They're still using the Black Chili, If you can find a 20c it will be the Supersonic. The TT is fastest in a 23 that I've seen tested recently. I think the Supersonic 23 and the TT are more or less the same now. I've not seen a supersonic in a few years though.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

I believe it's the grand Prix TT. Combined rolling / aero test by aerocoach showed the TT to be I think around 2-2.5 Watts faster than a pair of gp5000's at 45kph. The 5000 was more aero but rolled slower. Slower speeds should favor the TT more.

I think the old tread pattern supersonics were faster but good luck finding them....

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Ed O'Malley
www.VeloVetta.com
Founder of VeloVetta Cycling Shoes
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Anyone ridden the 4000RS? I'd never even heard of them until I saw them in a store Saturday. Looked like they were a 25mm version of the 4000 series.

Ok, but are these avail in 20mm? A quick googlefu turned up nothing in that size. And the conti website shows them only in 23 and 25mm. But maybe I missed it?

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Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
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https://www.bicyclerollingresistance.com/...nd-prix-4000-rs-2018

I have them on my training wheels now. They are just like the 4000sii, only available in 25.

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Ed O'Malley
www.VeloVetta.com
Founder of VeloVetta Cycling Shoes
Instagram • Facebook

For 20C you probably have to go with Supersonics if you want lowest crr.

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Ed O'Malley
www.VeloVetta.com
Founder of VeloVetta Cycling Shoes
Instagram • Facebook

+1 I use a 20c SS on my front Hed Jet+ 6 Black. It measures 24mm at 85psi on that rim.

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What's your CdA?

The 20mm SS is it. They don't have a "no holds barred" TT tire in 23mm. The 23mm SS usually measures worse than the GPTT 23 and the 20mm SS. The Attack might be a good TT tire; it is very light (<170g) anyway, but I don't recall any Crr measurements on it.

I have a pair of Supersonics sitting in my closet. They feel so fragile I'm afraid to race them on anything but perfect smooth and clean asphalt.

I raced on them last season and even did a few long rides on them. Great tires, only flat was when I shredded a sidewall and that would have happened to any other tire. Also, if anyone is looking for a 20mm SS, DM me since I have one and it seems like they're hard to find?

I haven’t seen much testing on latex vs tubeless? Anyone have data on that?

I’ve seen claims that latex saves 5.5w per tire but are a pain in the ass to keep pressure in.

When I tested I couldn't measure a difference between 50g latex tube and a 120g latex tube. They were both a lot better than butyl. Some have gotten better numbers with tubeless vs latex, and others no difference.

5W total is reasonable, but not 5W per tire unless you are going 80km/hr.

They're really not that much of a PITA to keep air in. You just have to spend <1 minute topping them up before each ride. Quickly becomes part of the pre-ride routine.

BRR have the 4000RS between the Sii and the TT; they are a lightweight version of the Sii that is, there's basically less rubber on them. I got a pair last month on ebay for a good price, for my training wheels on the TT bike; pleased thus far.

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29 years and counting