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  1. #5101
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    Quote Originally Posted by Kawigreen99 View Post
    For around the price of Hopes, what can you really get that is lighter and as durable?
    DT Swiss 350 are the same weight as Hopes, maybe 10g lighter, and MORE durable in my experience. Roughly the same price, depending where you're purchasing.

  2. #5102
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    Quote Originally Posted by Kawigreen99 View Post
    For around the price of Hopes, what can you really get that is lighter and as durable?
    I really have never considered Hope hubs light. Blingy yes, loud yes, durability I have heard some serious complaints. But also a lot of praise. As another poster said I would consider a lower end DT Swiss before a rear hope hub. As far as AC hubs go I have never had an issue. I have a 13 year old hub on my wife's bike that had never been serviced and still works great. I have even used an AC hub for my bike I use for the ski hill. But for where I ride regularly I have never had a need for a high POE hub as they say ymmv.
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  3. #5103
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    Quote Originally Posted by spunkmtb View Post
    I really have never considered Hope hubs light. Blingy yes, loud yes, durability I have heard some serious complaints. But also a lot of praise. As another poster said I would consider a lower end DT Swiss before a rear hope hub.
    The 350 is a great hub, no doubt, but weighs the same and is lower POE than the Hope.
    IME Hope durability issues are rare.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  4. #5104
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    after breaking a flow rim (not a Flow EX and not the rim's fault) I ordered up some LB, "new process", 29er, beadhookless, inner width 22mm, published weight 365g rims.

    I found lot's of people here with positive comments on wheel weight and stiffness with carbon so I did some measurements with the RIMS only. This doesn't translate directly to overall wheel stiffness, and I'm not sure how representative a lateral and then radial static force is of actual forces during mtn biking, but it is at least a quantitative data point that I didn't easily find elsewhere (searched, but didn't read entire thread here...).

    I weighed the rims using a gram scale and I measured the deflection by hanging an approximate 16 lb weight (see images)

    I'll list the data in the following order: rim type, measured weight, radial deflection, lateral deflection,

    DATA:
    FLOW, 535g, .070inch, .348inch
    LB, 363g, .048inch, .421inch

    In conclusion, my LB rims are 32% lighter, 21% less lateraly stiff, 31% more radially stiff. And I can't wait to lace them up!

    (Cheap) Chinese Carbon Rims?-flow-lateral-.348.jpgName:  flow radial2 .070.JPG
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  5. #5105
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    Re: (Cheap) Chinese Carbon Rims?

    I hate to be the bearer of bad news, but the measurement needs to be done with the rims laced up. Doing it this way means almost nothing.
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  6. #5106
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    Quote Originally Posted by yourdaguy View Post
    I hate to be the bearer of bad news, but the measurement needs to be done with the rims laced up. Doing it this way means almost nothing.
    You're not the bearer of bad news... you are the bearer or incorrect information.
    How the rim itself responds to loads relative to other rims tested in the same way absolutely has meaning.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  7. #5107
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    But not nearly as much as the testing of the system as a whole.
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  8. #5108
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    Quote Originally Posted by yourdaguy View Post
    I hate to be the bearer of bad news, but the measurement needs to be done with the rims laced up. Doing it this way means almost nothing.
    Stronger/stiffer wheel starts with stronger/stiffer rim. For example, a Flow builds up stronger/stiffer then a Crest.

  9. #5109
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    I expected the LB rims to be stiffer radially (which it was), but also expected it to be even stiffer laterally. I'm surprised that it shows more lateral deflection than a Flow rim. It sure doesn't feel that way when being ridden or when building/tensioning the rim. Anybody else surprised by that?!?

  10. #5110
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    Quote Originally Posted by albertdc View Post
    I expected the LB rims to be stiffer radially (which it was), but also expected it to be even stiffer laterally. I'm surprised that it shows more lateral deflection than a Flow rim. It sure doesn't feel that way when being ridden or when building/tensioning the rim. Anybody else surprised by that?!?
    I'm slightly surprised, but at the same time I'd be curious how it fares compared to an arch or crest since they're closer in weight to the light bicycle rim. I went from crests to the LB rims and noticed a significant increase in stiffness and much less frequent need for truing.

  11. #5111
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    Quote Originally Posted by tiflow_21 View Post
    I'm slightly surprised, but at the same time I'd be curious how it fares compared to an arch or crest since they're closer in weight to the light bicycle rim. I went from crests to the LB rims and noticed a significant increase in stiffness and much less frequent need for truing.
    I was thinking of the Arch rim when I posted my response. Not until I read your post did it sink in that he was comparing to the big beefy Flow rim.
    Agreed, that it would be cool to see that test with an Arch rim. I felt a noticeable improvement in handling going from Arch rims to LB rims - would be nice to see the data to support the "feels stiffer" description.

  12. #5112
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    Quote Originally Posted by albertdc View Post
    I was thinking of the Arch rim when I posted my response. Not until I read your post did it sink in that he was comparing to the big beefy Flow rim.
    Agreed, that it would be cool to see that test with an Arch rim. I felt a noticeable improvement in handling going from Arch rims to LB rims - would be nice to see the data to support the "feels stiffer" description.
    The LB wider "hookbead" rims are about 70g lighter than Stan's Arch. I have two wheelsets using both rims and the LB rims feel noticeably stiffer. Not scientific but there you go! ;-)

  13. #5113
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    Interesting comparison. There's a video on Stan's website comparing the Stans Valour (not yet out) wheels to some from enve claiming that too much radial stiffness is a bad thing with respect to ride quality. They claim a weight estimate of 1230g for the 29er wheels whenever they come out! Pretty impressive numbers...

    Do all yo'all think lateral stiffness is the be all and end all with carbon hoops or is stans idea of a vertically compliant wheel a factor. I could see it on a hard tail but I have 140 mm of travel so I'll take stiff.


  14. #5114
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    Quote Originally Posted by Oaktree View Post
    after breaking a flow rim (not a Flow EX and not the rim's fault) I ordered up some LB, "new process", 29er, beadhookless, inner width 22mm, published weight 365g rims.

    I found lot's of people here with positive comments on wheel weight and stiffness with carbon so I did some measurements with the RIMS only. This doesn't translate directly to overall wheel stiffness, and I'm not sure how representative a lateral and then radial static force is of actual forces during mtn biking, but it is at least a quantitative data point that I didn't easily find elsewhere (searched, but didn't read entire thread here...).

    I weighed the rims using a gram scale and I measured the deflection by hanging an approximate 16 lb weight (see images)

    I'll list the data in the following order: rim type, measured weight, radial deflection, lateral deflection,

    DATA:
    FLOW, 535g, .070inch, .348inch
    LB, 363g, .048inch, .421inch

    In conclusion, my LB rims are 32% lighter, 21% less lateraly stiff, 31% more radially stiff. And I can't wait to lace them up!

    Click image for larger version. 

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    Cool test and simple enough for a lot of people to do....maybe we can come up with some standards to test other rims.....

    I do agree that this test is better than a built up wheel because it will isolate the results to the rim only, not introducing other variables.....type of spoke, tension of spoke, height of hub flange, etc.....

    Couple other observations:

    1. You should conduct the test on a steel top table bolted to the ground to prevent any movement or compression of the wood top.

    2. when you are doing the lateral test, you need to hold it down at the 1/2 way point and also hold it down right at the edge of the table. The rim can actually create a bow if you hold down the back and give bad results..

  15. #5115
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    Interesting! I hereby nominate you to similarly test all rims on the market.

    How do you feel about the meaningfulness of the lateral test. When built up as a complete wheel, it seems that lateral stiffness is tied to radial stiffness. The deformation during the lateral test would likely be different. Any engineers out there that can comment on how or if the forces are transferred differently when laced to a hub?

    It could be placebo, but when I first got my wider light-bicycle 29er rims, they seemed way stiffer than all the aluminum rims I've ever ridden. The placebo effect is powerful so that is possible. My guess though is that the carbon rims really are stiffer.

  16. #5116
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    Quote Originally Posted by JeroenK View Post
    YaMon, have you ever ridden hookless rims yourself? Any first hand experience of hookless rims burping?

    If so, please enlighten us with backup of your claims from of your own experience.

    If not, please leave...
    And why are you qualified to be answering this question? Here is a response from an engineer with Maxxis tires:

    Yes. Another thing to consider is that the aramid bead of a typical folding tire or tubeless / tubeless ready tire is elastic. A larger volume tire will see a higher hoop stress, and subsequently more bead stretch, at the same inflation pressure compared to a smaller volume tire. More bead stretch can lead to rim failure as the bead moves up and away from the bead seat shelf. This puts more leverage on the rim, and can lead to rim failure. (Pretty cool to see in slow motion.)

    Let's put this nonsense to sleep....
    Last edited by Atomik Carbon; 01-29-2014 at 06:26 AM. Reason: grammar

  17. #5117
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    Quote Originally Posted by dfiler View Post
    Interesting! I hereby nominate you to similarly test all rims on the market.

    How do you feel about the meaningfulness of the lateral test. When built up as a complete wheel, it seems that lateral stiffness is tied to radial stiffness. The deformation during the lateral test would likely be different.
    Yes, you are correct...it would be different, but the difference would be the same if you laced all the rims identically.....same hubs, spokes, tension, etc....that will not be possible because there are so many combinations. This test would isolate the strength of the rim ONLY.....a very meaningful test when compared to other rims tested the same identical way. We don't have to have one person test all the rims as long as we hold to the same rule set, the dial gauge is cheap ( I already have one coming )....

  18. #5118
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    Quote Originally Posted by SJDude View Post
    Interesting comparison. There's a video on Stan's website comparing the Stans Valour (not yet out) wheels to some from enve claiming that too much radial stiffness is a bad thing with respect to ride quality. They claim a weight estimate of 1230g for the 29er wheels whenever they come out! Pretty impressive numbers...

    Do all yo'all think lateral stiffness is the be all and end all with carbon hoops or is stans idea of a vertically compliant wheel a factor. I could see it on a hard tail but I have 140 mm of travel so I'll take stiff.

    Well I certainly don't know how everyone feels about this, but riding a stiff wheel transforms the handling of the bike in a POSITIVE way. I had a friend of mine that weights 250+ pounds try out a set of carbon rims and he came back saying that he did not realize that he was adapting his riding to compensate for the Stans Flow Ex flexing. He realized he was actually over/under correcting when turning into corners.....not with the carbon hoops, they go where you point. One thing I can say is that tire pressure becomes a lot more critical with carbon hoops.....

  19. #5119
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    Thanks for the feedback!

    If we ignore braking and accelerating then the load imparted by the ground is always either radial (vertical) or radial and lateral (combined forces when cornering). My gut feeling is that the vertical component is typically larger during cross country and trail riding. So, the vertical stiffness would dominate the "stiffness feel" of the wheel. In other words, I won't be surprised if these are generally as stiff as my Flows.

    Also, regarding Stan's claim I would tend to agree with SJDude that the vertical compliance may improve ride comfort but I'll add that intentionally allowing the hoops to flex and therefore no longer be round sounds like an added power "transmission loss" (however minute) - let the tires and suspension do their job. I'd still love a pair of Stan's in carbon, I'm sure they'll be sick.

    If someone finds Industry standards and gets me rims I'll volunteer to repeat the tests and publish results.

    Yes, YaMon - I started on a steel top but moved to wood so as not to harm my new beauties! But, I did test both samples on the same table, with the same fixturing, the same (halfway) overhang and weight, so I did my best to mitigate any deviations.

  20. #5120
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    Quote Originally Posted by Oaktree View Post
    Thanks for the feedback!

    If we ignore braking and accelerating then the load imparted by the ground is always either radial (vertical) or radial and lateral (combined forces when cornering). My gut feeling is that the vertical component is typically larger during cross country and trail riding. So, the vertical stiffness would dominate the "stiffness feel" of the wheel. In other words, I won't be surprised if these are generally as stiff as my Flows.

    Also, regarding Stan's claim I would tend to agree with SJDude that the vertical compliance may improve ride comfort but I'll add that intentionally allowing the hoops to flex and therefore no longer be round sounds like an added power "transmission loss" (however minute) - let the tires and suspension do their job. I'd still love a pair of Stan's in carbon, I'm sure they'll be sick.

    If someone finds Industry standards and gets me rims I'll volunteer to repeat the tests and publish results.

    Yes, YaMon - I started on a steel top but moved to wood so as not to harm my new beauties! But, I did test both samples on the same table, with the same fixturing, the same (halfway) overhang and weight, so I did my best to mitigate any deviations.
    I will check to see if I have any leftover 1/4" lexan sheets for you to screw down to your table to protect the rims.....

  21. #5121
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    Just thinking, maybe stans have found the lateral stiffness to be less and are covering all bases and expecting someone to test them hence the language in the video about less stiff. It is what Oaktree found.
    Very interesting thread of late. How much do you weigh Oaktree? I too am intrested in a set of these LB rims and trying to decide on the ones you have or the HD version of it with a 50g weight penalty. Or even the 35mm hookless. Any thoughts after your testing?
    I'm a good 200lb ready to ride.

  22. #5122
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    Quote Originally Posted by YaMon View Post
    And why are you qualified to be answering this question? Here is a response from an engineer with Maxxis tires:
    I thought you left. Too bad. The hunger for attention came back? This is my last post feeding it.

    "Qualified" to ask you a quesion? It's not me arguing all kind of things based on theory. That's you. Obviously I can draw that conclusion, because you have not mentioned your own experience with hookless rims. Why on earth would we even care about theory if little problems exist in the real world? I really do not know why you'd like to warn people for something and frankly, I do not want to know. It's like the solution if you are against gay marriage: don't marry a gay person. Same goes here: don't buy them! That'll teach them...

    If you are that motivated to prove hookless rims do not work, you better start advocating them. More buyers = more information about possible issues, as multiple pages about Schwalbe tires blowing off Notubes rims will show. Real world stories about a bead hook not able to prevent bead stretch.

    I am going to find out myself if hookless rims work, like others have done before me. If they do not, I'll be honest about it.

  23. #5123
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    Quote Originally Posted by Andy17 View Post
    Just thinking, maybe stans have found the lateral stiffness to be less and are covering all bases and expecting someone to test them hence the language in the video about less stiff. It is what Oaktree found.
    Very interesting thread of late. How much do you weigh Oaktree? I too am intrested in a set of these LB rims and trying to decide on the ones you have or the HD version of it with a 50g weight penalty. Or even the 35mm hookless. Any thoughts after your testing?
    I'm a good 200lb ready to ride.
    Personally I would stay away from any lip less design. Here is a posting from Maxxis engineer B Holwell on that subect:

    Yes. Another thing to consider is that the aramid bead of a typical folding tire or tubeless / tubeless ready tire is elastic. A larger volume tire will see a higher hoop stress, and subsequently more bead stretch, at the same inflation pressure compared to a smaller volume tire. More bead stretch can lead to rim failure as the bead moves up and away from the bead seat shelf. This puts more leverage on the rim, and can lead to rim failure. (Pretty cool to see in slow motion.)

  24. #5124
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    Quote Originally Posted by YaMon View Post
    Yes, you are correct...it would be different, but the difference would be the same if you laced all the rims identically.....same hubs, spokes, tension, etc....that will not be possible because there are so many combinations. This test would isolate the strength of the rim ONLY.....a very meaningful test when compared to other rims tested the same identical way. We don't have to have one person test all the rims as long as we hold to the same rule set, the dial gauge is cheap ( I already have one coming )....
    Certainly lacing differences can be eliminated and rims tested alone. The question is, does it mean anything? Or more specifically, does it mean anything to us riders?

    For example, monocoque structures use their skin to strengthen an otherwise weak frame. In such a system, you could test the strength of one frame design vs another without the skin being involved. However this test might be misleading. Once the skin is added, a monocoque structure based upon a weak frame design might end up being stronger than a a one with a strong frame design.

    It could be that a laced wheel's lateral stiffness is significantly impacted by the radial stiffness. I really don't know.

    Don't let me dissuade you from conducting the test though. Thanks for performing them! At the same time, it would be interesting to know if the results are representative of a fully built wheel.

  25. #5125
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    Quote Originally Posted by JeroenK View Post
    I thought you left. Too bad. The hunger for attention came back? This is my last post feeding it.

    "Qualified" to ask you a quesion? It's not me arguing all kind of things based on theory. That's you. Obviously I can draw that conclusion, because you have not mentioned your own experience with hookless rims. Why on earth would we even care about theory if little problems exist in the real world? I really do not know why you'd like to warn people for something and frankly, I do not want to know. It's like the solution if you are against gay marriage: don't marry a gay person. Same goes here: don't buy them! That'll teach them...

    If you are that motivated to prove hookless rims do not work, you better start advocating them. More buyers = more information about possible issues, as multiple pages about Schwalbe tires blowing off Notubes rims will show. Real world stories about a bead hook not able to prevent bead stretch.

    I am going to find out myself if hookless rims work, like others have done before me. If they do not, I'll be honest about it.
    Blind leading the Blind.......It's all about the Natural Order......eventually all the stupid people will die off.......

    I can play that game too and I am good at it, start with a bad attitude and you get the same response....
    Last edited by Atomik Carbon; 01-29-2014 at 07:32 AM. Reason: add

  26. #5126
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    Quote Originally Posted by dfiler View Post
    Certainly lacing differences can be eliminated and rims tested alone. The question is, does it mean anything? Or more specifically, does it mean anything to us riders?

    For example, monocoque structures use their skin to strengthen an otherwise weak frame. In such a system, you could test the strength of one frame design vs another without the skin being involved. However this test might be misleading. Once the skin is added, a monocoque structure based upon a weak frame design might end up being stronger than a a one with a strong frame design.

    It could be that a laced wheel's lateral stiffness is significantly impacted by the radial stiffness. I really don't know. Don't let me dissuade you from conducting the test though. Thanks for performing them! At the same time, it would be interesting to know if the results are representative of a fully built wheel.
    Good argument...however we are not testing an exoskeleton where the strength is in the skin.....think of it as a truss frame where the actual components building it are being stressed. Do you think a frame made with 1x2 's will be as strong as a frame made with 2x4's??

  27. #5127
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    On rim stiffness, wouldn't any minor vertical rim flex be completely lost as noise when compared to the movement you're going to get from 2.x" knobby tires running at relatively low pressure on a relatively soft dirt surface? Add in bike suspension, and it's hard for me to understand how it would be noticeable in the real world. Then again, I'm happy on my Crest rims, so I may not be sensitive at all to wheel flex.

  28. #5128
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    Quote Originally Posted by TechniKal View Post
    On rim stiffness, wouldn't any minor vertical rim flex be completely lost as noise when compared to the movement you're going to get from 2.x" knobby tires running at relatively low pressure on a relatively soft dirt surface? Add in bike suspension, and it's hard for me to understand how it would be noticeable in the real world. Then again, I'm happy on my Crest rims, so I may not be sensitive at all to wheel flex.
    You need to go out and demo a set of carbon wheels and see what you are missing...

  29. #5129
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    Quote Originally Posted by YaMon View Post
    Good argument...however we are not testing an exoskeleton where the strength is in the skin.....think of it as a truss frame where the actual components building it are being stressed. Do you think a frame made with 1x2 's will be as strong as a frame made with 2x4's??
    It really isn't an argument so much as a question. To get a definitive answer, it would likely take an engineer who's educated in force diagrams, statics, etc.

    The 1x2 vs 2x4 wall analogy doesn't seem accurate to me. A better analogy would be that of a structure built with engineered lumber joists vs a structure built with solid wood joists.

    Engineered lumber looks like wooden I-beams and typically consist of an oriented strand board element and two natural wood elements. Individually these pieces are weak and the beams/joists are indeed weaker laterally. However, once assembled into engineered lumber joists and then assembled into a structure, that final structure is much stronger in every direction than one made of normal wood. That is an example of where a individual structural element can be weaker in one direction but the final structure actually stronger.

    Whether that is the case with hub/spoke/rim system, I don't know. But it seems possible. Testing the lateral stiffness of only a rim might be the equivalent of testing the lateral stiffness of engineered vs normal lumber. The results would be correct and reproducible, however they might not be indicative of which builds a stronger assembled structure.

  30. #5130
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    +1 dfiled
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  31. #5131
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    Quote Originally Posted by dfiler View Post
    It really isn't an argument so much as a question. To get a definitive answer, it would likely take an engineer who's educated in force diagrams, statics, etc.

    The 1x2 vs 2x4 wall analogy doesn't seem accurate to me. A better analogy would be that of a structure built with engineered lumber joists vs a structure built with solid wood joists.

    Engineered lumber looks like wooden I-beams and typically consist of an oriented strand board element and two natural wood elements. Individually these pieces are weak and the beams/joists are indeed weaker laterally. However, once assembled into engineered lumber joists and then assembled into a structure, that final structure is much stronger in every direction than one made of normal wood. That is an example of where a individual structural element can be weaker in one direction but the final structure actually stronger.

    Whether that is the case with hub/spoke/rim system, I don't know. But it seems possible. Testing the lateral stiffness of only a rim might be the equivalent of testing the lateral stiffness of engineered vs normal lumber. The results would be correct and reproducible, however they might not be indicative of which builds a stronger assembled structure.
    Good argument, but I still feel that the parts add up to the sum.......start with a weak component vs. a stronger one and the results will be different. All I am saying is build a structure using weaker components and compare it to the exactly same structure built with stronger components and see what the results are .......will that 2" x 1/4" screw build a weaker structure that if it were bolted together with a 2" x 3/8" lag bolt ??? I don't know, but it sure does seem like it would, otherwise we would use 2" drywall screws....

  32. #5132
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    Interesting as it is, looking at rim only deflection doesn't mean dick. The spokes tie a rim down by triangulation, so a rim with less lateral strength but mega high radial strength supports the lower lateral deflection characteristic by its enhanced radial characteristic. Any lateral deflection is counteracted by the spokes, and they do that through transferring the force from lateral to radial and vice versa. Pick a rim that can take a high spoke load and build with good high tensile spokes, that'll give you the best wheel.

    The rim bead hook is there to keep the tyre on, it only helps to keep the inner bead on during a cornering move. When the tyre is forced ove rby cornering loads the outside of the tyre is kept in place by air pressure (hence why burping happens at extreme lean angles/forces). If the sidewall of the rim is high enough it makes no difference if you have a hook or not, your tyre ain't coming off the inside.

    What a hook does give you though is a slight geometric increase in the effective OD of the rim, it equates to the same thing in terms of tyre retention as increasing the diameter of the rim by about 1mm. So as free lunches go its more of a snack than a feast.

    Assuming a similar volume of material a rim without a hook will be stronger than a hooked rim. Not that the strength in this area contributes to any part of how the wheel handles, but it does allow for marginal weight saving if you remove it, or maybe you use that extra smidge of material to extend the vertical height of the sidewall to help keep those ''tricky'' kevlar beads on.

    One assumes LB have increased the OD of the rim ever so slightly to compensate for the lack of bead hook. In their favour is the fact that shallower tyre-lean-angles (over the rim) will occur due to the increased internal rim width. On balance rolling a tyre off the wider AM hookless rims doesn't strike me as being any more likely than it would be with a narrower hooked bead design.

    ..and that's why I bought a set...




    There are a few guys on here who are really trying to spread FUD about bike products sourced outside of the usual commercial channels. One can only guess at their motivation!

  33. #5133
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    Quote Originally Posted by Oaktree View Post
    after breaking a flow rim (not a Flow EX and not the rim's fault) I ordered up some LB, "new process", 29er, beadhookless, inner width 22mm, published weight 365g rims.

    I found lot's of people here with positive comments on wheel weight and stiffness with carbon so I did some measurements with the RIMS only. This doesn't translate directly to overall wheel stiffness, and I'm not sure how representative a lateral and then radial static force is of actual forces during mtn biking, but it is at least a quantitative data point that I didn't easily find elsewhere (searched, but didn't read entire thread here...).

    I weighed the rims using a gram scale and I measured the deflection by hanging an approximate 16 lb weight (see images)

    I'll list the data in the following order: rim type, measured weight, radial deflection, lateral deflection,

    DATA:
    FLOW, 535g, .070inch, .348inch
    LB, 363g, .048inch, .421inch

    In conclusion, my LB rims are 32% lighter, 21% less lateraly stiff, 31% more radially stiff. And I can't wait to lace them up!

    Click image for larger version. 

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    This makes me feel a tiny bit better about building a heavy Flow up, and I saved $170 on the wheel. I am fairly sure the 35mm carbon rims are going to be much more radially stiff than the Flows but the law of diminishing returns has probably kicked in at that point.

    As far as wheels being too stiff radially you would think it would be a huge issue with Road cyclist and their 120psi 23mm tires on deep rims, the whole "laterally stiff vertically compliant" marketing shenanigans may be at work here.

    This is a response from Bike Rumors comments section about the issue.

    "I can not believe Stan’s would make such bogus claims as the rim “absorbing radial vibrations” Not only does this violate physics and everything known about how bicycle wheels works"...
    " Anyone that thinks so can read numerous peer reviewed scientific papers that show radial wheel stiffness for ALL bike wheels (even those made to be flexy which apparently these are) are still way too stiff radially for any human being to be able to tell the difference."
    The wheel is a extension of the foot

  34. #5134
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    Quote Originally Posted by YaMon View Post
    Good argument, but I still feel that the parts add up to the sum.......start with a weak component vs. a stronger one and the results will be different. All I am saying is build a structure using weaker components and compare it to the exactly same structure built with stronger components and see what the results are .......will that 2" x 1/4" screw build a weaker structure that if it were bolted together with a 2" x 3/8" lag bolt ??? I don't know, but it sure does seem like it would, otherwise we would use 2" drywall screws....
    Individual elements have differing strengths when measuring flex in different directions. It could be that a rim that is radially stiffer but laterally more flexible then another rim, is actually laterally stiffer once built into a wheel. The question is, when built into a wheel, does radial rim stiffness translate into lateral stiffness? That is an important detail because your tests indicate that one rim is stronger radially and the other stronger laterally.

    It is also necessary to consider that when under weighted riding conditions, the spokes between the hub and the ground are not under tension and basically don't exist when calculating a force diagram. It is only the spokes under tensile load that contribute anything to the wheel's strength at any given time. (Edit: That is a horrible over simplification on my part. It is merely intended to show the complexity of trying to scientifically quantify wheel strength from a theoretical perspective.)

    It really is quite complicated and a bit above my level of education. There's tensile strength vs compressive strength to consider. With spokes and hub added, it could be that compressive load is replaced by tensile load. Or some such mumbo jumbo.

  35. #5135
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    The number of spokes is also at play.

  36. #5136
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    I get on my bike at 215 lbs and had built up my hardtail to be a reliable do-all bike (wide bars, dropper post, rock ring instead of large chainring, and the 2.4" tires with Stan's beefy Flow rims). Now with a new long travel 29er in my sites, I'll have the luxury of making the hardtail a pure cross country rig. Therefore when given the choice of LB rims, I took a chance getting the lighter ones.

    LB makes available their test results. I find their transparency refreshing. Their static load tests shows that for those extra 50 grams you get a huge 58% bump in strength (385 lbs to 609 lbs) by going with the 35mm hookless. Check with them for results on the heavier version of the "27W-24D" (22mm inner width) that I got.

    But, given that I sat on my Flow rim and bounced my weight and broke what I consider to be a very durable rim, then sat on my new LB and bounced (a super tiny little bounce with my fingers crossed) and it went no where near the 1.9" deflection at breakage that they publish, I'm confidence in the radial strength against static loads. If it breaks under CC riding it'll be some other deficiency which the heavier rim will likely share. That being said I don't expect to have anything but smiles with these rims. Now, if my new AM fully needs new rims one day I'd probably go for the heavier version, but for my riding the weight came first.

  37. #5137
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    Quote Originally Posted by YaMon View Post
    Cool test and simple enough for a lot of people to do....maybe we can come up with some standards to test other rims.....
    Even if not scientifically bulletproof, a standardized test would allow at least comparison of different rims, which is what I think most people are after anyway.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  38. #5138
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    Quote Originally Posted by meltingfeather View Post
    Even if not scientifically bulletproof, a standardized test would allow at least comparison of different rims, which is what I think most people are after anyway.
    It isn't just a question of being scientifically "bulletproof". The numbers might be so misleading that people would have a worse understanding of a rim's strength or stiffness.

    True, people would love to have an easily comparable numbers to assess wheel strength. The question is, are these numbers valid for that use? If radial stiffness translates into lateral stiffness once built as a wheel, the answer is likely no, the lateral stiffness of the rim alone is not indicative of the lateral stiffness of a wheel built with that rim.

    These things aren't always intuitive. For example, I have read that butted spokes make a more durable wheel than straight spokes. This is despite the butted spokes being thinner and easier to bend. That is a different phenomenon than the force transfer being discussed here. However it shows that focusing on an isolated statistic without understanding the entire system, can lead to a conclusion that is the exact opposite of reality.

  39. #5139
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    Quote Originally Posted by dfiler View Post
    It isn't just a question of being scientifically "bulletproof". The numbers might be so misleading that people would have a worse understanding of a rim's strength or stiffness.
    By this same argument, why measure the stiffness of a complete wheel, an isolated statistic? the wheel will always be put into duty as part of a bike, the complete system, so maybe the only measurements that mean anything and can't be misinterpreted should be of complete bikes. Think of the variables!!!
    Counter intuitive phenomena aren't limited to just the components of a wheel.
    Stiff wheels can cause more frame rub than flexy ones.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  40. #5140
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    funny, I considered taking deflection measurements by doing the whole wheel because I'm using the same spoke type and re-using the hub. But, realized that the variation in spoke tension between the used wheel and the new one I build (without tensiometer) could produce mis-leading results. Anyhow, like I said, I won't be surprised if they ride a little "stiffer"...and in a good way (sorry Stan).

  41. #5141
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    Quote Originally Posted by meltingfeather View Post
    By this same argument, why measure the stiffness of a complete wheel, an isolated statistic? the wheel will always be put into duty as part of a bike, the complete system, so maybe the only measurements that mean anything and can't be misinterpreted should be of complete bikes. Think of the variables!!!
    Counter intuitive phenomena aren't limited to just the components of a wheel.
    Stiff wheels can cause more frame rub than flexy ones.
    There is some truth to that but the effect is likely insignificant. Hopefully it is obvious that lacing a rim to a hub significantly effects stiffness. But really, I don't think you're actually trying to argue that point.

    [Edit: to clarify, I was theorizing that radial stiffness of a rim contributes greatly to lateral stiffness of a whole wheel]

    Quote Originally Posted by Oaktree View Post
    funny, I considered taking deflection measurements by doing the whole wheel because I'm using the same spoke type and re-using the hub. But, realized that the variation in spoke tension between the used wheel and the new one I build (without tensiometer) could produce mis-leading results. Anyhow, like I said, I won't be surprised if they ride a little "stiffer"...and in a good way (sorry Stan).
    Be sure to report back with your opinion! My prediction is that you will perceive them as stiffer laterally despite being less laterally stiff when measured as just a rim.

  42. #5142
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    (Cheap) Chinese Carbon Rims?

    Quote Originally Posted by dfiler View Post
    My prediction is that you will perceive them as stiffer laterally despite being less laterally stiff when measured as just a rim.
    Perception is the ultimate and unarguable variable. Introduce that and you've got to grow any measurement out the window.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  43. #5143
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    Since we have already detailed this thread........

    The Stan's video is hilarious. I really don't see why Stan's wouldn't source some Carbon hoops for their wheelsets.

  44. #5144
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    Quote Originally Posted by DeeZee View Post
    I really don't see why Stan's wouldn't source some Carbon hoops for their wheelsets.
    They have
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  45. #5145
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    My 29er wider rims arrived today 384 and 385 grams each. Quality looks good, Now to choose hubs any reason not to to get american classics? I'm using these wheels mainly for racing.

  46. #5146
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    (Cheap) Chinese Carbon Rims?

    Quote Originally Posted by Jon8500 View Post
    My 29er wider rims arrived today 384 and 385 grams each. Quality looks good, Now to choose hubs any reason not to to get american classics? I'm using these wheels mainly for racing.
    I think AmClassic hubs are excellent - light, tall flanges, reasonable price, can build wheels with 1 spoke length, very solid engagement, roll super smooth, easy to service and swap axle standards and freehub standards. There's nothing that beats them on those criteria. Only negatives are relatively low POE (to which I say don't stop pedaling), no centerlock option, no colors Some people post about reliability, but I've ridden the new ones through a winter of salted roads and found pristine internals at spring. I've shopped around and nearly bought Tune King/Kong, but decided it wasn't worth the $ and ?'s to save ~30 grams.
    M

  47. #5147
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    I love my AM hubs. The one size spoke just seals the deal.
    Full rigid SS, Hardtail SS, Hardtail Geared, Full Suspension Geared.

  48. #5148
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    Just got mine in today, they look great. Once I get some time I'll take them to the LBS and report back on the build.

  49. #5149
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    (Cheap) Chinese Carbon Rims?

    Quote Originally Posted by yourdaguy View Post
    I love my AM hubs. The one size spoke just seals the deal.
    This feature is the one differentiator am hubs have and it saves money when buying spokes.

    I used a donor set of older AC 350 hubs and they have been trouble free with no servicing needed over the last two years.
    Last edited by Adroit Rider; 01-31-2014 at 06:38 AM.

  50. #5150
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    I meant AC hubs-American Classic.
    Full rigid SS, Hardtail SS, Hardtail Geared, Full Suspension Geared.

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