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  1. #5301
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    Quote Originally Posted by eighty6gt View Post
    Just "built" some wheels with "wider 29"" light bicycle rims. Could not determine any handedness - rims seemed center drilled. Maybe the holes were angled but drilled on center, did not seem that way.

    Max tension is listed at 180 kgf. At 137 on park gauge the area around some of the spoke holes deformed. I hadn't intended on going tighter, they just seemed to be headed here and it's 22 on the gauge.

    I'd say stick around 100. Probably would have been fine. Many alu rims can handle 125, and I felt invincible with that stratospheric 180 kgf ceiling.
    So.... sounds like maybe you didnt read this thread?
    Put a mountain biker in a room with 2 bowling balls and we'll break one and lose the other - GelatiCruiser

  2. #5302
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    Quote Originally Posted by eighty6gt View Post
    Just "built" some wheels with "wider 29"" light bicycle rims. Could not determine any handedness - rims seemed center drilled. Maybe the holes were angled but drilled on center, did not seem that way.

    Max tension is listed at 180 kgf. At 137 on park gauge the area around some of the spoke holes deformed. I hadn't intended on going tighter, they just seemed to be headed here and it's 22 on the gauge.

    I'd say stick around 100. Probably would have been fine. Many alu rims can handle 125, and I felt invincible with that stratospheric 180 kgf ceiling.
    News I can use. Thx

  3. #5303
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    I also built w/ LB "wider 29" and they were straight drilled on the centerline.

    Their 180 max tension value is suspect to me. Certainly no one should consider building anywhere near that tension. Not that its even possible -- many spoke/nipple combos are going to have a very difficult time turning above 125kgf or so.

    I built mine to ~ 110kgf using a Wheelsmith tensiometer.

    Of all the "technologies" incorporated into these rims, I'm very frustrated that they don't embrace an asymmetric/offset design. I've had great experience w/ offset rims from Bontrager and Velocity. Significant benefit with little/no downside; doesn't seem like it would impact LB's manufacturing process too much.

  4. #5304
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    Very easy to tension to this and beyond. Nickel on threads and I lubed the nipple shoulders. Just built a 26" with a stans rim, came out perfect.

    I expect lb will warranty my rims since their specs are blatantly wrong. Haha. We'll see.

  5. #5305
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    (Cheap) Chinese Carbon Rims?

    ^^

    I'm pretty sure straight center drilling is not as difficult and expensive to do as having a jig for angled and offset drilling. All use right now is a simple straight forward jig. If they would buy or setup an angled and/or offset drilling jig, that would increase their cost and they would have to raise their prices. But I agree, angled drilling would be a big plus on these considering you have to deal with extra friction and bending on the spoke threads when building to high tension right now.

    Maybe if they get enough demand for it, they'll offer angled drilling at an additional cost ?
    Quote Originally Posted by NicoleB28 View Post
    topless. that's what all mtb girls do. we go ride, get topless, have pillow fights in the woods, scissor, then ride home!

  6. #5306
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    ^^

    I wasn't talking about angled drilling, or holes offset relative to other holes. I agree that such drilling would be more expensive/difficult than centered/perpendicular drilling.

    I was referring to holes (and rim cross section) being offset relative to the rim centerline. In this case, all the holes could still all be drilled on one "line" and perpendicular . . . its just that the line would not be centered on the rim. It would require a different mold so that the "peak" of the rim (where the holes are drilled) would be 2 to 4mm offset from center. But I don't see why that mold would be significantly more difficult or expensive to make than a typical symmetric one.

  7. #5307
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    (Cheap) Chinese Carbon Rims?

    I think each molds requires about 3-5 days of CNC and manual machining. Plus there wouldn't be enough demand for them to look into it (unfortunately), as for most the benefits and magic of offset rims isn't a concern. Also, wouldn't that offset be different upon each axle spacing ? A 135mm axle and a 142mm or 150mm would not require the same exact offset, or does the difference would not be significant to worry about it ?
    Quote Originally Posted by NicoleB28 View Post
    topless. that's what all mtb girls do. we go ride, get topless, have pillow fights in the woods, scissor, then ride home!

  8. #5308
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    Quote Originally Posted by David C View Post
    I think each molds requires about 3-5 days of CNC and manual machining. Plus there wouldn't be enough demand for them to look into it (unfortunately), as for most the benefits and magic of offset rims isn't a concern. Also, wouldn't that offset be different upon each axle spacing ? A 135mm axle and a 142mm or 150mm would not require the same exact offset, or does the difference would not be significant to worry about it ?
    The "optimal" offset would indeed vary between hubs, not necessarily due to OLD length, but due to flange spacing. My point is that a 150mm hub doesn't necessarily have wider flange stance (though in practice most do). But more to the point: the optimal offset isn't that important. My main point is that some offset is better than none. For wide-ish 30mm (outside) rims, a 3.5mm offset would be pretty straightforward to implement. And for the vast majority of builds, it would bring nearly identical spoke lengths plus much more equal bracing angles and tensions . . . all issues that are important enough to LB customers that they often get debated here ad nauseam.

    As for the mold times/costs, of course a NEW mold will have new/additional costs. They keep introducing new rims (the "new process" wider 29s, the bead hookless, etc) and each of them require molds. My point is that the design/mold costs for a new rim aren't really impacted by asymmetry, ie there isn't a downside. So why haven't they been doing asymmetric rims?

    In road rims I understand why not: people want a centered model for the front wheel. So going asym means an entire second set of molds. But in MTB, where all builds are disc, both the front and rear rims benefit from the same asym design. So why not be all asym instead of all symmetric??

  9. #5309
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    With 32 spokes offset rims don't add that much. Also, offset are heavier.
    Full rigid SS, Hardtail SS, Hardtail Geared, Full Suspension Geared.

  10. #5310
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    Quote Originally Posted by yourdaguy View Post
    With 32 spokes offset rims don't add that much. Also, offset are heavier.
    I'm not aware of any evidence to support either of those statements.

    Benefits of offset drilling are independent of the hole count; there is virtually no diminishing effect as the hole count increases. For example, using a shimano disc hub and a 603 ERD rim (= LB wider 29) laced 3X as an example:

    Relative NDS/DS tension on a symmetric rim:
    32H front = 143%
    24H front = 144%
    32H rear = 65%
    24H rear = 65%
    Relative NDS/DS tension on a 3.5mm asym rim:
    32H front = 114%
    24H front = 114%
    32H rear = 84%
    24H rear = 84%

    So the hole count is irrelevant to this specific topic. Regardless of hole count, you get the benefit of ~ 20% reduction in spoke tension "unequalness". One can debate if that 20% (and the associated improved bracing angle which influences wheel stiffness) is a worthwhile benefit. Personally I think its a significant benefit, and has the additional bonus of making a single spoke length viable for all four flanges in many hubsets.

    As for the weight issue, why do you think they are heavier? I can't think of any reason asym needs to be heavier. And if one compares weight of existing sym/asym models, the differences are negligible and go both ways:

    Velocity Synergy sym/asym = 490/490g
    Velocity A23 sym/asym = 450/460g
    Velocity Aerohead sym/asym = 405/400g
    Nox Composites asym carbon 30mm rim = 385g
    LB sym carbon 30mm = 390g (+/- 10g)

    Any weight deltas are less than typical rim-to-rim variance among a given model.

  11. #5311
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    The reason I say they are heavier is that when Shimano went to offset rear on some of their road aluminum rims the rear wheel gained over 50 grams.

    With 32 spokes you generally go to 3 cross and the cross bracing tends to negate any advantages of more symmetrical bracing. Take a rear MTB wheel that is 3 cross 32 spokes and clamp it into a frame without a tire and push to either side with equal force and you will find that there is very little difference in deflection.

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  12. #5312
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    For the record I took 1/2 turn out of the rear wheel and 1/4 out of the front, down to 110 kgf on the tight side on both wheels now. I suspect I'd have bulged spoke holes after some use whether I had them up as high as I did or not. Found another thread about manufacturing defects.

    If LB wants to send me some free hoops, great, otherwise I'll make sure my helmet is on and see what happens. Wish me luck! Saving so much money...

  13. #5313
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    Quote Originally Posted by yourdaguy View Post
    With 32 spokes you generally go to 3 cross and the cross bracing tends to negate any advantages of more symmetrical bracing.
    Again I don't find your point credible. Cross bracing negates advantages of symmetric bracing? If one actually measures it, number of crosses has very negligible impact on bracing angle. Laced 2X vs. 3X, the bracing angle changes less than 2%. Other lacing patterns (radial, 1X, 4X) are rarely used in disc wheels.

    Pushing a wheel clamped in a frame isn't exactly a precise measurement, but I'll accept your example, and I'll even accept the conclusion: a given amount of force will have essentially the same deflection on both sides of a given wheel, despite the spoke angles being substantially different. Well of course it does! That's because the horizontal component of the spoke tension force is essentially the same on both sides. The steeper angle (drive side) may have a higher tension, but less of it is directed in the horizontal dimension.

    That exercise does not actually illustrate your claim. What you should really be comparing is the deflection of one rim built symmetric and another rim built asymmetric, both with identical drive side spoke tension. And in that example, the asym wheel WILL have measurably less deflection. That's because the DS spokes on the asym wheel will have a higher horizontal force component than the sym wheel.

    Quote Originally Posted by yourdaguy View Post
    when Shimano went to offset rear on some of their road aluminum rims the rear wheel gained over 50 grams
    Certainly I could see how that might make one think that asym was the forcing factor on the weight. But this change may have correlated with their move to a UST rim profile. So the beefed up rim around the spokes may be the extra weight. At any rate, its hard to find perfect apples/apples comparison. Ultimately I still don't see any material reason they need to be heavier.

  14. #5314
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    No they didn't change to UST. The only apparent change was to the back rim. I have the Shimano "Trade Sales and Support" manuals from those years and the only apparent change was to the rear rim.

    If you can't see that a perfect arch is more efficient in material than a skewed arch, I can't help you.

    You are claiming that a non-symmetric rim should have less deflection overall and actually, if the overall bracing is similar then the non-symmetric rim should be equal on each side and the symmetric should be skewed to one side with less deflection in one direction and more in the other. This is the argument the Bill S makes for the AC design (which I like)

    So why is pushing a wheel clamped in a frame not a precise measurement? If I push it at the top, it represents the same thing that the ground pushing it at the bottom would do.
    I currently have a tire on my AC wheels, but I have done the same test and while the AC wheels are more symmetric, the difference is not enough in my opinion to be felt while riding. I love my AC wheels and they are my favorite, but this bracing angle thing is way overplayed, just like zero stack pedals and Q factor.

    Why does not the fact that my "exercise" that indicates almost no difference between the deflection left or right not "illustrate" my claim when building a similar wheel built to your specifications with an offset rim that would show a similar lack of difference of deflection illustrate your point?

    Your quote, to me, proves my point;
    Quote>>>
    I'll accept your example, and I'll even accept the conclusion: a given amount of force will have essentially the same deflection on both sides of a given wheel, despite the spoke angles being substantially different. Well of course it does! That's because the horizontal component of the spoke tension force is essentially the same on both sides. The steeper angle (drive side) may have a higher tension, but less of it is directed in the horizontal dimension.
    End Quote<<<

    So when we ride the bike and the deflection is almost the same, what is the advantage of the offset rim?????

    And by the way, I am not trying to be a "Dick", I am a very nice guy. But I don't like the bike industry trying to tell us why stuff that is not really better is better such as zero stack pedals, low Q factor cranks, PF30, PF90, don't get me started.
    Full rigid SS, Hardtail SS, Hardtail Geared, Full Suspension Geared.

  15. #5315
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    Back in the day asym rims cracked all the time so for us old dudes, meh. Pure guessing here but it probably puts an uneven load on the rim and creates its own weakest link. Another guess here; all the other manufacturers know this and stay away since it would make for a heavier rim except for the ones that need a gimmick to market their products. And us mtn bikers are suckers for "visible technology" (its a marketing term).
    Quote Originally Posted by yourdaguy View Post
    ...And by the way, I am not trying to be a "Dick", I am a very nice guy. But I don't like the bike industry trying to tell us why stuff that is not really better is better such as zero stack pedals, low Q factor cranks, PF30, PF90, don't get me started.
    Rule #42: Pick a BB standard and be a DICK about it.

  16. #5316
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    Here comes a long one . . .

    Quote Originally Posted by yourdaguy View Post
    If you can't see that a perfect arch is more efficient in material than a skewed arch, I can't help you.
    Its not that I can't see it. Its that the difference is insignificantly small. I understand that an offset arch will have a slightly longer arch length than a symmetric arch. But how much longer? Using triangulation since I don't have matlab at my disposal right now, the additional length is something on the order of 0.3 to 0.4% assuming a rim with cross-section dimension similar to LB wider 29er. Now consider that the majority of the material (60%+) is actually in the main bed and sidewalls, which are unrelated to the arch symmetry, so the overall "increase" in the material for an offset rim is further reduced to 0.1 to 0.2%. This is INSIGNIFICANT compared to the primary determinants of material weight such as overall layup (or extrusion thickness if alloy), rim depth, rim width, bead vs beadless, etc.

    Quote Originally Posted by yourdaguy View Post
    You are claiming that a non-symmetric rim should have less deflection overall
    Not exactly. I'm noting a well proven fact that, all else equal, higher bracing angles equate to higher lateral stiffness (less lateral deflection) and pointing out that an asym rim enables higher spoke bracing angles for the limiting flanges (drive side rear or rotor side front). This is pretty simply trigonometry.

    Quote Originally Posted by yourdaguy View Post
    and actually, if the overall bracing is similar then the non-symmetric rim should be equal on each side and the symmetric should be skewed to one side with less deflection in one direction and more in the other. This is the argument the Bill S makes for the AC design (which I like)
    Virtually any bicycle wheel built to reasonable tension will have virtually equal lateral deflection to both sides. This is intuitive from the math, but it has been demonstrated empirically here:
    Wheel Stiffness Test

    Quote Originally Posted by yourdaguy View Post
    So why is pushing a wheel clamped in a frame not a precise measurement?
    Your fingers can consistently distinguish and record deflection differences of tenths of a mm while pressing on them with 25 pounds of force??
    Lateral deflection is a legitimate measurement. But it requires a rig and high precision tools to measure, not fingers. (see URL above for an example of such a rig).

    Quote Originally Posted by yourdaguy View Post
    this bracing angle thing is way overplayed, just like zero stack pedals and Q factor.
    Zero stack pedals and q-factor both deeply involve physiology that is far more complex (and different from person to person) than the simple trigonometry of spoke angles. While I share your skepticism toward those topics, I wouldn't even remotely equate them to spoke bracing angle.

    Quote Originally Posted by yourdaguy View Post
    Why does not the fact that my "exercise" that indicates almost no difference between the deflection left or right not "illustrate" my claim when building a similar wheel built to your specifications with an offset rim that would show a similar lack of difference of deflection illustrate your point?
    Your exercise is an example of a known fact: that wheels don't defect with any meaningful difference from one side to another of a given wheel. Your exercise with wheel A has no direct relevance to the deflection of a second (asym) wheel B built with different bracing angles. Will wheel B also have equal deflection to both sides? Yes, of course. But will the deflection of wheel A be equal to the deflection of wheel B? NO!!

    The experiment we need is a comparison in deflection of two different wheels, using rims that are identical other than the sym/asym spoke bed, and built with identical drive side spoke tension. Although that exact experiment isn't shown at Rinard's URL above, his experiments with front versus rear wheels are a suitable proxy and clearly indicate that increased bracing angles provide measurable improvement in stiffness/deflection. Math alone indicates 15-20% improvement (asym vs. sym) in deflection. Rinard's empirical front/rear tests are consistent with this (he found front/rear deflection differences of 40-60%; if you correct for the less extreme difference in sym/asym bracing angles, 15-20% is spot on).

    Quote Originally Posted by yourdaguy View Post
    So when we ride the bike and the deflection is almost the same, what is the advantage of the offset rim?????
    Valid point. Its your choice to decide if ~15% improvement in deflection is meaningful to you. Just as it is my choice to decide if 0.15% increase in material mass in meaningful to me.

    Quote Originally Posted by yourdaguy View Post
    And by the way, I am not trying to be a "Dick", I am a very nice guy. But I don't like the bike industry trying to tell us why stuff that is not really better is better such as zero stack pedals, low Q factor cranks, PF30, PF90, don't get me started.
    I totally do NOT think you're being d1ckish. But I'm amused that you were concerned about it! I was also concerned I sounded d1ckish. But I haven't seen any name calling, just relatively friendly (for this site) debate.
    I've had my own battles with PF30, so I share that disdain. But I don't equate it to asym spoke beds. Its not like asym spoke beds create any compatibility issues or cause creaking!

    My overall point: asym spoke beds have modest but meaningful benefits, and relatively insignificant downsides. Its a rare case in cycling of getting something nearly for free. So I'm confused/frustrated that it isn't offered by LB. I'm trying to learn why. Because LB is somewhat passive and the market isn't loudly demanding it? Because of patents (though I couldn't find any after extensive searching)? Or because the rim cross section of these carbon rims begin to dominate the lateral stiffness equation to such a degree that bracing angles are playing a lesser and lesser role? My bet is the former (passive engineering & poor consumer awareness).

    I can always buy the Nox rims, but at more than 2X the price, I'm hesitant. As much as I'm a fan of asym, an asym spoke bed isn't worth $200 extra per rim to me!!

  17. #5317
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    Nice post inertia man.

    You can also buy european rims. A lot of rim manufacturers are doing assymetric rims here, for example Mavic in aluminium, or DukeWheels in carbon.
    Frenchspeaking 29"ers community site http://VingtNeuf.org

  18. #5318
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    Anyone post pics of the 30mm internal rim?

  19. #5319
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    Quote Originally Posted by GTR-33 View Post
    Anyone post pics of the 30mm internal rim?
    There are a bunch of pics posted in here...if you go back to p209, I have pics of the ones I purchased from LB that are AM 30mm internal wide rims.
    "By Your Command"

  20. #5320
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    Note that people have different page numbers due to the configurable setting for number of posts per page. For example, this post is on page #178 for me.

    Post number references work for everyone though.

  21. #5321
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    LB is warrantying my rims because of the nipple bulge issue. They asked for photos and the serial #'s, I sent them, and they got back to me in 1 day.

    Pretty happy about that. Hope the new ones are indestructible as advertised.

  22. #5322
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    After going back and forth so many times that I lost count, I finally broke down and ordered a pair of LB XC hookless rims..They weren't in stock and said the lead time is 7-14 days. I guess the waiting game has begun. Of course once I lace them up, I'll have a better idea if it's a great upgrade or a headache. Fingers crossed they take extra special care building mine....

  23. #5323
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    Quote Originally Posted by eighty6gt View Post
    LB is warrantying my rims because of the nipple bulge issue. They asked for photos and the serial #'s, I sent them, and they got back to me in 1 day.
    Pretty happy about that. Hope the new ones are indestructible as advertised.
    How old were your previous ones? I read here (this or another thread) that the listed spoke tensions are not to be followed (something like 130 to 180 kgf?). A guy was saying that as he while he was building his he could see the spoke bed deforming. I think someone else chimed in saying 100kgf was fine with his build. I personally don't trust myself to build these wheels but when I bring them to 'my wheel guy' I will certainly be telling him my concerns due to others experience so he does not follow a listed tension and damage the rim.
    Regardless, good luck. I hope you your new rim shortly (and the other does not fail).
    Mine (29er 35mm Hookless DH) should be here next week and built up shortly there after so I will post them up when finished.

  24. #5324
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    (Cheap) Chinese Carbon Rims?

    Quote Originally Posted by S.O.B. View Post
    I personally don't trust myself to build these wheels but when I bring them to 'my wheel guy' I will certainly be telling him my concerns due to others experience so he does not follow a listed tension and damage the rim.
    He should know that already.
    There is no reason to build 32h wheels to that kind of tension.
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    Time to stop believing the hype and start doing some science.
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  25. #5325
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    I fell down out of ignorance. The scientist in me determined that high tension means a stronger wheel. I don't even need strong wheels, but I thought I'd try winding them up as an experiment - without benefit or merit, but why not see if there was some difference running 30% more tension. Seemed reasonable given the ratings of good aluminum rims. Luckily, I have the time and money for this.

    Do not fear building wheels, or doing anything. It is often from experience that people like meltingfeather know what they do now.

    My wheels that bulged were built in January, as far as I can determine.



    Quote Originally Posted by S.O.B. View Post
    How old were your previous ones? I read here (this or another thread) that the listed spoke tensions are not to be followed (something like 130 to 180 kgf?). A guy was saying that as he while he was building his he could see the spoke bed deforming. I think someone else chimed in saying 100kgf was fine with his build. I personally don't trust myself to build these wheels but when I bring them to 'my wheel guy' I will certainly be telling him my concerns due to others experience so he does not follow a listed tension and damage the rim.
    Regardless, good luck. I hope you your new rim shortly (and the other does not fail).
    Mine (29er 35mm Hookless DH) should be here next week and built up shortly there after so I will post them up when finished.

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