curious if anyone concurred with mba's recent tire reviews or not. specifically looking for comments on specialized roll x pro's as they're one of few on list i haven't tried as yet. looking for durable 'scrabble over hardpack/loose rocky terrain' tire that works well in central texas hill country. any good one's NOT make the list?
roll x pros and balance of mba tire reviews?
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Roll X Pros are one of the worst tires around
Reviews and real scientific testing are two different things...
Make a search of "roll x" and "rolling resistance"
Over on the Save Some Weight board there have been many threads that included discussion about Roll X Pros......
All the commentary was poor to bad....
They are slower than a slug....... Their rolling resistance numbers on the more scientific tests from the Germans are simply terrible...
If you don't mind having to pedal much harder, and going slower, then I guess their grip is OK......But they are DOGS when it comes to speed or ease of rolling....
I don't care what Specialized says in the ads.....they really slow you down.
My 03 Stumpy came with a set, and I took them off after a few weeks.....
Put on another set of tires and was much faster......MUCH faster..
And its not just my example........the scientific testing confirms the same....
They such the juice out of you in terms of more watts of power required to push them down the road......lots more power wasted....
Don't buy them.......I wouldn't ride them even if I could get a endless supply for free.
So unless they've changed something since the 03 models were sold, I'd avoid them at all costs.......
What else did they list as good in the reviews?
You should really get one that has been tested and shown to have a fairly low watts rating but still gives you the grip and wear you want.
I didn't read the review, but you can't believe everything you read in the mags, when that mag makes their money off of advertising revenue.from the same company..bbneu said:
Reviews and real scientific testing are two different things...
Make a search of "roll x" and "rolling resistance"
Over on the Save Some Weight board there have been many threads that included discussion about Roll X Pros......
All the commentary was poor to bad....
They are slower than a slug....... Their rolling resistance numbers on the more scientific tests from the Germans are simply terrible...
If you don't mind having to pedal much harder, and going slower, then I guess their grip is OK......But they are DOGS when it comes to speed or ease of rolling....
I don't care what Specialized says in the ads.....they really slow you down.
My 03 Stumpy came with a set, and I took them off after a few weeks.....
Put on another set of tires and was much faster......MUCH faster..
And its not just my example........the scientific testing confirms the same....
They such the juice out of you in terms of more watts of power required to push them down the road......lots more power wasted....
Don't buy them.......I wouldn't ride them even if I could get a endless supply for free.
So unless they've changed something since the 03 models were sold, I'd avoid them at all costs.......
What else did they list as good in the reviews?
You should really get one that has been tested and shown to have a fairly low watts rating but still gives you the grip and wear you want.
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196 Posts
Yeah - there have been a couple of threads about this article. MBA likes the Roll-X Pros, along with several tires from Kenda (Karma, Nevegal). They gave the Python Lites and the Nokian NBX 2.0 poor reviews. Not sure why.
I have owned Roll-X, Pythons, and NBX tires. The Roll-X tires are slightly slower rolling than the others. My scientific testing involved coasting down paved hills with a friend and getting dropped. They are pretty good at everything else, and would make nice training tires. I may try a pair of the Kenda Karma DTC tires when my Nokians wear out (which will be real soon - these things don't last).
I have owned Roll-X, Pythons, and NBX tires. The Roll-X tires are slightly slower rolling than the others. My scientific testing involved coasting down paved hills with a friend and getting dropped. They are pretty good at everything else, and would make nice training tires. I may try a pair of the Kenda Karma DTC tires when my Nokians wear out (which will be real soon - these things don't last).
Slightly slower?
Do you mean 1% or 2% or 5%.......?
If I'm making a 20 minute climb and and the tire is 3% faster, thats 36 seconds which may equal over a football field in lenght........Thats like leaving the other guy in the dust, big time..... In a race thats a huge win...
What do you mean when you say that Roll-X Pros are "slightly slower rolling" ?craig said:
Do you mean 1% or 2% or 5%.......?
If I'm making a 20 minute climb and and the tire is 3% faster, thats 36 seconds which may equal over a football field in lenght........Thats like leaving the other guy in the dust, big time..... In a race thats a huge win...
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196 Posts
Since I don't have any testing equipment, and the only scientific results I have seen have been posted many times, I just gave my impressions. On a 1/4 mile downhill with the Roll-X, I lost about 30-40 ft while coasting against someone with Pythons.
I am definitely not endorsing the Roll-X tires - especially not for racing. If they are free (came on my bike), they make a decent pair of training tires.
Yeah - I went back and looked at that issue and the only tire makers with full page ads were Specialized, Kenda, and Intense. Oh well...
Take a look at this.......analysis
Now, 3% if HUGE........Let me give you an example looking at it in a different way...
I have a hill near me that is a 1.37 miles fire trail climb.... elevation gained is approx 580 feet. It takes me, all out, amost exactly 10 minutes (600 sec). A killer pace for someone my age....
Anyway......3% on that climb would equal 18 seconds.....
Some folks don't think that a tire giving you an extra 3% is all that big a deal....
But they think nothing of spending $1,000 to make their bike lighter....
According to the calculator on annalyticcycling.com, going up that same hill and trying to cut off that same 18 seconds would require me to drop 5.35 pounds off my bike..
Imagine that.......over FIVE pounds off the bike is needed to equal the benefit of that Nokian tire going up that hill.....
Thats like taking a 27 pound HT versus a sub-22 pound HT.......
Everyone would think that was a big deal.......but when you say a simple tire change will do the same thing......there is disbelief by most riders...
Also.......Very interesting that you looked at the magazine advertisers in that specific issue. They are shameless in promoting their advertisers.....
You can't believe what they print..
Good stuff that you found that.
40 feet on a quarter mile is .... 40 feet divided by 1320 feet or almost exactly 3%craig said:
Now, 3% if HUGE........Let me give you an example looking at it in a different way...
I have a hill near me that is a 1.37 miles fire trail climb.... elevation gained is approx 580 feet. It takes me, all out, amost exactly 10 minutes (600 sec). A killer pace for someone my age....
Anyway......3% on that climb would equal 18 seconds.....
Some folks don't think that a tire giving you an extra 3% is all that big a deal....
But they think nothing of spending $1,000 to make their bike lighter....
According to the calculator on annalyticcycling.com, going up that same hill and trying to cut off that same 18 seconds would require me to drop 5.35 pounds off my bike..
Imagine that.......over FIVE pounds off the bike is needed to equal the benefit of that Nokian tire going up that hill.....
Thats like taking a 27 pound HT versus a sub-22 pound HT.......
Everyone would think that was a big deal.......but when you say a simple tire change will do the same thing......there is disbelief by most riders...
Also.......Very interesting that you looked at the magazine advertisers in that specific issue. They are shameless in promoting their advertisers.....
You can't believe what they print..
Good stuff that you found that.
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1,377 Posts
Try a Schwalbe Big Jim or Fat Albert. The big jim is a faster roller but the albert has more traction, just make sure and get at least a 2.25. Kenda Blue Grooves are real good too for Texas conditions. Hutch pythons arent good for Texas, they dont last very long. 2-3 months is not very long to me anyways.bbneu said:
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202 Posts
in defense of MBA
That is a good point about the 3%, and about rolling resistance in general
But seriously, do you guys really think this shootout was determined by advertising? Yes, K.enda and S.pecialized had full-page ads, and finished 1-2, but so did M.axxis, I.ntense, and A.zonic (a FR tire ad on the back cover), and only one of those 3 broke the top 10. I mean hey, why isn't A.zonic in 1st, since their ad cost the most, right? and A.zonic and I.ntense at least deserve top-10 finishes, right? Sorry, I don't think we can write off the test that easily. We can't claim to know exactly how this works; it's an editorial test; it relies on the subjective opinions of a group of people, like us. It's fair to wonder how exactly ad revenue influences editorial decisions, but we don't have any direct evidence, at least in this thread, and the article itself doesn't follow the logic. I'm just saying that the 'ads=good reviews' doesn't always fit in MBA. Here's another example: R.ST takes out full page ads practically every month-- why isn't MBA telling us all to ride their forks? And so on, there are other such examples. What we probably CAN say with some surety about MBA is that they like S.pecialized and K.enda, in general, and that seems to be reflected in the test. But that shouldn't be much of a surprise to MBA readers.
That is a good point about the 3%, and about rolling resistance in general
But seriously, do you guys really think this shootout was determined by advertising? Yes, K.enda and S.pecialized had full-page ads, and finished 1-2, but so did M.axxis, I.ntense, and A.zonic (a FR tire ad on the back cover), and only one of those 3 broke the top 10. I mean hey, why isn't A.zonic in 1st, since their ad cost the most, right? and A.zonic and I.ntense at least deserve top-10 finishes, right? Sorry, I don't think we can write off the test that easily. We can't claim to know exactly how this works; it's an editorial test; it relies on the subjective opinions of a group of people, like us. It's fair to wonder how exactly ad revenue influences editorial decisions, but we don't have any direct evidence, at least in this thread, and the article itself doesn't follow the logic. I'm just saying that the 'ads=good reviews' doesn't always fit in MBA. Here's another example: R.ST takes out full page ads practically every month-- why isn't MBA telling us all to ride their forks? And so on, there are other such examples. What we probably CAN say with some surety about MBA is that they like S.pecialized and K.enda, in general, and that seems to be reflected in the test. But that shouldn't be much of a surprise to MBA readers.
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155 Posts
Pros & Cons to both...
I think there are pro's and con's to both scientific and editorial reviews.
Scientific tire tests are made in a laboratory setting, with certain fixed environment variables (controls), so that all of the compared tires are compared in the identical conditions. These controls give a honest comparison between the tires, BUT are only really valid when the environment exactly matches the controlled environment that the tests took place in. I don't know what surface they use for testing, but I would guess it is a smooth hard surface. I ride big knobby sticky Kenda Kenetics 2.35's, on the road it feels like I'm dragging a body behind me, but on dirt, they roll much faster. I don't think a 3% rolling resistance difference in scientific conditions (assuming they are testing on a hard smooth surface) will be exactly the same in all trail conditions.
Editorial reviews, while they can be biased, are usually based on real world experience of the tires, where they face the multitude of variables that make a tire good (or not good) in real world circumstances. There is the possibility tires will not be tested on equal terms (i.e. Tire A was tested after a rain storm while Tire B was tested in blistering hot dry conditions) but I think having many testers doing many tests over a long period of time would mitigate these inconsistencies.
I also disagree with the analysis that 3% difference in tire rolling resistance will directly translate into 3% faster climb or race time (off road that is). There are just too many other variables. If that where the case, every XC racer would be riding hard rubber slick's...but other factors such as rear tire traction, braking bite, cornering traction, etc. all have a BIG effect on the overall performance. i.e. On a climb you could run the lowest resistance tire in the world, but if you are losing 1/16'th of a spin of the rear wheel every pedal stroke due to poor traction, you are not going to get that 3% gain from rolling resistance, compared to an equal rider with slower rolling tires, who loses less traction on each pedal stroke.
I read the MBA tire review today at lunch, while there may have been some brand bias (I don't really see it though, there where high and low rated tires from most of the brands, the top two may be suspect?) deffiantly the biggest bias is towards dry south-west riding conditions. They never took into consideration performance in wet, muddy, slippery conditions...making the review less relevant to me, riding in the North-West, where wet riding performance is always a consideration!
You have to take any published review with a grain of salt. Read the review, apply some common sense, your own past experiences, see what has and has not worked for others riding the same trails as you, and make an informed buying decision on your next set of tires. Or, you could always use the trial and error method of finding the best tire for you...but I learned that can get pricy, and sometimes painful. ;-)
sh0rty
I think there are pro's and con's to both scientific and editorial reviews.
Scientific tire tests are made in a laboratory setting, with certain fixed environment variables (controls), so that all of the compared tires are compared in the identical conditions. These controls give a honest comparison between the tires, BUT are only really valid when the environment exactly matches the controlled environment that the tests took place in. I don't know what surface they use for testing, but I would guess it is a smooth hard surface. I ride big knobby sticky Kenda Kenetics 2.35's, on the road it feels like I'm dragging a body behind me, but on dirt, they roll much faster. I don't think a 3% rolling resistance difference in scientific conditions (assuming they are testing on a hard smooth surface) will be exactly the same in all trail conditions.
Editorial reviews, while they can be biased, are usually based on real world experience of the tires, where they face the multitude of variables that make a tire good (or not good) in real world circumstances. There is the possibility tires will not be tested on equal terms (i.e. Tire A was tested after a rain storm while Tire B was tested in blistering hot dry conditions) but I think having many testers doing many tests over a long period of time would mitigate these inconsistencies.
I also disagree with the analysis that 3% difference in tire rolling resistance will directly translate into 3% faster climb or race time (off road that is). There are just too many other variables. If that where the case, every XC racer would be riding hard rubber slick's...but other factors such as rear tire traction, braking bite, cornering traction, etc. all have a BIG effect on the overall performance. i.e. On a climb you could run the lowest resistance tire in the world, but if you are losing 1/16'th of a spin of the rear wheel every pedal stroke due to poor traction, you are not going to get that 3% gain from rolling resistance, compared to an equal rider with slower rolling tires, who loses less traction on each pedal stroke.
I read the MBA tire review today at lunch, while there may have been some brand bias (I don't really see it though, there where high and low rated tires from most of the brands, the top two may be suspect?) deffiantly the biggest bias is towards dry south-west riding conditions. They never took into consideration performance in wet, muddy, slippery conditions...making the review less relevant to me, riding in the North-West, where wet riding performance is always a consideration!
You have to take any published review with a grain of salt. Read the review, apply some common sense, your own past experiences, see what has and has not worked for others riding the same trails as you, and make an informed buying decision on your next set of tires. Or, you could always use the trial and error method of finding the best tire for you...but I learned that can get pricy, and sometimes painful. ;-)
sh0rty
Common sense is commonly wrong
This point is always brought up. Common sense would tell you this.......but common sense would be wrong...
The tire with faster rolling resistance will consistantly roll faster.......both on the street and on the dirt.
I think I could make an exception to this in unusual conditions as follows.
Suppose you had a 1.25 ATB slick and were trying to ride it through some deep sandy soil......In that case perhaps the Kenetics 2.35's might allow you to float along the surface and actually be faster......but that is a rare occurance and an extreme comparison....a 1.25 slick versus a 2.35 knobby...
"I also disagree with the analysis that 3% difference in tire rolling resistance will directly translate into 3% faster climb or race time (off road that is). There are just too many other variables. If that where the case, every XC racer would be riding hard rubber slick's...but other factors such as rear tire traction, braking bite, cornering traction, etc. all have a BIG effect on the overall performance. i.e. On a climb you could run the lowest resistance tire in the world, but if you are losing 1/16'th of a spin of the rear wheel every pedal stroke due to poor traction, you are not going to get that 3% gain from rolling resistance, compared to an equal rider with slower rolling tires, who loses less traction on each pedal stroke."
Now in this case YOU are the one picking out the most unusual situation to try to make your common sense seem reasonable...
XC racers would of course never use hard rubber slicks........so lets dismiss this example.
On the other hand they might pick the best rolling resistance knobby which still gave them adequate traction....or they might even compromise a bit of traction on short sections of very steep climbs in order to gain huge advantages in all other sections..
After all the final finish line time is all that matters.....If he loses 3 seconds on one climb but gains 23 seconds on the next section, then he is still 20 seconds better off.
You put on a fresh set of Nokians and you are not going to be having your tires spinning out on every stroke of the pedals... In fact you may find they grip exactly the same as your much slower tires with larger knobs.
I think you may be making the all too common mistake of thinking that a tire with very small and shallow tread is the tire with the lowest rolling resistance.......or that lack of knobbies is the key feature affecting rolling resistance. This just isn't the case.
Low rolling resistance has a lot more to due with the tire construction than just having a smooth tread. Thats why the Nokian works so well. Grips well and rolls welll.
You want to get around a cross country course faster......to the finish line....
Get a tire with very low rolling resistance, but with just enough grip.
On the other hand if you are just out for recreational rides and time is of little consequence then take any tire that you like. Just don't make believe that over an entire course it will be faster. Faster on some particular section.....perhaps, but you will pay for it later on the course.
"I ride big knobby sticky Kenda Kenetics 2.35's, on the road it feels like I'm dragging a body behind me, but on dirt, they roll much faster. I don't think a 3% rolling resistance difference in scientific conditions (assuming they are testing on a hard smooth surface) will be exactly the same in all trail conditions."sh0rty said:I think there are pro's and con's to both scientific and editorial reviews.
Scientific tire tests are made in a laboratory setting, with certain fixed environment variables (controls), so that all of the compared tires are compared in the identical conditions. These controls give a honest comparison between the tires, BUT are only really valid when the environment exactly matches the controlled environment that the tests took place in. I don't know what surface they use for testing, but I would guess it is a smooth hard surface. I ride big knobby sticky Kenda Kenetics 2.35's, on the road it feels like I'm dragging a body behind me, but on dirt, they roll much faster. I don't think a 3% rolling resistance difference in scientific conditions (assuming they are testing on a hard smooth surface) will be exactly the same in all trail conditions.
Editorial reviews, while they can be biased, are usually based on real world experience of the tires, where they face the multitude of variables that make a tire good (or not good) in real world circumstances. There is the possibility tires will not be tested on equal terms (i.e. Tire A was tested after a rain storm while Tire B was tested in blistering hot dry conditions) but I think having many testers doing many tests over a long period of time would mitigate these inconsistencies.
I also disagree with the analysis that 3% difference in tire rolling resistance will directly translate into 3% faster climb or race time (off road that is). There are just too many other variables. If that where the case, every XC racer would be riding hard rubber slick's...but other factors such as rear tire traction, braking bite, cornering traction, etc. all have a BIG effect on the overall performance. i.e. On a climb you could run the lowest resistance tire in the world, but if you are losing 1/16'th of a spin of the rear wheel every pedal stroke due to poor traction, you are not going to get that 3% gain from rolling resistance, compared to an equal rider with slower rolling tires, who loses less traction on each pedal stroke.
I read the MBA tire review today at lunch, while there may have been some brand bias (I don't really see it though, there where high and low rated tires from most of the brands, the top two may be suspect?) deffiantly the biggest bias is towards dry south-west riding conditions. They never took into consideration performance in wet, muddy, slippery conditions...making the review less relevant to me, riding in the North-West, where wet riding performance is always a consideration!
You have to take any published review with a grain of salt. Read the review, apply some common sense, your own past experiences, see what has and has not worked for others riding the same trails as you, and make an informed buying decision on your next set of tires. Or, you could always use the trial and error method of finding the best tire for you...but I learned that can get pricy, and sometimes painful. ;-)
sh0rty
This point is always brought up. Common sense would tell you this.......but common sense would be wrong...
The tire with faster rolling resistance will consistantly roll faster.......both on the street and on the dirt.
I think I could make an exception to this in unusual conditions as follows.
Suppose you had a 1.25 ATB slick and were trying to ride it through some deep sandy soil......In that case perhaps the Kenetics 2.35's might allow you to float along the surface and actually be faster......but that is a rare occurance and an extreme comparison....a 1.25 slick versus a 2.35 knobby...
"I also disagree with the analysis that 3% difference in tire rolling resistance will directly translate into 3% faster climb or race time (off road that is). There are just too many other variables. If that where the case, every XC racer would be riding hard rubber slick's...but other factors such as rear tire traction, braking bite, cornering traction, etc. all have a BIG effect on the overall performance. i.e. On a climb you could run the lowest resistance tire in the world, but if you are losing 1/16'th of a spin of the rear wheel every pedal stroke due to poor traction, you are not going to get that 3% gain from rolling resistance, compared to an equal rider with slower rolling tires, who loses less traction on each pedal stroke."
Now in this case YOU are the one picking out the most unusual situation to try to make your common sense seem reasonable...
XC racers would of course never use hard rubber slicks........so lets dismiss this example.
On the other hand they might pick the best rolling resistance knobby which still gave them adequate traction....or they might even compromise a bit of traction on short sections of very steep climbs in order to gain huge advantages in all other sections..
After all the final finish line time is all that matters.....If he loses 3 seconds on one climb but gains 23 seconds on the next section, then he is still 20 seconds better off.
You put on a fresh set of Nokians and you are not going to be having your tires spinning out on every stroke of the pedals... In fact you may find they grip exactly the same as your much slower tires with larger knobs.
I think you may be making the all too common mistake of thinking that a tire with very small and shallow tread is the tire with the lowest rolling resistance.......or that lack of knobbies is the key feature affecting rolling resistance. This just isn't the case.
Low rolling resistance has a lot more to due with the tire construction than just having a smooth tread. Thats why the Nokian works so well. Grips well and rolls welll.
You want to get around a cross country course faster......to the finish line....
Get a tire with very low rolling resistance, but with just enough grip.
On the other hand if you are just out for recreational rides and time is of little consequence then take any tire that you like. Just don't make believe that over an entire course it will be faster. Faster on some particular section.....perhaps, but you will pay for it later on the course.
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155 Posts
My point was that you have to find a balance between grip and rolling resistance, and simply using the results of a rolling resistance test is not nessesaraly going to get you the best tire. IMHO real world testing and a subjective review of the overall handling properties of a tire would be more useful in selecting a tire than a scientific measurement of its rolling resistance.
sh0rty
sh0rty
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97 Posts
tire pressure can make a difference as well.I concur with the 3% gain equaling a huge difference in riding. not only will you be able to go faster but you will have more energy if you stay at the same speed to blast at the end. Ive been told that any weight you can save on the rolling parts(tires,pedals,rims,cranks etc.) multiply exponentially as it reaches the point of energy.take a pound off your frame you may get a weaker frame. take a pound off your wheels and tires you will get a lot faster.there are tires that are good and fast yet have good traction too. Panaracer trailbalster is just one example of light weight, speed, and traction in most conditions tire. I ride Cinders now and even though they are heavier than a race tire they are FAST and track very well. my avg. speed is better overall on my favorite trail due to the speed and better control
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858 Posts
Havent Read the Reviews but!
The Specialized tyres are **** BRICKS... They are heavy and roll very far from fast- Acceleration is slow, and the tyres handle well below par at low presure (stand mtb presures). I cant really think of anything good to say about them. Decent size and Cheap I guess.
Exsample: Today I switched my old well worn Enduro tyres for some new Maxxis HighRollers... The bike felt snappy, when you put the foot down it went not like with the Specilized tyres. Grip was much better also.
The may be good for training tyres, but I wouldn't pay for them unless I found them in the bargin bin.
The Specialized tyres are **** BRICKS... They are heavy and roll very far from fast- Acceleration is slow, and the tyres handle well below par at low presure (stand mtb presures). I cant really think of anything good to say about them. Decent size and Cheap I guess.
Exsample: Today I switched my old well worn Enduro tyres for some new Maxxis HighRollers... The bike felt snappy, when you put the foot down it went not like with the Specilized tyres. Grip was much better also.
The may be good for training tyres, but I wouldn't pay for them unless I found them in the bargin bin.
Scientific testing is the ONLY starting point of analysis.
That is why you need scientific measurement testing.....because rider's brains cannot imagine a different tire can really.....REALLY make that huge a difference...
Giving up a little on certain technical cornering, and perhaps slipping a bit on a climb, are gonna cost you a few seconds......but when you add up all those little bits, they normally pale in comparison to the speed you gain on the other 95% of the typical cross country course.
You need testing because "common sense" is almost always wrong in this category.
When you ride, you only notice those obvious areas where the tire may slip or may not allow you to corner quite as fast, but unnoticed by you are the other multitude of places....the 95%...where little by little....the faster tire keeps giving you tenths of seconds, thousands of times.
I'm certainly not saying that, for example, the Nokian is best for everyone on every ride.
But I am saying is that most riders.....90+ percent don't pay enough attention to rolling resistance. No problem if time is not your major concern, but if you want to win that race that is 1 or 2 or even 3 hours long, then rolling resistance is very important.
3% over 2 hours is 3.6 minutes......at even 13 mph average, thats 3/4s of a mile at the finish line....4,000 foot lead compared to the other tire minus any distance lost due to slower cornering, or tire slippage on a climb......
About the only thing that will cost you more than that 4,000 feet is if you have a realy wipeout due to lack of grip.... Even a minor crash is not going to cost you 4,000 feet.
You first need testing to establish what the gains are, and then you can do some calculations to estimate how much of those gains you may lose. For that you can be a little more subjective.
The trouble with "real world" testing is that it is too subjective. The problem with most riders is that their brains simply cannot believe that a given tire that does not look so unusual....such as the Nokian NBX 2.0 Lite.....is actually SO much faster then the tires they think are fast....sh0rty said:My point was that you have to find a balance between grip and rolling resistance, and simply using the results of a rolling resistance test is not nessesaraly going to get you the best tire. IMHO real world testing and a subjective review of the overall handling properties of a tire would be more useful in selecting a tire than a scientific measurement of its rolling resistance.
sh0rty
That is why you need scientific measurement testing.....because rider's brains cannot imagine a different tire can really.....REALLY make that huge a difference...
Giving up a little on certain technical cornering, and perhaps slipping a bit on a climb, are gonna cost you a few seconds......but when you add up all those little bits, they normally pale in comparison to the speed you gain on the other 95% of the typical cross country course.
You need testing because "common sense" is almost always wrong in this category.
When you ride, you only notice those obvious areas where the tire may slip or may not allow you to corner quite as fast, but unnoticed by you are the other multitude of places....the 95%...where little by little....the faster tire keeps giving you tenths of seconds, thousands of times.
I'm certainly not saying that, for example, the Nokian is best for everyone on every ride.
But I am saying is that most riders.....90+ percent don't pay enough attention to rolling resistance. No problem if time is not your major concern, but if you want to win that race that is 1 or 2 or even 3 hours long, then rolling resistance is very important.
3% over 2 hours is 3.6 minutes......at even 13 mph average, thats 3/4s of a mile at the finish line....4,000 foot lead compared to the other tire minus any distance lost due to slower cornering, or tire slippage on a climb......
About the only thing that will cost you more than that 4,000 feet is if you have a realy wipeout due to lack of grip.... Even a minor crash is not going to cost you 4,000 feet.
You first need testing to establish what the gains are, and then you can do some calculations to estimate how much of those gains you may lose. For that you can be a little more subjective.
rolling resistance
The german rolling resistance tests mean almost nothing. The tires are tested rolling against a hard, perfectly smooth drum. I do not ride or race on such a surface, ever. By this testing method the fastest tire would be made of solid steel, I doubt if anyone reading this would think that a tire that was as hard as solid steel would be fast on the dirt. I am all for scientific testing, but it must be done on actual dirt, including bumps, rocks, etc. The ability of a tire to absorb surface irregularities and then spring off the backside of them is a huge component of what makes it fast. This is why lower air pressures are often faster than higher. The german tests have nothing to do with riding off road, or even on the road for that matter.
I have no personal experience with the rollx, but I do have experience with mba's other highly rated tires: kenda karmas, blue groove lites, and nevegal lites. All of these are very fast tires with good grip in the right conditions. The bg is the fastest for hardpack and rocks, the karma is great in all conditons, and the nevegal rocks in the loose over hard conditions. These tires all gain significant speed when used tubeless with stans.
The german rolling resistance tests mean almost nothing. The tires are tested rolling against a hard, perfectly smooth drum. I do not ride or race on such a surface, ever. By this testing method the fastest tire would be made of solid steel, I doubt if anyone reading this would think that a tire that was as hard as solid steel would be fast on the dirt. I am all for scientific testing, but it must be done on actual dirt, including bumps, rocks, etc. The ability of a tire to absorb surface irregularities and then spring off the backside of them is a huge component of what makes it fast. This is why lower air pressures are often faster than higher. The german tests have nothing to do with riding off road, or even on the road for that matter.
I have no personal experience with the rollx, but I do have experience with mba's other highly rated tires: kenda karmas, blue groove lites, and nevegal lites. All of these are very fast tires with good grip in the right conditions. The bg is the fastest for hardpack and rocks, the karma is great in all conditons, and the nevegal rocks in the loose over hard conditions. These tires all gain significant speed when used tubeless with stans.
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Scientific or not, I can tell that my Roll-X's are slower than my Karma DTC's. Its obvious on flat pavement.barrows said:
As far as Specialized advertising in MBA, while there may be some bias (I don't know), I don't believe that advertising is really that much of a factor here. As Mcgarry said, all the other tire manufacturers advertise in MBA as well. MBA Associate editor Ed Arnet races locally in Fontana, and if you look on his bike he's running Roll-X's, and winning. One may disagree with his choice, but at least he is honest about what tires he likes.
Also, I saw one of those German magazines one time, and guess who had a full page ad, none other than Schwalbe, whose tires consistently finish at or near the top of the german rolling resistance charts. Someone posted over on "save some weight" that Schwalbe even provides the machine for the testing. Yet no one seems to accuse them of pandering to their advertisers.
In addition, Mountain Bike UK recently placed the Nokian NBX lite mid pack on their tire test as well. They said it didn't hold a line well and was too small for larger riders. This seems to go against the majority of opinions on this forum, as the tire seems to be very well liked.
The fact is that all reviews are the opinion of those particular testers, and you have to take them for what they are worth. I've found most of MBA's reviews to be pretty good, some I have disagreed with.
That being said.....Roll-X's are indeed slow...
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I guess I'm one of the few that like the RollX as a front tire. I think they're great and I've used many different tires. My favorite is the Pro Traction which seems to stick the best of the ones that I've tried (Pro, S Works, and Pro Traction).bbneu said:
They stick to terrian well, and have a very controled washout when they do go. I;ve not noted any rolling resistance problems.
I do not like them as a rear tire; I prefer a more square edged rear tire. I didn't get the out of the saddle traction that I get with other tires.
The German testing is the valid for ranking tires RR
You can knock the German roller testing, but that is the way all tires are tested whether for cars or bikes. Scientists are not complete morons. They know about rocks and other surface imperfections. Do you have any source for your opinion that a smooth surface will not give the same "relative" rankings that a rough surface would give.
The important thing is the relative rankings.....When the surface gets rougher all tires will suffer in about the same ratios as they got in the smooth testing. I'm not talking about grip but just rolling resistance.
You seem to be basing your opinion on a hunch rather than anything that can be meassured.
Do you have any proof that the relative relationships in watts rating won't remain essentially the same when tires are switched from a smooth surface to a rougher one?
You use of so called "Steel" tires is just absurd. Its the drum that is steel, not the tires.
Even the fastest tire, at the hardest pressure is nothing like steel. And in mountain tires we're talking about testing them at about 35 and 50 psi......hardly steel hard.
BTW, my bike came with the Roll-X pros and they are indeed dogs just at the German testing suggests.
One curious statement you made "The ability of a tire to absorb surface irregularities and then spring off the backside of them is a huge component of what makes it fast."
Could you please explain what you mean when you say the tire "springs" off the backside of them?
The problem with your "common sense" thinking about this issue is that you have nothing to back it up with except a very subjective opinion on what rolls faster.barrows said:
You can knock the German roller testing, but that is the way all tires are tested whether for cars or bikes. Scientists are not complete morons. They know about rocks and other surface imperfections. Do you have any source for your opinion that a smooth surface will not give the same "relative" rankings that a rough surface would give.
The important thing is the relative rankings.....When the surface gets rougher all tires will suffer in about the same ratios as they got in the smooth testing. I'm not talking about grip but just rolling resistance.
You seem to be basing your opinion on a hunch rather than anything that can be meassured.
Do you have any proof that the relative relationships in watts rating won't remain essentially the same when tires are switched from a smooth surface to a rougher one?
You use of so called "Steel" tires is just absurd. Its the drum that is steel, not the tires.
Even the fastest tire, at the hardest pressure is nothing like steel. And in mountain tires we're talking about testing them at about 35 and 50 psi......hardly steel hard.
BTW, my bike came with the Roll-X pros and they are indeed dogs just at the German testing suggests.
One curious statement you made "The ability of a tire to absorb surface irregularities and then spring off the backside of them is a huge component of what makes it fast."
Could you please explain what you mean when you say the tire "springs" off the backside of them?
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Maybe it is just me, but isn't it unfair to compare these tires. The Python has a much lower profile tread pattern than the Roll-X hence giving it an advantage in terms of decreased rolling resistance. Where as the Roll-X with it's medium profile knobs will provide a lot more traction in loose conditions than what the Python ever would. The Python excells in only one condition (hard pack), where the Roll-X, while not dominant in any condition, is an above average all conditions tire.
True and untrue.......
Actually the Roll-X is NOT above average in rolling resistance, but rather one of the worst performers.... 43.5 watt of power sucked up versus 26.2 watts for the Python Air Light
Now, in certain type of terrain the Roll-X will out perform the Python such as on a place that needs more grip.....
The real question is what are you looking for. If your main need is to cross the finish line in a 20 mile cross country race, ahead of the other guy, then I doubt you'll find many races where the Roll-X Pro would bring you out ahead of the Python Air Light.
You simply can't make up for all the extra power being sucked up by the Roll-X's by going down a few technical parts faster. The advantgage you gain on those parts is more than eaten up by the sluggish rolling on the other 90% of the course.
But if you don't care about time, and prefer the extra grip of the Roll-X, then by all means use it. Very few people are concerned about time/speed during most of their riding.
"The Python excells in only one condition (hard pack), where the Roll-X, while not dominant in any condition, is an above average all conditions tire"labraja said:
Actually the Roll-X is NOT above average in rolling resistance, but rather one of the worst performers.... 43.5 watt of power sucked up versus 26.2 watts for the Python Air Light
Now, in certain type of terrain the Roll-X will out perform the Python such as on a place that needs more grip.....
The real question is what are you looking for. If your main need is to cross the finish line in a 20 mile cross country race, ahead of the other guy, then I doubt you'll find many races where the Roll-X Pro would bring you out ahead of the Python Air Light.
You simply can't make up for all the extra power being sucked up by the Roll-X's by going down a few technical parts faster. The advantgage you gain on those parts is more than eaten up by the sluggish rolling on the other 90% of the course.
But if you don't care about time, and prefer the extra grip of the Roll-X, then by all means use it. Very few people are concerned about time/speed during most of their riding.
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