The steerer height turned out to be perfect on the IA10's pre-trimmed fork.
IA10 (IAx frames) » Here we show that the Alpha X and Sigma X are perfectly compatible with the new IAx frames. We are even using the aero-matched dust cap included with the bike, although you could use the Alpha X's included ultra-low dust cap to save another 5mm of stack height. And yes, this is a pre-cut fork, as delivered with complete bikes. No need to get an uncut fork.
We are waiting on delivery of a lovely Felt IA10 which we plan to build up and review. In the mean time, we've gotten some questions about the compatibility of the new IA and the original IA with our own Alpha X aerobars. So, this article will lay that question to rest. In short, the Alpha X (and upcoming Sigma X) is perfectly compatible with both the new IAx and the original IA! That's right, the Alpha X can even replace the original equipment of the integrated flavors of IA. And in an amazing coincidence, the very short length of the pre-trimmed IA forks happened to be the perfect length for the Alpha X - we just slammed the bars, and no spacers were needed. The steerer tube was the perfect length, as you'll see in the pictures below. Big thanks to TriBella Women's Multisport for inviting us to check out the compatibility on their bikes.