Aero bike vs climbing bike for running in Crits I'm considering building a road bike and getting into running Crits this Summer and I'm unsure as to go with an Aero bike or a climbing (lightweight) bike.

Based on my general understanding, when not going up steep hills (which of course is not done in Crits) as a general rule of thumb an Aero bike is definitely faster.

Based on this I would have expected to see most Crit riders on Aero bikes, but when I watch YouTube videos of Crits most of the riders are on lightweight bikes.  There are only 3 reasons I can think of for this:

1) Cost, non-professional riders may already own an endurance bike used for long weekend training rides or commuting on rough roads and not have the $$$ to drop on a 2nd bike just for running occasional Crits.

2) If in the pack most/all of the race, some degree of the Aero benefit would be negated (of course this is not a very good reason b/c if you intend to win then obviously you would not be in the middle of the pack, at least not in the end).

3) Most Crit circuits have frequent turns, perhaps endurance or climbing bikes are better for this purpose?

Even considering the above reasons, the whole point of a Crit is to go absolutely as fast as possible for a relatively short amount of time, therefore I would have expected to see almost all Crit participants on an Aero bike, but from watching Crits on YouTube is seems very few Crit riders use an Aero bike.  Can somebody explain this further?
Revised following clarifying comments


OP is / will be racing in the US 
USA Cycling has looser rules for bikes than the UCI, unless the event is qualification for a non-US event.


With these updates, the answer is simply that people rarely race on ideal equipment. Most people I know who race Crits do it either on the same bike they use for road races, Gran Fondos, or other big rides, because they don't have a more suitable bike for the purpose. Those who can afford to drop $5K to $10K on a specialist bike usually don't see Crits as the target: too many crashes, and they tend to see Crits as training rides.

Regarding the bikes you mention, they both appear on a quick glance to meet the USA Cycling Rules 2017. I was initially concerned that the curved top tube was non-compliant, but this guide and the rules already mentioned show that concern to be unfounded for racing in the US. I suspect the FM098 would not meet UCI standards, but that's irrelevant to you.

The earlier version of this answer follows and may be useful for international readers ...



ARTICLE 1.3.011 (and related articles) of the UCI Technical regulations essentially says only a general purpose bike can be used for road racing (criteriums are road races).

I interpret your aero bike to be a time trial bike. The rules explicitly ban such trials bikes from road racing. 

The reason for this is the lack of maneuverability. 

In practice you'll get much more benefit from sitting on the guy on front. 

See UCI CYCLING REGULATIONS PART 1 GENERAL ORGANISATION OF CYCLING AS A SPORT  

Especially 1.3.022 and 1.3.023.