New Crr Data Including MP3L

[AFM]

Thanks to Rob, Ron, and Tom who provided some interesting tires and agreed to share the results.
The MP2L control tire tested in range. As usual the tire pressure was 120 psig. Here are the results corrected to 68 F:


Tire/tube, width (mm), weight (grams), Crr, Notes

Specialized Dual Compound Mondo (23)/Mich latex (18/20), 23.1, 234, 0.00233, New Tire

Continental GP 4000 S (23)/Mich latex (22/23), 24.3, XXX, 0.00286, Very Used Tire (tread squared off)

Kenda Kaliente Light 165 gram (23)/Mich latex (22/23), 23.8, XXX, 0.00301, Used Tire

Michelin P3L SC/Mich latex (22/23), 23.0, 183, 0.00272, New Tire

Michelin P3R 25 SC/Mich latex (22/23), 26.1, 213, 0.00283, New Tire

Michelin P3 Grip 23 SC/Mich latex (22/23), 22.9, 195, 0.00307, New Tire

Continental Super Sonic Grand Prix 20 (Black Chili)/Mich latex (18/20), 19.9, 134, 0.00251, New Tire (center ridge shaved off)


The Mondo is fast - I did have one of the RXL Pro 23 tires down at ~ 0.00235 as well but most were ~ 0.00245. It is very similar to the Bonty version and the Vittoria KS tires I have as well - curious that the Vittoria brand tires are the slowest of the bunch ?? The GP 4000 S did improve with miles (had it at 0.00307 with 200 miles - also may have stretched as I had it before at 23.4 mm - now 24.3 mm wide. The Michelin P3 tires all did well. The P3L came in a bit higher than the P2L possibly because it is much more narrow at a true 23.0 mm - the P2L measures closer to 24.5 mm. The Pro Race 25 just barely fits into the TTX rear wheel cutout. The P3 Grip was surprisingly good - just slightly slower than the first P3 Race that I measured. Probably some errors in day to day variations plus possibly some tire to tire variation ?? Not much mold release on the rollers as well - some but not as much as the P2 series of tires. All the tires are new and so will improve a bit in the first 50 miles or so. The Continental Supersonic was a complete surprise - very light but extremely fast for such a narrow tire. The Kenda Kaliente Light is "out of print."

edit - add info on the Kenda Light tire

[Ron Ruff]

Thanks Al! I guess the Mondo is using a Vittoria casing? Maybe it is a different tread compound?

I just measured the width of my well used GP4000S tires and they are 23.6r and 23.2f. I think these are the most durable and long lasting tires I've owned... and decent Crr too. The tread compound seems to be a big improvement in every way compared to what Conti used before. Based on Conti's info the casing on the GP SS looks like it is the same as the GP4000 only without the puncture belt and obviously very little tread. It won't last long before the tread is gone, but I wonder how fragile it will be for punctures and such...

[AFM]

Thanks Al! I guess the Mondo is using a Vittoria casing? Maybe it is a different tread compound?

The RXL Pro, Mondo, and Open Corsa KS all look very, very similar except for the tread.

I was in Solvang for the TOC TT and of course checked out the team paddocks looking at the tires:

Astana is using the Bonty RXXXL tubular (modeled after the rebadged Hutchinson that very closely resembles the VF Carbon - I saw Lance flat another one yesterday), Columbia and BMC use Continental (which the head BMC mechanic insists are supplied with butyl tubes and don't require latex ??), Bissel uses Vredestein, Ouch uses Maxxis (ouch!! - might be clincher ??), Liquigas uses Schwalbe Stelvio (which I've tested - they don't roll very well and are made by Tufo), and Saxo and Quickstep use Specialized which look a lot like the Bonty RXL Pro . All the other teams I looked at use Vittoria - mix of 290 and 320 tpi. Of course some of these might be rebadged ?? Curious - no Veloflex ?? I didn't see Ag2R however - it almost looked like they are using Michelin clinchers from the TV coverage ?? From Googling it may be that they use Michelin for the road and Continental for the TT's ??

As tcramer noted in another thread Garmin used a Vittoria Corsa Evo CX 23 (320 tpi) on their front wheels (1080/808) but did use the Crono on the disc wheels. IIRC Zipp designed the 808 and 1080 this year. Does anyone know if they are wider ??

[tcramer]

Just saw a picture of one of the Rabobank tt bikes at cyclingnews.com. I am quite sure it has the Vittoria Crono on the front.

The 1080 wheels alwas had a wide bed and thus should be optimized for 23 mm and for 2009 the 808 were redesigned based on the experience zipp gained from designing and testing the 1080. The major change is the wider bed and wider bulge.

[alvarov]

Hi Al,

as always, thanks for sharing...

Is that Specialized the top of the range S-works open tubular?

cheers,

alvaro

[JV]

As always, thanks Al.

I wonder if that 19.9mm Conti will be the new tire of choice for an H3? I'm running the Bonty Race Lite with the wings at the moment, but giving up a good bit of Crr to the Conti. Wonder how valuable those wings really are...

[AFM]

As always, thanks Al.

I wonder if that 19.9mm Conti will be the new tire of choice for an H3? I'm running the Bonty Race Lite with the wings at the moment, but giving up a good bit of Crr to the Conti. Wonder how valuable those wings really are...

I've got some additional and very good Crr data on the Aero Wing TT 19 tire as well - just waiting for some minor clarification from Trek on the size 23 before disclosing. Depending on the weight of your AWTT 19 you aren't giving up much as all. Hopefully will get this out in a few days. My understanding is that Trek will also release some aero data on the tire soon.

[AFM]

Hi Al,

as always, thanks for sharing...

Is that Specialized the top of the range S-works open tubular?

cheers,

alvaro

I'm not positive - have an email in to Tom for clarification. I assumed it was their top of the line open tubular (265 grams) but the weight of the tire I tested is right on the spec for the Clincher model (230 grams) which is the lower priced. Just heard from Tom and it is the Open Tubular which means that it is a lot lighter than spec ??

[triguy42]

Thanks again for your hard work and dedication to rooting out the best (and worst) in tires! I'll be looking eagerly for the 19mm Aerowing data, since I have an H3 that is itching to get replacement rubber from the 20mm Pro2Race it's currently wearing.

Funny aside, I saw this at the bottom when I was reading: "Users browsing this forum: Google [Bot], Google Adsense [Bot], triguy42 and 2 guests"

[AFM]

Actually I'm not doing much in the way of rooting out good tires - more the case of others sending in prospective fast tires which I test for them and they are generous enough to share. These AWTT tires were provided by Tom and Trek. As promised here is the data.

Tire/tube, width (mm), Weight range (g), Crr

Bontrager Aero Wing TT (19)/Mich latex (18/20), 20.0, 176 - 186, ~ 0.00275

This is the average of 3 new tires that I recently tested. Recall that the data in the Crr list was for a tire that I tested over a year ago which came in at 0.00330 new (with an improvement to 0.00311 after ~ 200 miles). Why the difference ?? The original tire I tested weighed 204 grams. The design of the tire has apparently been changed as seen in the reduced weight of the tire and the improvement in the Crr. The measured Crr of each respective tire also tracked it's weight, i.e. the lighter the faster. My understanding is that Trek/Bontrager has also done a lot of wind tunnel testing on the Aero Wing tires showing good results which they plan to release soon. Good result however there may be/are some of the older/heavier tires out there. I just received 2 new ones last week - one weighed 181 grams and the other weighed 194 grams. Haven't test these tires yet but I'm a bit worried about the heavier one . The tire packaging still shows 200 grams.

[triguy42]

Well, I guess 0.311 would be pretty similar to the 20mm Pro2Race that I have on there now (listed at .306) but with possible aero advantages. 0.275 would be a really nice improvement, maybe not as good as an Ultraspeed or Veloflex Record but I'll have to see what kind of aero data they throw out there...

[Ron Ruff]

The measured Crr of each respective tire also tracked it's weight, i.e. the lighter the faster.

Wonder if it is just tread thickness variation. Can you pretty much draw a line through the weight vs Crr plot?

[AFM]

The measured Crr of each respective tire also tracked it's weight, i.e. the lighter the faster.

Wonder if it is just tread thickness variation. Can you pretty much draw a line through the weight vs Crr plot?

It's fairly linear including both the new faster and lighter ones and one of the older and slower ones. For some reason the one that I initially tested had a much higher Crr than the second bought at the same time. I tested that second one after testing the new tires. I don't have any of the tires at this time so can't make any measurements.

[stitchboy]

Al,

Is there any chance you will be testing the new 320 TPI Vittoria in clincher or tubular anytime soon? I have high hopes for this particular tire, hopefully it will be super fast with good puncture resistance. The weight looks fantastic as well. Curious how the new Schwalbe tires are as well.

[Ron Ruff]

I think the way it usually works is:

a) There is a tire you'd like to see tested.
b) You buy it and send it to Al.
c) He tests it when he gets a chance and sends it back to you.

[stitchboy]

Ah...ok got it.

[AFM]

Al,

Is there any chance you will be testing the new 320 TPI Vittoria in clincher or tubular anytime soon? I have high hopes for this particular tire, hopefully it will be super fast with good puncture resistance. The weight looks fantastic as well. Curious how the new Schwalbe tires are as well.

There are some of the Schwalbe clincher tires (Stelvio and Ultremo) in the list - these were tested in 2006. I don't know if these models have been upgraded ?? Also a couple of Stelvio tubulars (made by Tufo). As Ron mentioned, if you would like to send some tires let me know via PM.

[footwerx]

i think the new Ultremo R tyres are slightly different from the original ones.

On another note, i just weighed a new conti GP Supersonic 20mm at 144g which is somewhat heavier than the one tested here
oh well the claimed weight is 150g so i can't complain.

[Ron Ruff]

I just received another 20mm and a 23mm Conti SS... weights were 138g and 155g. I noticed that the casing width of the 23mm SS is noticably less than the 23mm GP4000, so I'm guessing it will be in the 22-22.5mm width range.

[jnovitsky]

Alan-
thanks again for the update.

Here's what might be a silly question: with the low Crr of the very lightweight tires, which are prone to flatting in road TTs, what would the effect be to mount them on your TT race wheels, shoot some sealant into the tubes to prevent flats, and race road TTs with them? For the hour record, some racers choose heavy wheels to act as flywheels. Does anybody have any experience measuring this effect? Any theoretical discussion?

Cheers, JN

[JV]

Here's what might be a silly question: with the low Crr of the very lightweight tires, which are prone to flatting in road TTs, what would the effect be to mount them on your TT race wheels, shoot some sealant into the tubes to prevent flats, and race road TTs with them?

If you search this forum for the term "sealant", you'll see it's come up quite a bit, so apparantly not so silly. I'll let you read the last several years worth of thoughts on the topic, but I'll add one more point that hasn't come up yet. I'm the guy that says sealant in tubes maybe not going to help so much in the case of a puncture on the road (and my experience trying to seal a Vittoria Crono bears that out), and now I also found out the hard way that a latex tube you allow to go flat with (latex based) sealant in it becomes effectively useless due to adhering to itself.

So, there are a couple practical problems using sealant, besides which it might not even really help stop flats.

[AFM]

Here's what might be a silly question: with the low Crr of the very lightweight tires, which are prone to flatting in road TTs, what would the effect be to mount them on your TT race wheels, shoot some sealant into the tubes to prevent flats, and race road TTs with them?

If you search this forum for the term "sealant", you'll see it's come up quite a bit, so apparantly not so silly. I'll let you read the last several years worth of thoughts on the topic, but I'll add one more point that hasn't come up yet. I'm the guy that says sealant in tubes maybe not going to help so much in the case of a puncture on the road (and my experience trying to seal a Vittoria Crono bears that out), and now I also found out the hard way that a latex tube you allow to go flat with (latex based) sealant in it becomes effectively useless due to adhering to itself.

So, there are a couple practical problems using sealant, besides which it might not even really help stop flats.

IIRC the argument and what is seen in practice is that there is so little air volume in a narrow racing tire that by the time the sealant plugs the hole (if it does) the tire pressure is very low. I didn't have sealant in the Crono I flatted in Louisville but I couldn't seal the hole when I returned home either. But actually the Aero Wing 19 feels like a fairly robust tire. It's narrow but weighs ~ 180 grams - feels much more durable than a VF Record clincher tire (~ 140 grams). I've heard of tires with several hundred miles on them.

[JV]

[But actually the Aero Wing 19 feels like a fairly robust tire. It's narrow but weighs ~ 180 grams - feels much more durable than a VF Record clincher tire (~ 140 grams). I've heard of tires with several hundred miles on them.

Mine's got at least 300, and shows no signs of wear. I'll also second the "robust tire" appearance on the Aero Wing 19. That's especially a benefit for me, as the NM roads are often strewn with goatheads, broken glass, and other debris.

[jnovitsky]

Thanks guys; makes sense.

Here's another silly idea: for some of the clinchers that have great Crr, why not trim a "Mr Tuffy" strip to fit? It'd make the tire "harder" as well, and theoretically roll more easily, in addition to becoming virtually puncture proof. Any thoughts, or data/experience? (I'm thinking hard about this, because I saw Jens Heycke flat in front of me on both tires at NCNCA district tt in '07, and saw Alan Morrison roll/hobble in on a flat tire at nationals tt '08. Bad things sometimes happen to really good people.)

For anybody in materials science, why not try to make a "run flat" racing tire filled with a very lightweight foam that hardens? Say you glue it on to the rim, then fill it with the foam after it's mounted? You could probably engineer the material to have compliance comparable to say a tubular filled up to 150lbs, and with a decent rubber external wrapper, it'd handle fine on non technical tt's. If you want the tire to be really hard, engineer the foam to adhere/bond to the tube. If you want it to be softer, engineer the foam to form it's matrix, but not to adhere/bond to the tube. (The long tt at this year's Giro would be the worst case for using such a tire.) It might gradually break down over time, but if it lasts for a few hundred miles at a very low Crr with no chance of a flat, many of us would pay good money for it, to eliminate one source of variability/failure in races.

cheers, JN

[Coolhand]

JN,

Most of those options would probably lead to a horrible handling/crr situation (aka the "Tufo Effect" ).

If flats are a concern, it seem to make more sense just selecting a less fragile tire which also scores relatives well on puncture like the ProRace 3's (not the light version). To me outside of a Velodrom, you should never run a tire without a breaker belt. As fun as the Supersonic (it was like a slipper it was so soft and flexible) and PR3Light would be from a CRR standpoint they are just too fragile for most uses.

You need to finish to win. Even with a wheel van, a flat will probably end your chances in most races.

IMHO, as always.