what would be the speed difference between an S40 with high end wheels and a stock V20C be?

[The Brook]

I'm having a fantasy about winning a fair amount in our Canadian lottery, thinking about what the difference in speed would be if I bought an S40 Frameset, and build it up with either Roval Rapide CLX III, or Zipp 303 Firecrest or 353 NSW wheelset, or, maybe an Envy SES 4.5 wheelset, lightweight gearing and Sram red AXS hydraulic brakes.
And compare it to a Stock V20C, what would the speed difference be between the 2. Add in a Rotor 34x50 oval ring crankset.

The reason for this is I have a neck issue, and am not sure if the V20C's low recline would be an issue, Should it not be one, I could always buy a V20C frameset, and switch over the parts to it. (Ahh, to dream about what you can buy with a windfall lottery win.). But if it should be an issue, how close would the performance difference between the 2 bikes be?

But this is a fantasy for the moment, I can't really afford anything, and I am happy with my old Freerider, I upgraded the wheelset about 18 years ago to a Velocity wheelset, it rides faster, but nowhere in the same league as an S40. But a fun, comfortable ride nonetheless.

 

[Mathew Fy]

I have a neck issue

You’ll probably benefit from Cruzbike’s Adjustable Carbon Fiber Seat (similar to a Thor seat) that elevates the shoulders & head for a more comfortable position. There’s a small aerodynamic penalty at higher speeds, though. Being budget constrained, I recommend keeping an eye out for a used V20 and only change components that improve performance.

 

[Frito Bandito]

That is a tough question I can't answer, but I'll write something anyway lol.


I've been fiddling with my head rest a little lately after purchasing a Casco SP-2 helmet since it interferes a little more in the back than my older Limar SpeedKing. I am going to add a little more padding under my shoulders and adjust the headrest for comfort, but this is going to hurt me aerodynamically. An S40 with good wheels and tires, a good helmet and a good tailbox is gonna be hella fast, maybe even creeping into a little older TT bike levels of CdA. But if speed is your goal then I think the lower seat angle on the V20 is going to trump good wheels on an S40.

Like Matthew Fy wrote above, you can either get the CB adjustable seat, Karl's V20 seat mod (https://forum.cruzbike.com/threads/karls-v20-variable-seat-angle-solution.16642/) or DIY it yourself with some padding from the DIY shop with a used V20 or V20C. I'm going with more padding for now.