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  1. #1
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    How about a tire RR thread?

    I've been noticing more and more lately that there simply isn't enough info about RR with tires. Yes, there are some of those German testing article's available, but I don't feel they're really up to date. There's been a lot of new tire's that have come out since then and they're not tested in any way. Please understand I mean absolutely no offense or disrespect to any of those testers or the people that use that info. I myself look at these same page's and love what I see, but let's face it - it's old!

    So, what's my proposition?

    Simple. WE test tire's. There's a lot of us here in MTBR that this is important to. While I do have my own priorities in what I want in a tire, that doens't mean I can't help someone else out with some info that I may have/know. We could honestly sit here and post for hours, days or even weeks and months about it, or we can get organized and make it easy (somewhat). Between a bunch of us we probably have 80% or better of the tire's available from the past several years (also meaning CURRENT), so it's not like i'm saying we all gotta go out and buy new tire's for this. That's not the point.

    What is the point?

    Again, simple. Test the tire's we each DO have under circumstance's that we can duplicate over and over again. I myself have several place's where I test my tire's for RR. One is the paved street I live on, which has a long, gradually sloping downhill (or uphill, depending on how you look at it) and the other is a long, winding trail at my favourite riding spot. The idea would be to put on a set of tires and compare times. Sounds easy? Well .....

    Complication's.

    Ah, there's always a catch, right? Well, yeah, kinda. You gotta get off your a$$, figure it out and do it. (i'm trying to be motivational here)

    Obviously what i'm posting is a VERY generalized overview of what i'm thinking. There ARE complication's, some with easy (?) resolve, some not so easy. I have a whole bunch of tire's here I can test, but Jimmy down the street only has two. Does that mean his testing won't be as important? I don't think so, if there's some sort of guideline.

    My thought with THIS post/thread is nothing more than discussing the possibility of all of us getting together, looking at what we see as possible problems, working out resolutions and establishing some sort of "guideline's" for us to test. Yes, i'm already anticipating worn tires, bike and rider weight, psi, rims and a whole bunch of other things to screw this up and make it impossible, but surely we can figure something out.

    So, there's my idea. Who's in? Discuss, please.
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  2. #2
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    I think this is a good idea. It would be interesting if nothing else.

    I think the biggest challenge will be dealing with PSI. Specifically, comparing a small volume tire like a Kenda Klimax to a large volume tire like a Kenda Cortez.

    Possibly a way to even out the psi would be to use a given amount of strokes from a pump for every tire. I'm not sure how consistant the volume of air is in each stroke of a pump but if it is consistant, it seems that this would put a proportionately higher pressure into a smaller volume tire, that would need the higher pressure compared to a higher volume tire. Just an idea.

  3. #3
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    Quote Originally Posted by grawbass
    I think this is a good idea. It would be interesting if nothing else.

    I think the biggest challenge will be dealing with PSI. Specifically, comparing a small volume tire like a Kenda Klimax to a large volume tire like a Kenda Cortez.

    Possibly a way to even out the psi would be to use a given amount of strokes from a pump for every tire. I'm not sure how consistant the volume of air is in each stroke of a pump but if it is consistant, it seems that this would put a proportionately higher pressure into a smaller volume tire, that would need the higher pressure compared to a higher volume tire. Just an idea.
    Good point! Tire volume is something we can't change, but pressure is. Perhaps we could do the test with 3 different pressures, say 30/40/50, or 35/45/55? It's been proven/debated/questioned many times before and this would certainly be a great way to compare actual real world testing.

    Anyways, i'm off to bed. When I get home from work tomorrow i'm HOPING to see lot's of posting here with questions, concerns and maybe even solutions. Let's DO something!


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  4. #4
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    im very interested in this.
    where should we start!?

  5. #5
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    It's a good idea,but

    You have two very serious problems: accuracy and reproducability. Every single tire has to be tested under exactly the same conditions for the results to be meaningful. So you'd better hope the wind is always the same speed and the same direction every day you go out. And you take every turn on that road downhill the same way every time.....

    In short: it's unscientific and practically impossible. People here who go out and say "my new tires made me 3 min. faster on the local lap" have absolutely NO way of proving wether this is from rolling resistance or just the sheer joy of having new tires!

    I don't want to be a complete pain - your idea is a great one - but if you're going to do this, figure out a testing method that is a bit more foolproof. One thing that comes to my mind is making a tire treadmill. If you can build a wheel onto an electric motor, you can measure the power used to turn the wheel (by measuring current and voltage across the motor). Provided you can make some sort of preloaded roller for the tire to roll on (kinda like a stationary roller for a bike), and you can preload the tire the same way every time, you have a rough indication of how rolling resistances differ with tires. I say rough, because you'll need a rev counter and a multimeter. Common shop stuff or material scavanged from the junkjard isn't very accurate.

    However: if you can find the time and money to build such a contraption, results from other testers are useless unless their machine is built exactly the same in terms of motor, stiffness, etc.

  6. #6
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    I have a Powertap wheel in the planning. All I need to do I get (or pcik from stock) a rim, and get it laced up. This might be of some help to find a required power to reach a given (avg) speed over a given course.

    In testing tires, indeed wind in as issue. Ideally, you find a test track that is in the darkest part of the woods. A test IMO should be conducted as a record attempt, make the sukker rol as fast as you can, but always in the same riding position and clothing. Re-test tires, preferably ones you don't like thus don't wear out. The re-test can set a correction figure for the day, perhaps?
    Say you have a pair of tires that handle like crap and wouldn't sell them to your worst enimy to crash with. Those tires are great for each test day's benchmark. would that work? Say the Crap tire sets a time, and others are rated relative to that.

    I would also be interested to rate a tire's grip levels. Maybe by riding a given super-winding bit of singletrack where grip is everything. Also, rating conditions by riding a benchmark tire first. If the course is so technical that your today's shape is of little influence on the time, it may actually show real differences.

    I like the multiple psi testing. Especially if an ideal psi could be found for the trail at hand.

    Once someone has established a good testing course and method, people should come over and provide their tires to conduct even more testing under those same conditions. A given test site can then come up with a longer list of tires, in order of speed.

  7. #7
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    very iteresting

    love the idea first off.

    reality is, it will not be enitrely scientific, but who cares. sounds like fun.

    obviously the first thing you (we) need to do is outline the criteria for testing.

    Do you set a minimum number of tires sets to be tested? (at least 3 sets, so you can compare), because the overall end results of one individuals results will mean nothing compared to others results due to ALL the variable.
    obviously all tires must be tested the same day, as close together as possible.
    3 different pressures sounds like a good idea.
    rules about a section of trail with NO pedalling or braking, just rolling.
    run each set 3 times to get an average time or total (longer) time to compare.
    tested provide a desciption of weather and trail conditions.
    I think you almost need to create a form with the testing criteria outlined for the tester to follow (download as a PDF)?

    then, how do you organize or submit the results?
    sounds like we need some programmers to take it on and put on a web site? any takers? because, just saying I tested three sets of tires and the results were #1. twisters #2. nbx #3. racing ralphs, although interesting, does not really provide enough info for any of us to evaluate if this info helps us. we need to know conditions, length of test site etc.

    finally, how do we compare any information from different users? i don't think we can, i think each set of results will have to stand on it's own and it is up to the rest of use to look over the results and decide what is useful to our riding style and conditions.

    ok, let me know when you want my results? i love coasting....

  8. #8
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    That's the way to go. Publish results numbered, not with wattage or anything. Relative differences can be interesting though, maybe with "#1. twisters #2. nbx #3. racing ralphs" there was a huge diff between 1 and 2, or 2 or 3.
    With more and more results coming in, completer lists can be created of which tires roll fast, relative to each other, in various conditions. The racing ralph in above example might roll faster over tacky soil even than the twister, but lose out over deep dust/sand.

  9. #9
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    Quote Originally Posted by Cloxxki
    That's the way to go. Publish results numbered, not with wattage or anything. Relative differences can be interesting though, maybe with "#1. twisters #2. nbx #3. racing ralphs" there was a huge diff between 1 and 2, or 2 or 3.
    With more and more results coming in, completer lists can be created of which tires roll fast, relative to each other, in various conditions. The racing ralph in above example might roll faster over tacky soil even than the twister, but lose out over deep dust/sand.

    I was going to make a joke in the other rolling resistance thread that the Weight Weenies website be changed to Rolling Resistance Weenie. But this really seems the way to go. Weight Weenies website uses user imput and a vast assemblage of scales accurate or not or with variance. The averaging helps to bring the numbers together. And inspite of these potential inaccuracies, it remains one of our greatest sources of information.

    It clearly trumps the companies marketing information.

    Mr. P

  10. #10
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    Excellent! Okay, so you (we) all know that this WON'T be 100%. The next question, I feel, is what kind of compromise(s) are we willing to accept?

    I already pointed out a couple of things which have been expanded by others. Things like wind resistance, tire volume, tire/tube pressure, terrain and other's will undoubtedly be a PROBLEM. Understand, I truly realize this and with these kinds of complications something like this CAN'T be 100%. Again, compromise.

    Personally, I was thinking along the line's of what Cloxxki suggested, below, follwed with Kev's comments;

    Quote Originally Posted by Cloxxki
    That's the way to go. Publish results numbered, not with wattage or anything. Relative differences can be interesting though, maybe with "#1. twisters #2. nbx #3. racing ralphs" there was a huge diff between 1 and 2, or 2 or 3.
    With more and more results coming in, completer lists can be created of which tires roll fast, relative to each other, in various conditions. The racing ralph in above example might roll faster over tacky soil even than the twister, but lose out over deep dust/sand.
    Quote Originally Posted by Kevbikemad
    (at least 3 sets, so you can compare), because the overall end results of one individuals results will mean nothing compared to others results due to ALL the variable.
    obviously all tires must be tested the same day, as close together as possible.
    3 different pressures sounds like a good idea.
    rules about a section of trail with NO pedalling or braking, just rolling.
    run each set 3 times to get an average time or total (longer) time to compare.
    tested provide a desciption of weather and trail conditions.
    Again, at this point it's just a suggestion but I feel these are "the best bet". People who have more tire's like myself could spend HOURS testing matching and mixed pairs, posting what time's resulted with various combinations. IMHO, little compromise is to be needed here. You have the same rider and bike, with only the tire's (and possibly tubes, if you're running UST/tubeless .... then I feel REALLY sorry for you) changing.

    Lap timing - I don't see how this could work really. We all know who we're talking about here. While I feel Nino has great input and I feel that his number's ARE valid it's very hard to take into consideration so many possible factors. Does this mean I don't believe him? Absolutely NOT! If anyone here is reading this thread with ANY interest then this tells me that you know the difference between a fast- and slow-rolling tire and that you CAN appreciate a difference in lap times (it only make's sense as being a racer it's your goal). So, with this in mind IS there a way that these lap numbers CAN be MADE valid? Personally, I don't know how. Suggestions on this matter are more than appreciated.

    Now, with this whole lap time thing it take's us to another thing that's been discussed - energy. As soon as the bike is being moved by pedal input then right there you're adding numerous factor's into the equation. Is this something that is really going to help us, or just hinder an already complicated matter? I feel that it's best to make all/any testing with no power at all, simply coasting. I know, if you've really thought about this by now then you're going to say "Yeah, but I have King hubs and they're making me slower because of freehub drag" or "yeah, but my bearing preload is tighter than his". Really, if we're going to nit-pick this too much then I honestly say it all stops right here.

    Again, compromises must be understood - I never claimed this would be a perfect test and made that clear from my first post. If you want that then YOU go out and buy 50 or 100 tires and find the time to test them. I can live with variance's here and there. I don't put on brand new tire's every time I ride, do you?.. Pardon me if i'm sounding a bit harsh with this, but again - COMPROMISE! (read kevbikemad's post opening - he gets it). Do you all want to mail your tires to one guy to test them? I sure don't! As much as i'd love to spend the time and money doing such a test i've got better things to do (like RIDE!!!!) and other things to spend my money on. Wanna make donations? Hmmm, I didn't think so. If we can pull together and understand the compromise's and test what each of us do have then we stand a chance.

    Last up is the final important factor - unit measurement. Personally, I don't care if you do your testing in kph or mph, both can be listed easily. The importance is HOW this number is achieved. My suggestion; for flat OR slight downgrades you choose THREE points. Point #1 is an actual physical starting point. This is where you physically take your feet of the ground and get your speed up to a certain point, then you reach point #2. Point two is where you monitor your speed (where it should start dropping, if you were pedalling to get to point #2 then you stop pedalling at point #2). This is where the testing area begin's. Between point #1 and point #2 you are using this as a "normalizing/stabilizing/balancing" zone. You proceed, coasting only, to point #3 where you check your speed again. The final speed and starting speed are then taken, subtracted and this final value is a datum. (just a rough idea here, but you get my point, i'm sure someone else has a better way?????)

    More input. So far I like the positive input I see. I respect the other input also. I'd like to reserve any further "issues" like information representation/processing untill after we get a decent core of people into this that will help out and resolve current issue's. Untill then I fear it will only complicate an already complicated issue. Perhaps by that point some of us may have come up with something while stewing about this at work.

    Oh, one LAST thing - if two or more tester's have the SAME tire then ALL the input is collected and shown on an individual basis, NOT averaged. Variable's taken into consideration are bike setup, rider weight, etc. It's ALL important. (read: four tester's average their three tests, all four tester's get their own "slot" to input info)


    Eric - you're not a pain, complete or otherwise. I've made my comments above trying to be respectful and appreciative. Hopefully I portrayed that properly and you might see where i'm coming from with all of this. Honestly, I don't see a "perfect" tire test possible unless you're rich. So, that said, how many tire's do you have to contribute with testing? If not for yourself, then think of other's that might stand to gain something. I myself am not a racer and would love to hear of your collection (?) and what you can do to help us out.
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  11. #11
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    :)

    ...
    Last edited by lftripp33; 01-24-2006 at 08:55 PM. Reason: Done with this...
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  12. #12
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    Quote Originally Posted by lftripp33
    Make a compound pendulum. Connect two identical wheels together with an axle. Then put a weight that is not center on the axle. Then put the tires that you wish to test on the wheels and inflate the tires to the same pressure. Equilibrium will happen when the weight is closest to the ground. This will be the zero position. Rotate the wheel 90d and let the wheels go. At the same time start a timer. Time the oscillations and time how long it takes to stop at zero position. The rate of decay will be directly related to the rolling resistance of the tire. The tire with largest amount of time will be the tire with the best rolling resistance. Done, now that was easy. I cant take the credit for this one though. My college adviser Dr. Wang developed it.
    I looked it up on Google. I'm not even going to pretend I understand how this will work. Interesting at the very least! Can you privide a pic or something? I'm just not understanding it.
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  13. #13
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    :)

    ***
    Last edited by lftripp33; 01-24-2006 at 08:58 PM. Reason: Done with this...
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  14. #14
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    Come on guys, you should leave it to Hans and Franz

    Are you kidding yourself.
    Anyone and everyone should know that only Germans are technically competent enough to test Rolling Resistance.
    Its something in their genetic makeup that allows them to do it.
    Others are simply not capable. History has proven that.
    That is why they don't even bother to translate the results into English, and certainly not into French or Italian. Lucky for us that Nino is multi-lingual being Swiss.

    They test it.......we read it......and we accept their results.
    Thats the way its always been and thats the way it always will be.
    "So it was written in scripture, so be it forever"

    Germans are good at testing tires..........other nationalities are good at video games.
    Lets leave it to Hans and Franz to "pump the tires up"

    I just wish Hans and Franz would test more tires more often and under more varied tests.

  15. #15
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    Quote Originally Posted by lftripp33
    The first picture is the rig. The other picture is what the graph will look like. The only tricky part is collecting the time data accurately, but with the right equipment that's not too hard. In one of my classes we were testing Lego wheel rolling resistance. We used those fancy Lego computer brick things with a light sensor attached to time the oscillations. Then put the data into excel and got a graph that looks like the one pictured.
    I only see ONE problem with your proposal (although it IS a neat idea!!!) - you can't steer it. If you don't have a long enough stretch of trail to test in a straight line then how do you overcome this?

    Example; the one area of trail that I can tell within minute of riding on my favourite trail has a looooong slow left-hand turn. See what I mean?
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  16. #16
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    Quote Originally Posted by Chester
    Are you kidding yourself.
    Anyone and everyone should know that only Germans are technically competent enough to test Rolling Resistance.
    Its something in their genetic makeup that allows them to do it.
    Others are simply not capable. History has proven that.
    That is why they don't even bother to translate the results into English, and certainly not into French or Italian. Lucky for us that Nino is multi-lingual being Swiss.

    They test it.......we read it......and we accept their results.
    Thats the way its always been and thats the way it always will be.
    "So it was written in scripture, so be it forever"

    Germans are good at testing tires..........other nationalities are good at video games.
    Lets leave it to Hans and Franz to "pump the tires up"

    I just wish Hans and Franz would test more tires more often and under more varied tests.
    No, i'm not kidding. I don't see why we can't get our heads together to get something going here. Like i've said before - compromise, understanding, blah blah blah.

    I don't see "Hans and Franz" testing anything NEW. Where's the Schwalbe Nic's? Where's all the other tire's that have come out in the past TWO-PLUS YEARS?

    So, who are YOU kidding?

    Shame on you for even thinking genetics come into this, Chester. Perhaps you can add something usefull? I have an idea, let's start with - how many tires do you have? What type's of terrain can you offer with your testing?
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  17. #17
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    Quote Originally Posted by AndrewTO
    No, i'm not kidding. I don't see why we can't get our heads together to get something going here. Like i've said before - compromise, understanding, blah blah blah.

    I don't see "Hans and Franz" testing anything NEW. Where's the Schwalbe Nic's? Where's all the other tire's that have come out in the past TWO-PLUS YEARS?

    So, who are YOU kidding?

    Shame on you for even thinking genetics come into this, Chester. Perhaps you can add something usefull? I have an idea, let's start with - how many tires do you have? What type's of terrain can you offer with your testing?
    I am curious as to why these rolling resistance test never have the Kenda Karmas in them. I think they are one of the best balances between weight, rolling resistance, and grip that I have used, along with have a nice high volume to them. They seem to be a pretty popular racer choice, but unless I have missed something, I have not seen them appear in one of the German tests. Nino, have you ever used them? I would be curious as to your feedback how they compare to the RRs and NBXs.
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  18. #18
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    New tire 250 grams, will report back on RR

    Just got a Specialized All Conditioned Pro 26.0 x 1.0 tire with Kevlar etc foldable....

    Says it operates from 115 to 125 psi....
    Is said to have FlackJacket protection from flats...

    Now to be fair, it may not grip too well on the loose stuff

    However I'm using it out on the road for a training tire...
    120 psi......Yikes!!

    I've been playing with a Performance 26 x 1.25 tire at about 100 psi (only rated 85) so I want to see how this compares in rolling resistance. Should be at least a bit better huh?
    The Performance tire, BTW, is now on sale for about $8.00......wow....good deal for a street tire... The 26x1.25 weighs about 350 grams.
    Just weighed the new Specialized 26x1.0 at about 250 grams even though they advertise 285 grams...

    Now to slap it on, and go out and chase some roadies

  19. #19
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    Quote Originally Posted by Fett
    I am curious as to why these rolling resistance test never have the Kenda Karmas in them. I think they are one of the best balances between weight, rolling resistance, and grip that I have used, along with have a nice high volume to them. They seem to be a pretty popular racer choice, but unless I have missed something, I have not seen them appear in one of the German tests. Nino, have you ever used them? I would be curious as to your feedback how they compare to the RRs and NBXs.
    Let's test them and compare them against another set of tires. How many tire's do you have that we can compare them to within your individual tests?

    Think about it, you have a whole bunch of people that repost their findings. With enough data we CAN filter out some kind of "order" to a reasonable extent. With some good testing, reporting and organization I dont see why we can't have a decent list that would be able to show fastest to slowest. The key is cross-referencing.
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  20. #20
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    Quote Originally Posted by Chester
    Just got a Specialized All Conditioned Pro 26.0 x 1.0 tire with Kevlar etc foldable....

    Says it operates from 115 to 125 psi....
    Is said to have FlackJacket protection from flats...

    Now to be fair, it may not grip too well on the loose stuff

    However I'm using it out on the road for a training tire...
    120 psi......Yikes!!

    I've been playing with a Performance 26 x 1.25 tire at about 100 psi (only rated 85) so I want to see how this compares in rolling resistance. Should be at least a bit better huh?
    The Performance tire, BTW, is now on sale for about $8.00......wow....good deal for a street tire... The 26x1.25 weighs about 350 grams.
    Just weighed the new Specialized 26x1.0 at about 250 grams even though they advertise 285 grams...

    Now to slap it on, and go out and chase some roadies
    HAHAHA! Well we already know that you'll have the tire's with the least RR, won't we Chester? Good show!

    I think that it would be great to get a few slicks into this. They might be closer to each other (?), but it SURE would be interesting.
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  21. #21
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    Interesting example of a RR site........mostly for street tires

    take a look at this site and how it is set up...

    Check out the 559 tires....

    http://www.legslarry.beerdrinkers.co.uk/tech/JL.htm

    My Specialized All Condition Pro tire which are the subsequent edition of the Specialzed Turbo S ATB tire, came out near the top in RR for the 559 tires

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