Short answer: "good" tires (the two you mentioned qualify) with latex tubes at the appropriate pressure in the appropriate width for your wheelset will yield the fastest results.

In general, narrower is better. As are slightly oval shapes and higher thread counts (again, both tires you mention have these).

depends on how fast youre going. when in doubt stick with lower crr

so in latest triathlete mag they conclude:

wider is better: 25 is better than 23 or 21

lower thread counts are better

they do agree latex is better...

i personally think 23 corvo or tangente clinchers with hq latex tubes is the way to go...

---

Randy Christofferson(http://www.rcmioga.blogspot.com

Insert Doubt. Erase Hope. Crush Dreams.

Is that a typo? I thought higher thread count- more supple tires- were faster.

---

Suffer Well.

I'd love to see that. Is it available online somewhere? Is "the latest" issue the swimsuit one?

---

---

"100% of the people who confuse correlation and causation end up dying."

latest issue--swimsuit

---

Randy Christofferson(http://www.rcmioga.blogspot.com

Insert Doubt. Erase Hope. Crush Dreams.

they conclude that wider is better but not for any good reason.

---

---

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Aero isn't always better. A slight advantage in aero can be offset by a big advantage in Crr, comfort , durability, etc..

That said I think the only proven aero benefit of most tires is narrow and the aerowings. Even the narrow wings seems dependant on the rim. Filling the gap with caulk or sealant is possible on any7 tire.

The dimples seem somewhat dubious and the oval profile is also likely dependent on the rim width and tire wear.

In general I'd go for a narrow, low Crr tire. Those traits seem pretty universally good.

Styrrell

---

Styrrell

I took at look at the article. I have a hard time reconciling the info in the article about moderate thread count tires being better than high thread count tires with the AFM rolling resistance chart.

As I recall the Specialized Mondo Open Tubular, with latex tubes, was the best clincher with the Bontrager Race X and R4, Veloflex Record, and Vittoria Corsa being near the top as well.

Perhaps it is just an intreptation of "moderate thread count," but those tires have 290TPI for the Specialized, 220TPI for both Bontragers, 350 TPI for the Veloflex and 320 for the Vittoria. I would consider 290 and above to be a very high TPI, 220 to be a high TPI, between 100 and 200 to be a moderate TPI and below 100 to be a low.

I thought the higher TPI tires, like the latex tubes, reduced rolling resistance because of the suppleness. Thoughts?

---

Suffer Well.

I haven't read the article, but considering the source they are probably giving quite a bit of weight to robustness and comfort over all out speed.

When you are looking for fast tires, pay particular attentionb to width as measured. The Bontrager is low Crr but just a touch wider than optimal. Not sure if they are going to make a narrower version.

Styrrell

---

Styrrell

I agree with you. I thought the aticle was at best unsupported and misrepresentative....

---

Randy Christofferson(http://www.rcmioga.blogspot.com

Insert Doubt. Erase Hope. Crush Dreams.

why even worry about any threadcount trends?
just look at the afm chart. if the tire is made of cement but tests fast, it is fast =)

---

---

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

as I understand it the wings actually aren't proven to do anything, though it certainly looks like they would on some wheels.

it is supposedly the shape of the casing on the bontrager aero tires, and zipp tangente tires, that makes the aero difference.

---

---

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

The article is based upon a test... however no data shown just trends discussed and conclustions drawn. Next month they will have an article with the imporatance and impact of rim weight on speed with an equal amount of data.

---

Suffer Well.

I have some race data from 4 races that are telling me that the Bontrager Aero TT (23) is a better tire for me than the Vittoria Corsa CX (20) on my Hed Jet wheels (650's)

A little later this year I'll have some more comparisons when I repeat some races. Data would be available later today (when I get home) if anyone is interested.

so...no data again? lol

awesome

will be good for my odds in cat4 races

---

---

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Gee, they could even include tire weight and recommend Tufos...

I'm pretty sure this is consistent with what HED would tell you - specifically that it's the transition from tire to rim, and so matching tire width to their C2 rim width is the key variable.

I'm interested in what you find out later this year. jordan.witmer@gmail.com.

---

Running is a gift.

narrow tires are usually still faster on hed's wide rims.

its just that wide tires aren't as MUCH slower.

difficult subtlety for people to grasp...oh well!


either way the bontrager R4 (which is 22 I think) might be faster than various narrower options due to its shape.

---

---

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

is that even allowed in the rules? what would you use to fill the gap?
i sense some testing coming RChung's way.....

---

---

"...I try not to ever ride as slow as 20mph. ;) ... And even more than that, I don't race with a speedometer. My computer is set up to show Power // Cadence // Time. I don't actually ever know how fast I'm going. I only know that if I'm in 53/11, and it takes more than 100rpm to hit my target watts, it's time to coast." - Jordan Rapp on '09 IMC

IIRC is there not an 'aero' tire that is near the top of the Crr list as well?

http://forum.slowtwitch.com/...rch_string=;#1778158

I use RTV sealant. Yes its always been allowed, or at least I'm not the first and I've never hear it being disallowed.

Styrrell

---

Styrrell