose ball-bearings on the drive side.
Weaknesses: Untrue, pain to pump (need crack pipe extender)
I've been using the standard H3 front and the newer H3 deep in the rear. It's a great setup, close to my absolute all around favorite except for the fact that the wheels are slightly untrue - which is well known and unavoidable. This makes braking tedious and touchy in important races where you want a more solid feel around tight areas. Other than that, like I said, this is hands down my favorite setup.
Weaknesses: Price, weight, not perfectly trueness and flexibility.
Also handling issue when the wind is high but all the aero wheels with deep rims have that issue
I had this wheelset for last 2 years and I like them. They are durable and fast wheels (as long as the road is flat and the speed is high). They also look pretty sharp.
They are pertty heavy though so if you are planning on racing on a hilly course you may want to consider Hed Stingers, Zipp or Reynold Stratus. They also offer no advantage if you are doing a ride at slow to moderate speed.
I feel the advantage when the speed is 25 mph+.
They are also flexible so if you are planning doing a race that requires constant acceleration its weight/flexibility will hinder your ability. Also the high wind will cause some handling problem.
Another word, the ideal racing condition for this wheelset is flattish road with little wind. I noticed that the price has increased tremendously last couple years.
One thing you have to watch out for when you shop for this wheel.
None of them are perfectly true.
Ann Hed told me that the molding process make it impossible for this wheel to be perfectly true.
She said even the ones Lance used in Tour had some lateral movement.