BikeTechReview.com

  • Increase font size
  • Default font size
  • Decrease font size
Home Forum
Welcome, Guest
Username Password: Remember me

Still another Crr-test from a German Magazine
(1 viewing) (1) Guest
  • Page:
  • 1

TOPIC: Still another Crr-test from a German Magazine

Still another Crr-test from a German Magazine 8 years, 2 months ago #25445

  • A Finn
  • OFFLINE
  • Expert Boarder
  • Posts: 118
  • Karma: 0
Still another Crr-test from a German Magazine, this time the "infamous" Triathlon Magazin: #76 / Oct-Dec 2009.

Test equipment the same as in a test in August 2008.

Using a novel test-bench by Endless-Sports
Puncture resistance tested with a sharp needle "machine". Results in Nm.

Test results calculated for 85 kg total weight of rider + bike/accessories, wheel speed 35kmh (for everyday triathlonist). Tube used for clinchers: Conti Race Light 28. All clinchers 23mm except Hutchinson = 21mm.

Air pressure / Bars: 8.5 for clinchers, 10.5 for tubulars.


The Results

Clinchers

Rolling Resistance
Michelin Pro 3 Race TS 33.2 W
Vittoria Open Corsa Evo CX 33.5 W
Conti GP 4000 RS 34.3 W
Schwalbe Ultremo R 36.6 W
Hutchinson Atom 42.6 W

Puncture Resistance
Schwalbe Ultremo R 139 Nm
Conti GP 4000 RS 137 Nm
Michelin Pro 3 Race TS 115 Nm
Hutchinson Atom 112 Nm
Vittoria Open Corsa Evo CX 109 Nm

Sew-ups

Rolling Resistance
Vittoria Corsa Evo CX 35.4 W
Gommitalia Platinum 43.4 W
Conti Competition 44.0 W
Hutchinson Carbon Comp 44.5 W
Schwalbe Durano 45.4 W

Puncture Resistance
Conti Competition 144 Nm
Schwalbe Durano 135 Nm
Hutchinson Carbon Comp 117 Nm
Gommitalia Platinum 111 Nm
Vittoria Corsa Evo CX 109 Nm

A side-note from the test: Conti GP 4000 RR-values for 20mm: 36.0 W, for 25mm: 33.1 W

If you're interested in pictures of the RR test-stand AND earlier tests results, please google for: endless sport prufstand -> ~2nd hit will be a PDF-file named Testbericht (in German).

Cheers, and this time the winners were from France & Italy!

A Finn

Re: Still another Crr-test from a German Magazine 8 years, 2 months ago #25447

  • kraig
  • OFFLINE
  • Administrator
  • Posts: 3285
  • Karma: 4
Thanks for pointing these data out!
-kraig

Re: Still another Crr-test from a German Magazine 8 years, 2 months ago #25452

  • tcramer
  • OFFLINE
  • Senior Boarder
  • Posts: 40
  • Karma: 0
Thanks for sharing!

Some comments:
How did they glue the tubulars from Al's testing that is very important?
How many ride at tubular at 10,5 bar if it's not a time trial?
I think the tire mentioned as GP 4000 RS is instead the GP 24 mm, which also fits the weight a lot better.
The Vittoria CX tires seems to be the old 290 TPI since the new version is called CX II

Re: Still another Crr-test from a German Magazine 8 years, 2 months ago #25460

  • djconnel
  • OFFLINE
  • Gold Boarder
  • Posts: 203
  • Karma: 2
That was my thinking: what's the rationale behind running the tubulars higher pressure?

It reminds me of a race report I read from a master's world champion. Solid rider, obviously , but he said he didn't like tubulars because they were so bouncy due to the high pressure. I asked why he didn't just run them lower pressure. He said for some reason he couldn't resist putting more air in tubulars, so he preferred clinchers.

I am also intrigued by the relatively high CRR of the tubulars. It makes me also wonder about gluing technique. These tests are against a planar surface, which should be more realistic than the cylindrical deformation induced by a roller.

Re: Still another Crr-test from a German Magazine 8 years, 2 months ago #25463

  • A Finn
  • OFFLINE
  • Expert Boarder
  • Posts: 118
  • Karma: 0
Comments:

Don't know about the gluing procedure, there is a sub-article inside the main test: "How to fasten tubulars" which is apparently basic information. My latest acquaintance with tubulars dates back in 1986, so I can't comment on this.

They say that the difference in Crr between Kitt = Glue? or Klebeband = Tape? method is insignificant??

The test is really for Kona-distance triathlonists, full 180 kms, solo time trial. They were actually criticized a couple of years ago for testing tubulars and clinchers @ same air pressure, so they changed the procedure!

The Conti (at least in the picture) is GP 4000 RS, the weight is for clincher and inner tube combined.

Both Vittorias in the pictures say ……. CX ….. 320 TPI. It was hard to recognize, had to use 2 x +3 glasses stacked

Cheers

A Finn

Re: Still another Crr-test from a German Magazine 8 years, 2 months ago #25466

  • AFM
  • OFFLINE
  • Platinum Boarder
  • Posts: 538
  • Karma: 4
A Finn wrote:
Comments:

Don't know about the gluing procedure, there is a sub-article inside the main test: "How to fasten tubulars" which is apparently basic information. My latest acquaintance with tubulars dates back in 1986, so I can't comment on this.

They say that the difference in Crr between Kitt = Glue? or Klebeband = Tape? method is insignificant??

The test is really for Kona-distance triathlonists, full 180 kms, solo time trial. They were actually criticized a couple of years ago for testing tubulars and clinchers @ same air pressure, so they changed the procedure!

The Conti (at least in the picture) is GP 4000 RS, the weight is for clincher and inner tube combined.

Both Vittorias in the pictures say ……. CX ….. 320 TPI. It was hard to recognize, had to use 2 x +3 glasses stacked

Cheers

A Finn


Nice to hear from you again Mr. Finn . Hope all is well.

I finally did test the same model of tire properly glued and installed using the Tufo Extreme tape and to my surprize (and possibly many others) found not much difference in Crr as well.

Interesting that they found the Michelin Pro 3 Race with lightweight butyl tube inflated to 125 psig has a Crr less than the Vittoria CX tubular inflated to 155 psig on a smooth surface ?? However no tire sizes given (is the CX a 21 - but even so it should be faster) - maybe more detail in the pdf which I'll have to go through. The assumption has been that the roller tests results (which are actually calculated to give results on the flat using Tom's method) would yield the same ranking on a flat surface based on the thinking that the same tire properties that make a tire fast on the rollers would also make them fast on a flat surface but ???

Re: Still another Crr-test from a German Magazine 8 years, 2 months ago #25467

  • Coolhand
  • OFFLINE
  • Gold Boarder
  • Posts: 251
  • Karma: 1
That was an epic failure of a test, they didn't even correct for tube types (most of the tubs had latex tubes).

Tube used for clinchers: Conti Race Light 28. All clinchers 23mm except Hutchinson = 21mm.
Everything's coming up Milhouse!

Re: Still another Crr-test from a German Magazine 8 years, 2 months ago #25468

  • A Finn
  • OFFLINE
  • Expert Boarder
  • Posts: 118
  • Karma: 0
The PDF is about the earlier tire test (2008). They describe the test apparel there, too.

Can't say about the size of Vittoria tubular tested, in the picture it says: Open (!) Corsa Evo 23-622, so they have conveniently copied the clincher picture! They don't call it the infamous Triathlon Mag for nothing!, but even a bad test is slightly better than no test at all - or is it??

Cheers!

A Finn [Thanks Al, almost all is well now, still (still? :-) ) ) riding]

Re: Still another Crr-test from a German Magazine 8 years, 2 months ago #25469

  • tcramer
  • OFFLINE
  • Senior Boarder
  • Posts: 40
  • Karma: 0
Most of the test performed by German Magazines I have seen, gives the clincher tires the advange when it comes to rolling resistance. I am thinking that it could be down to a bad gluing procedure. Onfortunately they never describe how the tubulars were glued.
  • Page:
  • 1
Time to create page: 0.62 seconds

Poll

Which type of tire is more aerodynamic?