Sunday, November 23, 2008

New rolling resistance data

Biketechreview.com has new tire rolling resistance data out this last week which has re-tested tubbies that have been *properly* glued.

Turns out:

[spoiler]The best tubbies are faster than the best clinchers when properly glued.[/spoiler]

Data is here: [url="http://www.biketechreview.com/tires/AFM_tire_crr.htm"]biketechreview.com[/url]

Top 6 least rolling tires: number at the end is watts of resistance per wheel

[spoiler]1 Vittoria EVO Corsa Crono (20) Tubular X 20 11.5
2 Velo Flex Record Tubular X 19 11.6
3 Bontrager Race X Lite Pro Tubular (22) 11.8
4 FMB Silk Tubular (23) Criterium Tread X 24 11.8
5 Vittoria Ultra Speed (20)/Mich Latex tube (18/20) 21 11.9
6 Bontrager Race X Lite Pro (23)/Mich Latex tube (18/20) 23 12.0[/spoiler]

What is properly glued?

[quote][spoiler]It seems now more important to achieve a ~ 100% bond to the base tape - the light gluing I initially used must have allowed some slipping resulting in higher Crr.
The test in 2007 was on a Vittoria Crono mounted on a Sub 9 disc using 3 coats of Mastik 1 glue on the rim and 2 coats on the tire (~ 2 tubes of glue per wheel).
The tire tested out at a very low Crr, significantly lower than the first test with light Continental gluing. I have repeated the test on several Cronos with similar results.
Additionally I have tested other tires with "the same" gluing processes and have seen similar and better results as compared to the light gluing tests.
Rev 8 adds those results plus identifies the glue process. I would estimate that the Crr lightly glued tires might improve by ~ 0.0003 - 0.0004 when properly glued.
Definitions - Properly glued => Mastik 1 - 3 coats on Rim, 2 coats on Tire Lightly Glued => Continental - 2 coats on Rim, no glue on tire
Note on Definitions - in some cases I've tested tires supplied on others wheels and glued by shops - I've identified those cases as Properly Glued.[/spoiler][/quote]

There ya go - no excuses in Adelaide!

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