Jason, do you think there is anything that can be done about #1 on your list through a design or a materials change? Where is that extra 9 lbs coming from?
It's in the Boom; the Extra chainstay in the front; and the beefed up fork, and the stock handle bars.
Boom = 2.333 lbs
Fork = 1.75 lbs
Frame = 2.75 lbs
ChainStay = 1 lb
Heatrest pipe = .6lb
Seat = 1 lbs
Handlebars 1lb
Base parts = 10.43 lbs
Measured on my scale this afternoon.
The full build on a V20 is 26lbs and has a roughly a 10lbs disadvantage to the best DF bike. The Bike of the year from 2016 the Trek Madone; in full on race configuration is 15.7lbs and costs $14,500. The V20 is $4500. So that gives you $10k in your pocket to try and close the gap with part selection.
If you want a final setup to be light for a race setup you can shave lbs from on the final build by working the stock parts:
1) Cut down the boom (need calculate the minimum insert for strength given the target length of the boom, no simple math, but not hard),
2) Shorten fork stem; ounces matter
3) cut off the unneeded parts off the headrest pipes
4) Use Carbon handle bars
I think, if you maximize everything you can approach a 2.0-2.5 lbs savings. (Note I'm going to figure it exactly with my current projects)
Then when you pick parts pick the lightest you can afford. Be a weight wennie if you are going to compare to a full on weight wennie bike. Never loose sight of how much those 15lb bikes cost and remember they always lie about the numbers in there favor. aka they don't weight the bike with bar tape; tool bags, water bottle, etc on them. How heavy is your bell and mirrors?
So
1) Use carbon bottle cages
2) Use the lightest components out; that includes things like $250 cassettes.
3) Use the lightest Aero wheels you can find
All said on done you'll be out about $9.5k and you will be down to about 20-21lbs. You'll will still be 5 lbs heavier but you'll have 4-5k in you pocket. So then lose five lbs of body weight and call it good. Jason sorry man your so skinny you just have to train harder.
Just my tips on making the bike light as it stands......
Now since this will then of course lead to chants of "use carbon" lets look at that.
Carbon is going to be 64% the weight of 7005 alloy.... so the simple thought line goes that you have 9.33 lbs in aluminum in the bike. so you should be able hit 6.5 lbs with the frame instead of 10.43 for a total of about 21 lbs on a stock $4.5k build... that would be in a perfect 1 to 1 swap which never happens.
You use carbon differently and the lines change. Carbon leads to curves; alloy leads to pipes and triangles (hydro forming not with-standing). So your not going to get the weight down with a materials change accept to maybe titanium; without some serious redesign, and costs. While I'd sign up for a limited edition Titanium V20 I am not holding my breath... (but keep me on the list)
So back to carbon, the Yellow Vendetta was designed to test the constraints of moving toward carbon in the future hence the huge diameter boom with thin walls and a welded in cut out for the fork stem bracket. Aluminum does not call for that sort of design but, carbon does; as do the hydro formed frame shapes. John T was very open about that back in the day. He was thinking about it as a future iteration.
In the end it is easy to summarize that it apparently did not turn out to look cost effective to go the carbon path. The current designs have instead swung to a focus on equal or better performance and sustainability and viability; and bike sales.
This is total opinion but if you wanted a Carbon V20-C model the following evolution would be necessary and it's going to be expensive:
(1) Develop a carbon back half of the bike; probably in two lengths for different heights (use current front) This gets you a more expensive bike, that is possibly more comfortable on the road but, is barely lighter or maybe heavier. The Hydro-formed 7005 frame section is super light now. At this stage you'd have a higher price but, no noticeable gain. That's not a good business choice. You do this first because "front wheel" aka our back wheels; have a stable non-changing design.
(2) Then follow up with a carbon boom, which would probably look like the old yellow boom to be strong enough; that is an arguable positive gain but, an expensive one. The bike as a result is going to get more fragile. Sliders are notoriously difficult to do in carbon. It hass gotten better in the last few years; CA2 and Encores don't need the giangantic clamp brackets of years gone by on their carbon sliders.
(3) Finally try and develop a carbon fork that can handle the MBB stresses. (Ever look at a home builder threads; they always using exisitng carbon forks because it's darn hard to make a solid carbon fork. Again supper expensive because you are the only one that needs a fork with a 132mm drop out. Lots of setup cost; and finally some gains in total weight reduction. The Problem here is drive wheels are in a heavy state of flux with the move from 130-->135 --> 132 and now 142-145mm through-axle. Getting trapped and having to redesign your carbon forks to keep pace with the bigger industry could be a mess.
If you took it all the way, In the end you are going to have a $6000-80000 framekit before you put parts on it (assume a near zero profit bike for Cruzbike while they pay off the molds). All that to save maybe 4-lbs. Why only 4 lbs, well there is still going to be a lot of metal formed into that carbon; no way the Bottom Bracket is going to be press-fit inside a carbon shell; it is going to have to stay metal wrapped in carbon for the MMB forces to to be handled safety....
End of the day, it is important to remember these are mainstream bikes meant to fit many and varied riders; these are not Zockra one offs at twice the price. (see how well that worked for them?)
Lastly for what it's worth a lot of the potential market for the V20 already complain it's too expensive at 4.5k; the market isn't looking for a V20-C at $9k.... they just aren't. Also ever compare how well a used V20 sells compared to a used Zockra?
Any doubt about why carbon forks are not easy here's you photo proof...
