Nice bike! Have you got your wheels yet?

Generally Continental GPTT or Attack are quite fast with good survivability. Definitely use latex tubes... just figure out how to do it right. I have over 50k miles on them and it isn't that tricky.

The TT flat was on a nasty section of road where I have had several flats before. Very wide shoulder with lots of road trash. The hole looked pretty small and it did take couple of minutes for it to get flat. A wire, torn, something small caused the problem.

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BoulderCyclingCoach.com

Continentals are my favourite.
If you can, bump up to a 25mm tyre.

I beg to differ...

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http://bikeblather.blogspot.com/

A 25mm GP TT will be an extremely tight fit for the rear of the Speed Concept when mounted on most modern rims. The 23mm GP TT plumps out to ~26mm on Hed Jet+ rims. I recommend getting the UCI rear brake cover as it makes wheel changes much easier.

No I haven't bought wheels yet, just the stock Bontrager ones it came with. That was going to be another thread :)
I see someone mentioned the rear brake covers and wheel changes. Man this new bike makes it hard to work on things sometimes. I'm absolutely no wrench, but everything is finicky compared to my older bike(reminds me of my old man and our older cars vs new computerized engines). Oh, BTW i was told this is already UCI legal!!!?

Yeah the original post was just to say that i have run across all sorts of opinions on this, although rolling resistance seems to be the top determinant by posters (if durable).

I'm just saying that relatively low Crr isn't always at the expense of the other 2 factors...nor does it need to be.

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http://bikeblather.blogspot.com/

Agree here, Running latex with sealant for the past 4 years and I'm always amazed how many cuts I have in my tire and how many cuts the sealant has done it's job on in the tubes. My buddies who ride TLR's seems to have a lot more trouble. $0.02

I'm quite certain the new bikes ship with the UCI legal basebar and fork.

The old illegal fork is now legal. Did the UCI nix the 3:1 requirement on basebars?

I'm pretty sure Trek just ships the 3:1 fork and basebar now. Not a significant aero difference between the two anyways.

Ideal tire will vary a bit depending on the wheels. Generally it's best to use the biggest one you can fit on the rear (up to a 25mm) and a smaller one on the front... unless your wheel is specifically optimized for a 25mm.

What events? You mentioned UCI so are you doing TTs?

They don't get talked about much, but the Michelin Pro Competition is one of the fast but not crazy fragile tires. In the same realm as the GPTT and Attack but with a little thicker tread. The 23s at least run smaller than the Conti 23s. Don't know about the 25s. The Continental Supersonics should be Conti's fastest tires, and the 20mm is still great, but for some reason the 23 is no better and maybe slightly worse than the GPTT.

Tufos are extremely slow tires. With new equipment you may very well end up faster than ever on less power.

I just got back into mtbiking after 15 yrs also..and tubeless w/ sealants are amazing!!! My entire tire is pocked w/ liquid ooze. I don't race mtb but wonder if racing TT etc, does the sealant add significant weight or not really a consideration at all?

Not really a worry for steady state racing like in TT's as the weight impacts acceleration vs speed maintenance (actually better with a heavier wheel - conservation of momentum). Even with "jerky" racing, speed up slow down over and over, not sure how much it matters.

I did one 20 mile TT and you are right, faster and was in worse shape..excited about new toy!
I will be doing sprint tris, maybe one Olympic, some other solo TT's 15-40 K in distance. At least plans for this year so far.

Thanks for info..esp like wider in back, narrower up front. Whole new world c/w early 2000's.

Ok, gotcha. Makes sense- it seems like a lot when you are putting in a 29er but I've replaced tire and it's considerably less volume, more of a sticky mess that is well distributed. Even less impressive in 25mm.
And once you are rolling it's just momentum.

I've posted before that I do a downhill TT as well as a few up/down races (5miles each way). Tips on the downhill only race? Eat an especially big breakfast? :)

That's basically the way you win pinewood derby races. Heavy as possible with the lowest friction. But they are all equalized by gravity doing the work, not your legs. 😁

To be honest, MOSTLY downhill. About 3000 ft loss in 20 miles with most lost in first 15 miles then flattish to mild up/downgrade (1% or less). One uphill of half mile maybe 4%.

just to throw a consideration on aero optimization here
the best for minimizing aero drag is
GP TT rear 25mm
GP4000 front 23mm

GP TT front are creating aero drag because it doesn't have any pattern to let the air flow.
This is demonstrated in wind tunnel

Yeah it makes it difficult to know what direction to go in. I've run GP4000s on my road and TT bikes for the last 4 years and I think I've punctured twice (in training). Maybe twice, definitely once.