I have always enjoyed the Kona bike count and was interested in the data of a more "average" ironman. Using Justin Luau's excellent pics from IM California I spent a few hours doing a count. The top 5 wheel, helmet, and kit brands are included but the accuracy of those is suspect because if I couldn't recognize the brand within a couple seconds it was skipped. Total bikes counted is 1120, which is about the top half of the field.

Brand - Total - Percent
Cervelo - 218 - 19.5
Canyon - 166 - 14.8
Trek - 139 - 12.4
Quintana Roo - 106 - 9.5
Felt - 92 - 8.2
Specialized - 86 - 7.7
BMC - 52 - 4.6
Argon 18 - 50 - 4.5
Giant - 30 - 2.7
Cannondale - 29 - 2.6
Scott - 29 - 2.6
Fuji - 13 - 1.1
Dimond - 11 - 1.0
Orbea - 11 - 1.0
Kestrel - 10 - 0.9
Pinarello - 8 - 0.7
Ventum - 8 - 0.7
Diamondback - 7 - 0.6
Liv - 7 - 0.6
Look - 4 - 0.4

Disc Brake
Yes - 492 - 44%
No - 628 - 56%

Disc Wheel
Yes - 222 - 20%
No - 898 - 80%

Type of Bike
Triathlon - 971 - 86.7%
Road w/ Clip ons - 104 - 9.3%
Road - 45 - 4%

Top 5 Wheels
Zipp
HED
Dt Swiss
Reynolds
Enve

Top 5 Kits
Zoot
Castelli
Wyn
Roka
Santini

Top 5 Helmets
Giro
Rudy
Smith
Specialized
Kask

Stuffed Kit
Yes - 106 - 9.5%
No - 1014 - 90.5%

This last one was interesting- was not expecting so many to stuff water bottles down their kit.
41% of the first 100 had their kits stuffed!