|   coefficient of rolling resistance | heatstroke
Oct 21, 2003 10:03 AM | | I saw someone write that a german mag had tested tubeless and come up with a 13 watt savings.
Does anyone have the link ? or a table of rolling resistance numbers for MTB tyres ?
I can find plenty of info on road tyres but none on MTB tyres.
Thanks |
| I would imagine that rolling resistance means a lot when | clary.
Oct 21, 2003 10:40 AM | | road tires are rolling on pavement (bitumen, sealed, asphalted) but why would MTB tires require rolling resistance numbers when they are used in a multitude of surfaces and environments like mud, rock gardens, peat bogs, sand? Shouldn't a rider just try to match tires to conditions and the tire weight and size required? |
| Bad tires can sap 10% of your power, even on dirt | Chester
Oct 21, 2003 5:17 PM | | Two different tires with equally good characteristics in terms of weight and grip/traction under various conditions, can still have very different amounts of rolling resistance. Over a cross country course it cold make a difference of easily 1-5%....which is huge.
To put it another way, if you put out a steady 200 watts of power and you have tires which take an extra 20 watts, per set, of rolling resistance, you have just thrown away 10% of your power....on dirt.
It steals your power with every rotation of the tire. It sounds like your idea is that rolling resistance only comes from the tread/surface interaction rather from tire deformation as it rotates. |
| Actually, I saved that info... | Zignzag
Oct 21, 2003 11:52 AM | | german "BIKE" magazine did a comparison test.they measured just about everything possible:weight,sizes of carcass+tread,size,rolling resistance,protection against pinchflats,price...and for sure on the trail tests.here`s some interesting results:
first of all some rolling resistance measures of different tubes.measured with the same tire and the same pression:
Continental Latex: 140g - 16.3 watts
Schwalbe Standard: 180g - 18.1 watts
Schwalbe Extraleicht: 96g - 18.3 watts
Schwalbe Leicht: 127g - 19.1 watts
Examples of different tire pressures on a Continental Twister Supersonic:
4 bar / 58 psi: 18.3 watts
2 bar / 29 psi: 24.6 watts
Rolling resistance on all those tires was measured with 2.5 bar / 36 psi pression.
"RACE" Tires:
Continental Twister Supersonic: 1.9" - 330g - 21.9 watts
Continental Escape Pro : 2.1" - 511g - 28.6 watts
Hutchinson Scorpion Air Light : 2.0" - 552g - 35.9 watts
Kenda Klimax Lite 345g : 1.95" - 315g - 28.4 watts
Michelin Wildgripper Comp S Light : 2.0" - 456g - 25.7 watts
Nokian Boazbeana X : 1.9" - 426g - 25.7 watts
Maxxis High Roller R : 2.0" - 452g - 28.3 watts
Schwalbe Fast Fred QC : 2.0" - 349g - 18.1 watts
Schwalbe Little Albert Light QC : 2.1" - 490g - 26.3 watts
"ENDURO" Tires:
Continental Explorer Pro Tection: 2.1" - 517g - 29.5 watts
Continental Vertical Pro Tection: 2.3" - 624g - 29.4 watts
Continental Survival Pro Tection: 2.3" - 686g - 32.6 watts
Geax Blade 200. 2.0" - 573g - 34.1 watts
Geax Sturdy: 2.25" - 860g - 30.4 watts
Hutchinson Mosquito Air: 2.3" - 597g - 35.5 watts
IRC Serac XC: 2.1" - 574g - 26.8 watts
Maxxis Harddrive 2.1: 2.1" - 537g - 34.3 watts
WTB Mutano Raptor: 2.24" - 778g - 43.5 watts
Maxxis Ignitor / Dynomite: 2.3"/2.35" - 693g/675g - 37.6/36.9 watts
Michelin Wildgripper FrontS / XL S: 2.1" - 554g - 25.5/24.5 watts
Michelin Wildgripper Hot S: 2.1" - 681g - 36.7 watts
Specialized Roll X: 2.0" - 554g - 43.5 watts
Specialized Enduro Pro: 2.2" - 546g - 31.8 watts
Nokian NBX 2.1: 2.1" - 595g - 28.3 watts
Ritchey Z-Max Millenium: 2.35" - 691g - 26.2 watts
Schwalbe Little Albert Light FO / ORC: 2.1" - 504g - 38.2/30.6 watts
Schwalbe Fat Albert Light: 2.35" - 680g - 31.9 watts |
| do you know the test parameters. | heatstroke
Oct 21, 2003 6:40 PM | | If you can supply a bit more info I can back calculate the coeff of rolling resistance :
How much down force or weight on each wheel ?
What was the speed ?
Thanks |
| Here is what I think you want | Chester
Oct 22, 2003 12:45 AM | | I gave you a link on the other board to the data listed in this thread and also another link (in German) which explains the imput you need...speed and load.
nino "I just had a big laugh when going through MBA..." 7/27/03 1:28am
And some discussion we had about this in an earlier thread
Boj "AnalyticCycling.com, watts, speed, and rolling resistance" 8/31/03 12:27am
Now I must add that while I believe the data you saw in the post above (in this thread) was also done by "Bike" magazine, I am not 100% certain. So I cannot be certain that the data is also using the same imput regarding load and speed.
http://forums13.consumerreview.com/crforum?13@59.guNwa573tAI^21@.ef6a2fc/0
Even though these two testings of different sets of tires takes place at different times, I think they are both "Bike" magazine and while it is difficult to see the same tire in both tests, some are there and test very close... Like the Roll-X Pro which is virtually the same in both sets of data. 43.8 and 43.5 watts...
Also the Conti Twister Supersonic at 21.8 and 21.9 watts
So I think it was the same test procedure in the same magazine but at different times. |
| thanks - just what I was after. nm | heatstroke
Oct 22, 2003 4:53 AM | | |
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