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  1. #1
    dwt
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    Giant's marketing math

    Lotta controversy in the forums about this. Seems to have lit a new spark in the "27.5" is all about marketing" line of hate.

    Giant has gone all in as far as production, but have they gone over the line as far as marketing?

    I'm no physicist, engineer or mathematician, so have no ability to analyze it.

    So, whether lover or hater, does anybody have any grounded in fact rebuttal, or for that matter, confirmation?

    The Case for 27.5

    * All else being equal, a 27.5-inch wheel is 5 percent heavier than a 26-inch wheel, but 7 percent lighter than a 29er. * A 27.5-inch wheel's angle of attack is 4 percent better than a 26-inch wheel. A 29erís angle of attack is only 2 percent better than a 27.5. * Comparing acceleration rates (or moment of inertia), 27.5 wheels are 1.5 percent slower than 26-inch wheels. Wheels with 29-inch diameters are 2.1 percent slower than 27.5 wheels. * The contact patch on 27.5 wheels is 2cm larger than on 26-inch wheels. The patch is only larger on 29ers than on 27.5 wheels. (Giant is the only company we know of currently saying that bigger wheels have larger contact patches; most companies state larger wheels have longer and narrower contact patches than a smaller wheel, but that the total contact area does not increase with a larger wheel.)

    Giant also studied how wheel size affects other parts of the bike, like geometry and frame stiffness. They found that frames built around 27.5 wheels are two percent less stiff than those for 26-inch wheels, but 3.5 percent stiffer than 29er frames. The research also revealed that compared to 29er wheels, the slightly smaller 27.5 wheels can help reduce stem stack heights, create fewer issues with toe overlap and lead to frame geometry that better fits smaller riders.
    http://m.bicycling.com/mountainbikec...75-inch-wheels
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  2. #2
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    I stopped at "marketing". Marketing in general is...
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  3. #3
    AZ
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    I don't ride marketing.

  4. #4
    dwt
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    Giant's marketing math

    Quote Originally Posted by Dirty $anchez View Post
    I don't ride marketing.
    How about MTBR buzz? Immune from that too?

    We live in a capitalist society that runs on marketing. We're stuck with it, but free to ignore or listen, or maybe not
    so free depending on subliminal effects

    Giant's marketing almost looks Steve Jobs worthy in audacity and intensity. The question for me is whether it is true or false, or how truthy and how falsy.

    Example: I now own iPhone and iPad. Didn't use to own Apple products, but marketing made or influenced by Jobs musta got me. Glad it did, cuz now I love Apple products; really superior in many ways. The marketing was truer than false, IMO.

    I'd like to know from an independent and reliable source about 27.5". If such a source exists. Doubtful on MTBR where everybody drinks some kind of kool aid, even those who think and say they don't. That's its own flavor.
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  5. #5
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    I have not done the math, but I would be surprised if they were fudging the numbers. Too easy to refute them since they are very easy measurements.

  6. #6
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    Asking a bunch of MTBers on the 650b/27.5 will only get you the answer you want to hear. If you want serious data then you should ask this question on Quora and maybe you'll get a real physicist/engineer to answer these questions.

    For me, it's pretty obvious. It's really up to the rider to decide what is most important to them because after all everything is just a compromise.
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  7. #7
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    I will just chime in briefly - "angle of attack" WRT wheels just means you need to know how high the axle is, and how high the obstacle is (assuming a round wheel). So it's not a fixed number for ANY wheel size. If you're rolling into a brick wall, the angle of attack is 90 degrees (or zero if you want to think of it that way) on any wheel, and if you're rolling over a grain of dust it's basically zero (or 90).

    I guess what I'm saying is that I don't understand how Giant is using that term, since angle of attack depends not just on the wheel but on the trail obstacle (or lack thereof).

    The contact patch thing is bogus. It's well understood that the patch changes *shape* but not size as you increase diameter (ie bigger wheels make a longer and narrower contact patch). Whether the 27.5 contact patch shape is superior is open to debate of course.

    Weight is noncontroversial and Giant is completely correct.

    Stiffness numbers are probably basically true comparing apples to apples for both wheels and frames (ie bigger wheels and frames are less stiff). But modern frames are crazy stiff so 2% one way or the other probably isn't something that anyone can perceive, nor will it make a difference on the trail. I could go on a long rant about the limits of stiffness, or the absurdity of selectively using absolute and relative figures, or any number of other things here but I'll spare everyone the angst.

    Moment of inertia WRT wheels is again well understood. Bigger wheels accelerate slower - but they are only a small fraction of the mass you need to move to make the bike+you go, so that's also going to end up well below the threshold of detectability outside of a lab.

    I don't know what "research" was necessary to figure out that smaller wheels = lower stack heights, less toe overlap, better fit for smaller riders. It's sort of embarrassing to even use the word "research" in that context if your business is building bikes, IMO.

    I think the bottom line is that it's great marketing but mediocre to laughable "research".

    Also 650b rocks and I just finished building one so I've got no particular axe to grind on this.

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  8. #8
    AZ
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    Quote Originally Posted by dwt View Post
    How about MTBR buzz? Immune from that too?



    Yep. I may be the odd man out but I let the demo's decide. You know what I'm talkin about, you ride a bunch of them until you find the one that feels just right. You get to ride bikes too.

  9. #9
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    It's just personal preference...for me, 26" wheels (10 years) never felt right maybe b/c I'm tall or because I ride on the road and fire roads quite a bit...29ers (4 years) felt like I was riding a couch...so for me the inbetween size feels great. (Also I like the versatility as I have one bike but have a 2nd 29er wheelset that I use to ride on the road, gravel grinders, and cyclocross that fits in my 650b frame just great).

    But if you have a bike you already like, why switch? Just ride the bike you have and forget it. My friend has a 26" moots ybb which he loves and he's thinking of selling it. I've been trying to talk him out of it.

  10. #10
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    The problem is that all that math is nice, but math does not make a ride. It is tough to compare gains in angle off attack and counter the weight impact.

    Look 29ers have certain advantages to 26 on paper and well as the opposite. 27.5 is somewhere in between both and all of Giant's math just confirms that. What their math cannot do is determine if the 27.5 side overall better than both 26 and 29 over all conditions combined.

    Clearly they have made the choice to push 27.5 wheels. Some of this certainly due to marketing what they perceive as bringing the company money. However there also must be some level truth in their belief as if the bikes don't ride well wit 27.5 size they will not get the sales either. So far most what I have seen is that 27.5 are considered at least as good as 26" wheels and some consider them better than 29ers. The biggest argument against the 27.5 wheel seems to be that it rides like a 26er which is not that bad consider many people have ridden 26ers with good success. There are however people that have real complaints about 29ers so while some love them others hate them. It remains to be seen what happens with this wheel size. Last summer 27.5 was still limited to a few select frames and early adopters. Now with Giant going this way 27.5 is being pushed mainstream. The question is however will it stay there?
    Joe
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  11. #11
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    Quote Originally Posted by mforness3000 View Post
    ...so for me the inbetween size feels great.
    Hey! Marketing! It is working if you think it's truly in between!

  12. #12
    LMN
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    I have not really analyzed it or measured it but their marketing math is probably correct. The length of contact patch and angle of attack are not linear relationships with wheel diameter. As a wheel diameter increases the percentage change in those two variables decreases.
    "The best pace is suicide pace, and today is a good day to die." Steve Prefontaine

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    I just Ridezum.

  14. #14
    JCL
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    650b is the marketing size. I just see it as 26" plus from manufacturers who missed the 29" train. Nothing wrong with it but there was nothing wrong with 26".

  15. #15
    dwt
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    Giant's marketing math

    Quote Originally Posted by GSJ1973 View Post
    Hey! Marketing! It is working if you think it's truly in between!
    Obviously and factually it's in between. That is simple reality and has nothing to do with marketing. The marketing is that it is exactly half way in between. So what's your point?
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  16. #16
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    Giant's marketing math

    Quote Originally Posted by Ridezum View Post
    I just Ridezum.
    So should anyone who wants to have an informed and relevant opinion about it.
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  17. #17
    dwt
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    Giant's marketing math

    Quote Originally Posted by JCL View Post
    Nothing wrong with it but there was nothing wrong with 26".
    27.5" and 29" wheels are to mtb what oversize rackets are to tennis and oversize clubs are to golf.
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  18. #18
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    Quote Originally Posted by dwt View Post
    Obviously and factually it's in between. That is simple reality and has nothing to do with marketing. The marketing is that it is exactly half way in between. So what's your point?

    My point is it isn't exactly half way in between!!!

    26" - 2114 mm
    650 - 2193 mm = 3.5% bigger than 26"
    29" - 2312 mm = 9% bigger than 26"

  19. #19
    dwt
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    Giant's marketing math

    Quote Originally Posted by GSJ1973 View Post
    My point is it isn't exactly half way in between!!!

    26" - 2114 mm
    650 - 2193 mm = 3.5% bigger than 26"
    29" - 2312 mm = 9% bigger than 26"
    SFW? Who in this thread says it was? Who are you arguing with? Has Giant made the claim? What difference does it make anyway? WFC?
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  20. #20
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    Going to be interesting to see what Specialized, Trek and Cannondale does next year...

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    Quote Originally Posted by dwt View Post
    27.5" and 29" wheels are to mtb what oversize rackets are to tennis and oversize clubs are to golf.
    And I for one dont think oversized rackets make tennis any less difficult or fun, nor do oversized heads make golf any less boring.
    GIS/GPS Pro using ArcFM for Utility Mapping - Always willing to connect with other MTBers in the industry.

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    Okay, just a minute let me check my mumbers against Giants, yep they are correct. If only Specialized had the balls to publish stuff like this, I thinks it's pretty awesome for them to share the 'why' they are moving in this direction. I want Specialized to publish the numbers for 'why' they are not onboard.

    Isn't it all marketing, I get this ad on the top of my page for Orbea bikes, it's for an Occam or something, the marketing line is "ride fast on 'any' terrain". I don't know, the bike looks like a 29 xc bike, what does any terrain mean?, any terrain means any terrain doesn't it. I'm not doing a downhill run on it.

  23. #23
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    Quote Originally Posted by dwt View Post
    27.5" and 29" wheels are to mtb what oversize rackets are to tennis and oversize clubs are to golf.
    That's not really correct. The tennis companies never said we aren't making mid-size or mid plus anymore.
    However they did try to make 27.5" tennis rackets , claiming the leverage gained would increase your ball speed.
    I think Michael Chang was the only pro that used it.

  24. #24
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    The problem I have with the Giants marketing is that it doesn't make sense:
    They claim that bigger wheel size equals better traction?
    That's a function of tires , not wheels.
    They claim that better roll over gives you better cornering?
    I am not sure how that works, since most corners are not full of rocks and roots.

  25. #25
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    Quote Originally Posted by saidrick View Post
    I am not sure how that works, since most corners are not full of rocks and roots.
    Ever been to Blue Mound State Park, WI?
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    Quote Originally Posted by dwt View Post
    SFW? Who in this thread says it was? Who are you arguing with? Has Giant made the claim? What difference does it make anyway? WFC?

    I've quoted above who said it was in between. I have no idea what WFC or SFW is, sorry.

    Giant has made the claim, their math and marketing materials are very misleading.

    They claim "total bike weight up to two pounds less than a comparable 29er" and "will be the end-all wheels size" and "rolls over similar to a 29er" and "stiffer frame resulting in better handling than 29er frameset" etc. etc.

    I think this might be true comparing one of their own stock 27.5 bikes against their own stock 29er. When you start going across different brands though, then this is false. For instance, maybe a Specialized 29er at the same price point comes in lighter than a Giant 27.5 of the same price point.

    I currently ride a Nomad and my friend just got a Bronson which I have spent several rides on now comparing the two. In no way is it "in between" a 26 and 29. What Giant is publishing makes it seem like it's in between two wheel sizes and rolls over stuff more like a 29er than a 26er. Which is absolutely 100% not true (in my opinion) after several hours of good long rides on a Bronson.

    You started the thread and are poking at the bees nest! Be ready for the opinions!

  27. #27
    dwt
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    Giant's marketing math

    Quote Originally Posted by GSJ1973 View Post
    I've quoted above who said it was in between. I have no idea what WFC or SFW is, sorry.

    Giant has made the claim, their math and marketing materials are very misleading.

    They claim "total bike weight up to two pounds less than a comparable 29er" and "will be the end-all wheels size" and "rolls over similar to a 29er" and "stiffer frame resulting in better handling than 29er frameset" etc. etc.

    I think this might be true comparing one of their own stock 27.5 bikes against their own stock 29er. When you start going across different brands though, then this is false. For instance, maybe a Specialized 29er at the same price point comes in lighter than a Giant 27.5 of the same price point.

    I currently ride a Nomad and my friend just got a Bronson which I have spent several rides on now comparing the two. In no way is it "in between" a 26 and 29. What Giant is publishing makes it seem like it's in between two wheel sizes and rolls over stuff more like a 29er than a 26er. Which is absolutely 100% not true (in my opinion) after several hours of good long rides on a Bronson.

    You started the thread and are poking at the bees nest! Be ready for the opinions!
    The thread is about Giants marketing claims.

    3 is between 1 and 10, so is 5. 5 is half way between. The other poster never said half way. I don't know that Giant does either. If they do, please link.

    I think it has been resolved that a 650b wheel is not half way between 26 and 29 whether you use rim measurements or measurements with tires mounted. Using the latter this is because 26" wheels generally always measure larger than 26", whatever tire or rim is used.
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  28. #28
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    Quote Originally Posted by Walt View Post
    I will just chime in briefly - "angle of attack" WRT wheels just means you need to know how high the axle is, and how high the obstacle is (assuming a round wheel). So it's not a fixed number for ANY wheel size. If you're rolling into a brick wall, the angle of attack is 90 degrees (or zero if you want to think of it that way) on any wheel, and if you're rolling over a grain of dust it's basically zero (or 90).

    I guess what I'm saying is that I don't understand how Giant is using that term, since angle of attack depends not just on the wheel but on the trail obstacle (or lack thereof).

    The contact patch thing is bogus. It's well understood that the patch changes *shape* but not size as you increase diameter (ie bigger wheels make a longer and narrower contact patch). Whether the 27.5 contact patch shape is superior is open to debate of course.

    Weight is noncontroversial and Giant is completely correct.

    Stiffness numbers are probably basically true comparing apples to apples for both wheels and frames (ie bigger wheels and frames are less stiff). But modern frames are crazy stiff so 2% one way or the other probably isn't something that anyone can perceive, nor will it make a difference on the trail. I could go on a long rant about the limits of stiffness, or the absurdity of selectively using absolute and relative figures, or any number of other things here but I'll spare everyone the angst.

    Moment of inertia WRT wheels is again well understood. Bigger wheels accelerate slower - but they are only a small fraction of the mass you need to move to make the bike+you go, so that's also going to end up well below the threshold of detectability outside of a lab.

    I don't know what "research" was necessary to figure out that smaller wheels = lower stack heights, less toe overlap, better fit for smaller riders. It's sort of embarrassing to even use the word "research" in that context if your business is building bikes, IMO.

    I think the bottom line is that it's great marketing but mediocre to laughable "research".

    Also 650b rocks and I just finished building one so I've got no particular axe to grind on this.

    -Walt
    Correct on all accounts, Walt. I'm very surprised (dismayed) that they got the contact patch info incorrect.
    Tire Design & Development Engineer. The opinions expressed in this forum are solely my own.

  29. #29
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    [QUOTE=GSJ1973;10593637]My point is it isn't exactly half way in between!!!

    no sh!t

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    Quote Originally Posted by PHeller View Post
    And I for one dont think oversized rackets make tennis any less difficult or fun, nor do oversized heads make golf any less boring.
    Oversize rackets are great for tennis, however they really apply to this argument because most pro's don't use them. Agassi and his Head Radical are the exception.
    Sampras used a tiny racquet( 85vs 95/98 vs 110 sq. inches) that he wrapped with lead tape.

    But tennis is different, if a pro doesn't want to use his sponsors equipment, he just paints his old racquets to look like it.

  31. #31
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    What I don't get is why some are so butt-hurt over the "marketing" aspect of what Giant is doing. Why does it bother you so much? If you know (think) it is "marketing hype", then move along, nothing to see here, buy the brand that you think isn't marketing you in one way or another. People have the option to buy what they want to and ride what they want to, and companies can produce what they want to as well. Get over it.

    Personally for me, I am certainly looking into a 27.5 because some of the benefits make sense to me and the trails I ride. I also understand as I read the ad from Giant that it is marketing (is an f-ing ad, after all), and that the numbers certainly are presented in a way that sells bikes. I get it, read trhrough the so-called hype, and made me decision to look further into it.

    At least they put some numbers to it, which is plenty more than some companies have done, whether pushing 27.5 or deciding to stay out of it (Specialized). Jeez, you guys make it sound like the old Rogaine commercial that I used to laugh about where a guy asked his buddy how it worked......

    "Rogaine goes right to the root of the hair, and for some people, gets it to grow." *Now that is science and research right there!

    Oh, and for reference, here is the ad that some are so butt-hurt over:



    - 2014 Giant Trance 27.5 1
    - 2016 Transition Patrol Carbon (Ordered)

  32. #32
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    Quote Originally Posted by saidrick View Post
    They claim that bigger wheel size equals better traction?
    That's a function of tires , not wheels.
    They claim that better roll over gives you better cornering?
    I am not sure how that works, since most corners are not full of rocks and roots.
    In this comparison, tires have nothing to do with the traction difference between the sizes. The tire design should be held as a constant. What is different is the shape of the contact patch of the tire as a result of the size of the wheel (rim and tire). As pointed out earlier in this thread, contact patch area should not vary much if any, but the shape does and this is what changes the characterisitcs of the wheel size. The larger wheel will have a longer contact patch. This tends to give better traction and more stability in cornering.

  33. #33
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    Quote Originally Posted by Walt View Post
    I will just chime in briefly - "angle of attack" WRT wheels just means you need to know how high the axle is, and how high the obstacle is (assuming a round wheel). So it's not a fixed number for ANY wheel size. If you're rolling into a brick wall, the angle of attack is 90 degrees (or zero if you want to think of it that way) on any wheel, and if you're rolling over a grain of dust it's basically zero (or 90).

    I guess what I'm saying is that I don't understand how Giant is using that term, since angle of attack depends not just on the wheel but on the trail obstacle (or lack thereof)-Walt
    I think where you're running astray is that the trail obstacle is a constant. Given a constant obstacle, a larger diameter wheel will roll over the obstacle with less effort. Using your analogy above, if a wheel has a radius of 20 inches and you approach a brick wall that is 20 inches, your "angle of attack" is 90 degrees. If your wheel has a 40 inch radius, the angle of attack on the same wall would be 45 degrees. It's the relative size of the obstacle to the wheel that matters.

  34. #34
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    Quote Originally Posted by GSJ1973 View Post
    I've quoted above who said it was in between. I have no idea what WFC or SFW is, sorry.
    So f'ing what and who f'ing cares...does that help?

    Quote Originally Posted by GSJ1973 View Post
    Giant has made the claim, their math and marketing materials are very misleading.

    They claim "total bike weight up to two pounds less than a comparable 29er" and "will be the end-all wheels size" and "rolls over similar to a 29er" and "stiffer frame resulting in better handling than 29er frameset" etc. etc.

    I think this might be true comparing one of their own stock 27.5 bikes against their own stock 29er. When you start going across different brands though, then this is false. For instance, maybe a Specialized 29er at the same price point comes in lighter than a Giant 27.5 of the same price point.
    Why would you even think of comparing two different bikes when trying to compare a difference in wheel size? That makes no sense at all. Giants claim on this one is spot on. Given the same frame type and build, there is a difference in weight and stiffness. This is perfectly valid...your comparison is not.

    And as pointed out, saying the wheel size is not in between is incorrect. Nobody is saying it is half way between.

  35. #35
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    Quote Originally Posted by saidrick View Post
    The problem I have with the Giants marketing is that it doesn't make sense:
    They claim that bigger wheel size equals better traction?
    That's a function of tires , not wheels.
    They claim that better roll over gives you better cornering?
    I am not sure how that works, since most corners are not full of rocks and roots.
    This post couldn't be more wrong.

  36. #36
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    Quote Originally Posted by Walt View Post
    The contact patch thing is bogus. It's well understood that the patch changes *shape* but not size as you increase diameter (ie bigger wheels make a longer and narrower contact patch). Whether the 27.5 contact patch shape is superior is open to debate of course.

    Contact patch does increase in size as wheel diameter increases. It doesn't get wider, but it gets longer. It doesn't get narrower. I can't even figure out why you would say that. The surface area in contact with the ground increases. That's not debatable.

    Moment of inertia WRT wheels is again well understood. Bigger wheels accelerate slower - but they are only a small fraction of the mass you need to move to make the bike+you go, so that's also going to end up well below the threshold of detectability outside of a lab.

    It's rotating mass. It's definitely noticeable. At least compared to a hundred grams on a seatpost, for example.

    I don't know what "research" was necessary to figure out that smaller wheels = lower stack heights, less toe overlap, better fit for smaller riders. It's sort of embarrassing to even use the word "research" in that context if your business is building bikes, IMO.

    Well, a lot of companies have been putting a lot of research into making small frames with 29" wheels. If it was so obvious that it wouldn't work well, why did those companies do the research?

    -Walt
    Just a few thoughts.

  37. #37
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    I think the initial 27.5 to Apple comparison is excellent--Apple has always made rather overpriced mediocre hardware coupled with inaccurate or downright false marketing engineered and targeted to the privileged and trendy. But who cares about all that, they're cool!


    IMHO, to call what Giant is pushing 'R&D', 'math', or 'fact' is rather generous.

  38. #38
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    Quote Originally Posted by michael9218 View Post
    In this comparison, tires have nothing to do with the traction difference between the sizes. The tire design should be held as a constant. What is different is the shape of the contact patch of the tire as a result of the size of the wheel (rim and tire). As pointed out earlier in this thread, contact patch area should not vary much if any, but the shape does and this is what changes the characterisitcs of the wheel size. The larger wheel will have a longer contact patch. This tends to give better traction and more stability in cornering.
    You would think that tires have nothing to do with it, but why are some tires better in some sizes , instead of all sizes?

    Further more I have experienced too much traction with my 26" bike . And too little , both issues fixed by changing tires.
    My old Ventana was too slow with super glue kenda nevegals
    and my mojo was too slippery with the junk specialized XC tires it came with .

  39. #39
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    These threads are hilarious. Shouldn't everyone be happy that we now have more sizes to choose from? Look at the winter sports industry; there's a different sized ski from 60mm all the way up to 140+mm... and instead of complaining that one size is best, skiers just pick what's right for them and go with it. Pick the wheel size that's right for your type of riding and don't worry what other people think. Additionally, if you feel the need you can also adjust between 26", 650B, and 29" sizes by getting a bigger (or smaller) tire to ride.

    And in the effort of full disclosure, I have a 650b bike (converted 26" Blur LT frame) and a 29er (SC Superlight 29).

  40. #40
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    -Contact patch does not change much in area. You can easily prove this to yourself with some experimentation (identical tires/pressure on different size rims, some water or ink, piece of paper) but it's not controversial.

    -If you can come up with a way to detect a 100g change in ANY component when riding a vehicle that weighs ~90,000g (one tenth of one percent!) more power to you! Once again, the moment of inertia higher for bigger wheels but the wheels are a tiny part of the big picture.

    -I think you misunderstand. "Research" implies testing hypotheses and doing science. There is no "research" needed to state that a 300 pound person won't fit well into a size 3 dress because it's obvious, so saying that smaller wheels make can stack heights lower is silly. Of course they do, and that's a great thing if you need a lower stack height than you can get on a bigger wheel bike. Giant is totally correct, but they described their conclusions in a silly way.

    -Walt
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  41. #41
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    Quote Originally Posted by dwt View Post
    The thread is about Giants marketing claims.

    3 is between 1 and 10, so is 5. 5 is half way between. The other poster never said half way. I don't know that Giant does either. If they do, please link.
    hmmm. post #15 by you was a little confusing:

    "The marketing is that it is exactly half way in between. So what's your point?"

    I think it has been resolved that a 650b wheel is not half way between 26 and 29 whether you use rim measurements or measurements with tires mounted. Using the latter this is because 26" wheels generally always measure larger than 26", whatever tire or rim is used.
    anyway. glad thats resolved.

    i still dont understand giants angle of attack claims. A wheel that is closer to 26 somehow rolls closer to 29. Just doesnt make sense to me.

  42. #42
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    Aren't those pictures almost exactly the same as what Norco used in their big marketing presentations when they first introduced their 27.5 line a year or two ago? I think it was them that had almost the same diagrams with all three wheels pointing out the same things. Did everyone get all butt-hurt like this then too?
    Fall in Fruita/GJ. F' yeah! Lunch Loops are riding sweet and so is everything else.

  43. #43
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    Giant's marketing math

    Quote Originally Posted by Saddle Up View Post
    Okay, just a minute let me check my mumbers against Giants, yep they are correct. If only Specialized had the balls to publish stuff like this, I thinks it's pretty awesome for them to share the 'why' they are moving in this direction. I want Specialized to publish the numbers for 'why' they are not onboard.

    Isn't it all marketing, I get this ad on the top of my page for Orbea bikes, it's for an Occam or something, the marketing line is "ride fast on 'any' terrain". I don't know, the bike looks like a 29 xc bike, what does any terrain mean?, any terrain means any terrain doesn't it. I'm not doing a downhill run on it.
    Publishing the 'why nots' would be a bad business move on their part. That would effectively shut the door to the market for them and they don't want that. "But you guys said 650b sucked and now you're selling 650b? Wtf?"
    The leg bone's connected to the Cash Bone!

  44. #44
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    Giant's marketing math

    Quote Originally Posted by 911Holy$ View Post
    hmmm. post #15 by you was a little confusing:

    "The marketing is that it is exactly half way in between. So what's your point?"
    I was responding to post #11 where somebody accused somebody else of falling for marketing for saying 650b is the "in between" wheel size. Of course 650b obviously is in FACT "in between". That is NOT marketing, it is mathematically undeniable truth. The question is where on the scale between 26 and 29 it actually lies. To say it is exactly half way in between is not precisely true (though not wildly inaccurate). So if claiming exactly half way in between is used to sell bikes, it is marketing.

    Clear?
    Old enough to know better. And old enough not to care. Best age to be.

  45. #45
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    Quote Originally Posted by dwt View Post
    Lotta controversy in the forums about this. Seems to have lit a new spark in the "27.5" is all about marketing" line of hate.

    Giant has gone all in as far as production, but have they gone over the line as far as marketing?

    I'm no physicist, engineer or mathematician, so have no ability to analyze it.

    So, whether lover or hater, does anybody have any grounded in fact rebuttal, or for that matter, confirmation?



    Giant Unveils 2014 Mountain Bikes with 27.5 Wheels | Bicycling Magazine
    Giant need to push it hard because I think they are stuffed with any other wheel size. Maestro was designed with 26" wheel in mind. 26" is dead. They had to do all sorts of frame contortions just to squeeze in 120mm travel in a 29er. 29ers are still progressing to shorter chain stays and longer travel. So they are stuffed for future generations in 29ers. Hence the big push in to 27.5. They're not the only ones. But there's nothing wrong with that. Good to have a choice in wheel size.


    I haven't bothered to check their maths but the contact patch size doesn't seem right. On the trail there's still a big difference in cornering traction between a 27.5 and a 29er. Once again mid way feels closer. Definitely not closer to 26" like the size haters would make us believe.

  46. #46
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    Some strange arguments here. First I will say I am a Giant dealer so I have an obvious bias. Second Giant does not claim that 27.5 is halfway between 26 and 29, in fact they claim the exact opposite, that when it comes to performance it is never halfway between the two.

    The math, and therefore the physics is what it is and arguing against it is silly. The thing is wheels have this circle thing going, and there is this fundamental pi*r2 thing going on. Which means things increase and decrease at an exponential rate. As wheels get bigger they get exponentially worse as far as weight, acceleration and stiffness are concerned. As wheels get smaller they get exponentially worse at angle of attack and contact patch. (And don't try and tell me that a 10"x2" wheel has the same contact patch as a 40"x2" wheel, there is a difference in contact patch whether you like it or not.)

    So then the question is, where is the sweet spot where you get the best combination of characteristics. Giant makes a good argument for 27.5 being a better combo than 26 or 29 and backs it with solid math.

    I like the argument that in the end it comes down to how does it feel when you ride it. Unfortunately I didn't get this question answered for me at Giant's dealer show. The first two bikes I rode were completely different bikes than what I normally ride and so didn't make a good comparison. The last one I rode was a good comparison, but unfortunately my wife crashed and so I had to end the ride too soon to really get a feel for the bike.

    The demo Anthem Adv 27.5s I have on order are very close in spec to the Anthem X Adv 29 that I am currently riding. When the demo bikes get here I will get a good chance to take them both out on the same trails and be able to answer for myself if the 27.5 is really the answer Giant says it is.

    When I first started riding the 29er I missed the quick snappy feeling of my 26, but with lighter wheels and time I have learned to love my 29er. Giant claims that with the 27.5 the snap is back. I would be glad to have that back and still have the faster rolling and more traction. In a few weeks I'll be able to see for myself if Giant is right. Also I can demo out my bikes to customers and see if they agree with Giant.

  47. #47
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    Giant's marketing math

    Quote Originally Posted by mtbeagle View Post
    Giant claims that with the 27.5 the snap is back. I would be glad to have that back and still have the faster rolling and more traction.
    It's BACK.

    The Snap is Back.
    - -benja- -

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    Quote Originally Posted by saidrick View Post
    The problem I have with the Giants marketing is that it doesn't make sense:
    They claim that bigger wheel size equals better traction?
    That's a function of tires , not wheels.
    They claim that better roll over gives you better cornering?
    I am not sure how that works, since most corners are not full of rocks and roots.
    I have to respectfully disagree with that statement. I was running Rocket Ron Pace stars on my 26", then I test rode a 29er with Racing Ralphs Performance compound which by all rights should not stick better, but the did. A lot better. And when I test rode the Talon 27.5 with the budget Giant tires I had all the grip I wanted. To me it definitely feels like the bigger wheels offer more grip. But those are my personal observations.

  49. #49
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    WRT contact patch size, remember most people running 29ers use less pressure in the tires than most people running 26ers. So even if we assume that a wider patch would be in contact with the 26" wheel, and a longer patch with the 29" wheel, generating a supposedly equal sized contact patch, remember that with less PSI in the larger wheel/tire, there MUST be MORE tire on the ground to support the equal pressure pushing down on the two tires. This really is simple physics. The bonus here, for the lower PSI tire, is that any surface anomalies (rocks, roots) poking up also displace the tire less because the lower PSI allows the tire to flex more. This is part of what the Tubeless Hype is all about. On the whole, all other things being equal, a larger tire at a lower PSI is ALWAYS going to have a larger contact patch.

  50. #50
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    Quote Originally Posted by mtbeagle View Post
    Some strange arguments here. First I will say I am a Giant dealer so I have an obvious bias. Second Giant does not claim that 27.5 is halfway between 26 and 29, in fact they claim the exact opposite, that when it comes to performance it is never halfway between the two.

    The math, and therefore the physics is what it is and arguing against it is silly. The thing is wheels have this circle thing going, and there is this fundamental pi*r2 thing going on. Which means things increase and decrease at an exponential rate. As wheels get bigger they get exponentially worse as far as weight, acceleration and stiffness are concerned. As wheels get smaller they get exponentially worse at angle of attack and contact patch. (And don't try and tell me that a 10"x2" wheel has the same contact patch as a 40"x2" wheel, there is a difference in contact patch whether you like it or not.)
    Actually things don't all increase at an exponential rate. Only area does for a circle. A 29" circle is just 29/26 larger in diameter than a 26" circle. I fail to see where the area of a spoked wheel is relevant here.

    If you use the same tire and the same rim, a 29" wheel will be about 12% heavier. If you used a tire and rim combo that was 12% lighter on the 29" wheel it would weigh the same and accelerate the same as a 26" wheel. The diameter doesn't matter because the bigger wheel turns proportionally slower, which cancels things out.

    What the diameter DOES do is put the gyroscopic effect and the polar moment of inertia further out. It's like wiggling a short stick and a long stick. In order to turn the wheel X degrees you have to swing the same weight through a longer arc.

    The acceleration effect you only feel when you are accelerating, but the polar inertia effect is there whenever you're turning the wheel side to side or leaning the bike over. That's what I notice far more than any acceleration differences, and given that I can generally use lighter tires on 29 than I did on 26 makes that a wash for me.

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