Looking for a bike that "feels" fast

[Lugan]

less stable and twitchy bikes feel fast, but usually that's not a good thing. i like a bike that allows me to go fast while feeling firmly in control.

This! Doubly true with a mountain bike, by the way.

[wheelsONfire]

I rode first gen Foil and Mavic CCU. That felt very fast and super nimble. But i was (and still am) too much of a sensible primadonna to handle these types of bikes.
I got real tired from fatigue.
You can also check the shape of tubes on the bike which also helps making frame either stiffer or more compliant.

BTW riding UP + Grit fork, then jumping over to Vial EVO D, that is hell of a difference (sure, suspension gravel vs road bike).
Ofcourse Vial EVO feels much quicker and more nimble, but it also deliver much more feedback.
It's no masking of the surface you ride. UP with Grit on the other hand is a much plusher ride, but also more like a tank compared to Vial EVO.
I guess any light/ thinner wall frame and super stiff frame will be more unforgiving.
A frame with higher mass will likely ride more muted.
Personally i would go for a more muted frame if i was looking for a new.
I also think a super stiff frame will feel faster as it may be very little give.
Question is if you'd like that feel in the long run!?

[TheKaiser]

Super stiff frame and pump up your ties to very high PSI. It'll feel fast. None of this "vertically compliant" stuff. When you are buzzing along the road and you feel every road imperfection -- it feels fast. Of course, you won't last long and rolling resistance studies have shown that lower PSI/more compliance is actually faster.

Yes, this. ^^^^^^

Plus, switch to 19mm wide tires, and the thinnest bar wrap you can find. Also, when looking for frames, look for one with a 31.6 seatpost diameter.

[sawyer]

Super stiff frame and pump up your ties to very high PSI. It'll feel fast. None of this "vertically compliant" stuff. When you are buzzing along the road and you feel every road imperfection -- it feels fast. Of course, you won't last long and rolling resistance studies have shown that lower PSI/more compliance is actually faster.

Yes, this. ^^^^^^

Plus, switch to 19mm wide tires, and the thinnest bar wrap you can find. Also, when looking for frames, look for one with a 31.6 seatpost diameter.

You forgot the 35mm bars and carbon saddle

[mattr]

You can also check the shape of tubes on the bike which also helps making frame either stiffer or more compliant.

Not in carbon. Unless you cut it up and look at the layup. Which is far far far more important than the shape.

[wheelsONfire]

You can also check the shape of tubes on the bike which also helps making frame either stiffer or more compliant.

Not in carbon. Unless you cut it up and look at the layup. Which is far far far more important than the shape.

I discussed this with two companies building carbon frames and they both tell me, the shape is indeed adding.
Foil has a triangular shape which is adding to the stiffness.
No real shape that allow any flexing. This also help to add stiffness.
Many aero frames is flatter (boxed/blade shape), thinner up/down, wider at the sides, allowing bend sideways (not so appreciated), some frames has a boxed shaped down tube, with the flatter section facing front wheel, this allow some flex up/down (look at UP for instance).
UP is having a layup at the sides to avoid twisting.

Yes, ofcourse layup is paramount, but also in conjunction with shape.

[wingguy]

You can also check the shape of tubes on the bike which also helps making frame either stiffer or more compliant.

Not in carbon. Unless you cut it up and look at the layup. Which is far far far more important than the shape.

They're both important, especially if you want to achieve your aim with the minimum weight penalty of added material. You would also hope that good engineering departments have unified goals across the design process. So (unless you're looking at third or fourth tier frames that have significantly compromised material and manufacture for cost saving) you should be able to assume that if a tube looks like it should flex it won't have a carbon layup designed to keep it highly rigid, and if a tube looks like it's supposed to be extremely stiff it wil have a layup that isn't going to throw that away.