Rank ‘em – what makes a bike less flexy?- Mtbr.com
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  1. #1
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    Rank ‘em – what makes a bike less flexy?

    In your opinion, what contributes most to a stiffer, better-tracking, more confidence-inspiring ride? Noticed my new-ish 29” HT is noticeably more flexy than my previous 26” FS (still prefer the HT), so I began mulling over all the factors that make one bike stiffer than another.

    Here are my rankings, based on little actual experience but a whole lot of e-riding :

    1. Frame design
    2. 20 mm thru-axle
    3. 15 mm thru-axle
    4. Front-wheel build (rims, spokes, tension, etc)
    5. Tapered head tube AND tapered steerer
    6. Tapered head tube w/ straight steerer

    Would love to read the opinions of more experienced riders. Feel free to remove, add to, or combine items on my list.

  2. #2
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    Wheels. Who cares how stiff any of that other stuff is if you are riding around on noodley wheels. You will feel that first.

  3. #3
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    Quote Originally Posted by Onetrack
    Wheels. Who cares how stiff any of that other stuff is if you are riding around on noodley wheels. You will feel that first.
    this is complete myth.
    relatively speaking, wheels are a tiny contributor to overall flex.
    talk to someone who has gone from 9mm q/r to 20mm thru axle with the same wheel.

    as far as ranking the list, it would take a lot of back-to-back experience on a lot of bikes that I don't have, but thru axles are major. I would put them at the top of the list.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  4. #4
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    1. Through axles.
    2. Hydroformed tubing, be it oval, rectangular, whatever for front and rear triangle on a FS.
    3. Big azzed diameter bearings with plenty of load bearing surface in the Linkage on a F.S. bike.
    4. Forks with enough material in them to thoroughly support the stanchions adequately, while not generating too much stiction.
    5. Over width tires, with low air pressure, on narrow rims without enough material or weigh in the rims, for the job at hand.
    I'm just a Clyde, all the little things add up at my weight.
    Last edited by Boyonabyke; 08-28-2010 at 08:25 PM.

  5. #5
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    A smaller gut?

    Yes, steel is most certainly stronger than aluminum EVERY time.
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  6. #6
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    Quote Originally Posted by FrostyStruthers
    A smaller gut?

    I'm out.
    Guess all bikes I ride will flex.
    Trailwrecker at large

  7. #7
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    Quote Originally Posted by meltingfeather
    this is complete myth.
    relatively speaking, wheels are a tiny contributor to overall flex.
    talk to someone who has gone from 9mm q/r to 20mm thru axle with the same wheel.

    as far as ranking the list, it would take a lot of back-to-back experience on a lot of bikes that I don't have, but thru axles are major. I would put them at the top of the list.

    Frame and fork tubing/construction will trump everything else in my opinion.

    I go back and forth between QR, 20mm, 15mm front TA, and QR, Bolt on, 10mm through bolt, and 12mm maxle on various bikes and have to say that I don't think the way the wheel is attached to the bike makes much if any difference in flex. I am in a minority here, and it's not like I am feather weight either (190 with gear), and I usually notice everything going on in a bike. And yes, I have gone from 9mm QR to 20mm with the same wheel...no difference other than confidence.

    Light weight, noodly rims I can notice in an instant, however. I found Arch rims intolerably flexy while Flows seem to be perfect for me (with similar builds otherwise).

    What the OP is noticing is frame stiffness for sure.
    Quote Originally Posted by buddhak
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  8. #8
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    Agree on the thru axles - I have 3 29ers, all very different rides and have switched all fronts to thru axle - 2 20mm(rigid Ti and converted Fox 36 Talas) and 1 15mm(Fox). I also run either King rear hubs with Fun Bolts(1 SS and 1 Geared) or the 10mm DT Swiss RWS.

    These all have noticably stiffened the bike.
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  9. #9
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    Frame design (more stiffnes in the bottom bracket area I believe, but don't quote me. ...and a few less slices of pizza & hoagie sandwiches!
    roccowt.
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  10. #10
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    Quote Originally Posted by TiRyder
    Agree on the thru axles - I have 3 29ers, all very different rides and have switched all fronts to thru axle - 2 20mm(rigid Ti and converted Fox 36 Talas) and 1 15mm(Fox). I also run either King rear hubs with Fun Bolts(1 SS and 1 Geared) or the 10mm DT Swiss RWS.

    These all have noticably stiffened the bike.
    who built your ti thru axles?
    I like to ride Bikes. This might be turning into an obsession, not sure?

  11. #11
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    I agree with the thru axles as well....However, what good is that if you have super flexy rims and ultra light(revos) spoke build. I believe wheel stifness is a sum of all of the components of a wheel build.

  12. #12
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    I sparked a pretty good debate on wheel stiffness in this thread.

    http://forums.mtbr.com/showthread.php?t=643593

  13. #13
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    I am probably in the minority but I have a standard steerer HT on my Blacksheep and a tapered (with tapered fork steerer) on my Tallboy.
    I feel absolutely no difference between them.
    I have also had standard QR and 9mm bolt through RWS on my front wheel.
    Again I can tell no difference.
    I have test ridden a a Tallboy with a 20mm QR. Again I felt no difference.
    As a result of this I had Fox make me a tapered steerer fork for my Tallboy with a standard dropout rather than having some QR and some 20mm wheels.

    I can feel a badly built wheel though.

  14. #14
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    Quote Originally Posted by Enel
    What the OP is noticing is frame stiffness for sure.
    Could be. I assumed it was the switch from 20mm TA to qr that led to the flexy feel, but I also went from a frame with an almost 6" headtube with an internal hs, to a frame with a 3.5" headtube.

    My "list" is pure conjecture, based loosely on what I've read here on mtbr.

  15. #15
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    These are huge:
    -thick stanchioned fork.
    -good stem/handlebar combo.
    -ta on front wheel.

  16. #16
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    I can vouch for the wheels themselves not mattering much. On my rigid Haro, I went from the OEM wheelset (Pivit hubs, 32 spokes, WTB 28mm rims, quick release) to some burly wheels (DH hubs, 36 spokes, Gordo rims, bolt on front axle) and didn't feel any real change in side to side flex or windup.

    Something that surprised me how much it matters: handlebar / stem / seatpost. The OEM stuff (Mary bar, Ritchey and Pivit) seemed OK. The new stuff (Ragley bar, Thomson) was SO solid and stiff it felt like a new bike. Front and back.

  17. #17
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    Quote Originally Posted by TiRyder
    Agree on the thru axles - I have 3 29ers, all very different rides and have switched all fronts to thru axle - 2 20mm(rigid Ti and converted Fox 36 Talas) and 1 15mm(Fox). I also run either King rear hubs with Fun Bolts(1 SS and 1 Geared) or the 10mm DT Swiss RWS.

    These all have noticably stiffened the bike.
    James at Blacksheep. I have a unicrown 20mm thru on a Quiring SS. He is also in process of building a 15mm Faith Truss fork to be run on a Mooto-X.

    Also - Gotta say that I def can tell difference between wheelsets, not sure why Melting Feather is so adamant that its a myth.
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  18. #18
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    Quote Originally Posted by antonio
    In your opinion, what contributes most to a stiffer, better-tracking, more confidence-inspiring ride? Noticed my new-ish 29” HT is noticeably more flexy than my previous 26” FS (still prefer the HT), so I began mulling over all the factors that make one bike stiffer than another.

    Here are my rankings, based on little actual experience but a whole lot of e-riding :

    1. Frame design
    2. 20 mm thru-axle
    3. 15 mm thru-axle
    4. Front-wheel build (rims, spokes, tension, etc)
    5. Tapered head tube AND tapered steerer
    6. Tapered head tube w/ straight steerer

    Would love to read the opinions of more experienced riders. Feel free to remove, add to, or combine items on my list.
    1. lots of metal/carbon
    2. no suspension
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  19. #19
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    Quote Originally Posted by meltingfeather
    this is complete myth.
    relatively speaking, wheels are a tiny contributor to overall flex.
    talk to someone who has gone from 9mm q/r to 20mm thru axle with the same wheel.

    as far as ranking the list, it would take a lot of back-to-back experience on a lot of bikes that I don't have, but thru axles are major. I would put them at the top of the list.
    Not quite completely a myth. A seat of the shorts comparison with the same rider (me), same hardtail bike, same tires (at the same pressure), same skewers, on the same trail.

    While riding in a narrow (3-5" wide/2-3" deep) parallel rain rut I could feel a wiggle in the rear end of the bike. Checked for loose skewer, cracked frame, loose hub, spokes, soft tire. All OK. Duplicated the feeling on 2-3 rides.

    Swapped wheels, moving the same tires to them. The wiggle was gone, and remained gone on 2-3 rides.

    Returned to wheelset #1 and the wiggle returned.

    Wheelset #1: Bonty Rhythm Comp (28 14/15 DB spokes) QR
    Wheelset #2 Bonty Duster rims on XT hubs (32 14/15 DB) QR
    Both properly tensioned.
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  20. #20
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    Quote Originally Posted by TiRyder
    James at Blacksheep. I have a unicrown 20mm thru on a Quiring SS. He is also in process of building a 15mm Faith Truss fork to be run on a Mooto-X.

    Also - Gotta say that I def can tell difference between wheelsets, not sure why Melting Feather is so adamant that its a myth.
    wheels feel different, there's no arguing that (i never have). to make a specific claim about a specific property of wheels (stiffness) or attribute the difference in feel to one property based on a seat-of-the-pants (trail) impression is a huge stretch. based on what i know about wheels, it's a very hard case to make, on top of being a logical leap of faith. saying that you'll feel a "noodley" wheelset before frame design & thru axle is just silly. i don't know how much you all think wheels flex, but it's not all that much. it doesn't take that much deflection of the rim to makes spokes go slack, and when spokes go slack, wheels go out of true and sometimes taco.
    if it matters, my opinion that wheel stiffness is hugely overplayed is shared by all of the most knowledgeable people on the topic of bike wheels that i've encountered, and i've seen as well as gathered data (measurements) to inform it. read any or all of the books on wheelbuilding... there's a fairly clear consensus. i wonder why that is...
    opinions based on trail impressions are worthless. according to some here, you're wasting your money on thru axle forks and should instead spend your money on straight gauge spokes. still others say that cranking your spoke tension to 140 kgf will solve flexing issues.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  21. #21
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    This should get interesting!

    Meltingfeather and Enel in a knock down drag out fight.

    According to Meltingfeather a very stiff tire with little flex should be the biggest factor of all.

    In fact, I think I am going to soften my suspension and just ride on my rims!
    My brain went from "you probably shouldn't say that" to WTF!

  22. #22
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    Quote Originally Posted by shiggy
    Not quite completely a myth. A seat of the shorts comparison with the same rider (me), same hardtail bike, same tires (at the same pressure), same skewers, on the same trail.

    While riding in a narrow (3-5" wide/2-3" deep) parallel rain rut I could feel a wiggle in the rear end of the bike. Checked for loose skewer, cracked frame, loose hub, spokes, soft tire. All OK. Duplicated the feeling on 2-3 rides.

    Swapped wheels, moving the same tires to them. The wiggle was gone, and remained gone on 2-3 rides.

    Returned to wheelset #1 and the wiggle returned.

    Wheelset #1: Bonty Rhythm Comp (28 14/15 DB spokes) QR
    Wheelset #2 Bonty Duster rims on XT hubs (32 14/15 DB) QR
    Both properly tensioned.
    this is about as good as it gets when it comes to a comparison, and making a case against what someone thought they felt on a trail is impossible. this is precisely the reason why scientists and engineers use the tool of measurement, because it provides a common and standard frame of reference for discussion. some here can't feel a difference in thru axle vs. q/r... others put it at the top of the list... how do you solve that? measurement!
    i wonder what your blind trail impression of a tied-and-soldered vs. conventional wheelset would be, all else equal.
    Last edited by meltingfeather; 08-23-2010 at 08:02 PM.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  23. #23
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    Quote Originally Posted by meltingfeather
    this is about as good as it gets when it comes to a comparison, and making a case against what someone thought they felt on a trail is impossible. this is precisely the reason why scientists and engineers use the tool of measurement, because it provides a common and standard frame of reference for discussion. some here can't feel a difference in thru axle vs. q/r... others put it at the top of the list... how do you solve that? measurement!
    i wonder what your blind trail impression of a tied-and-soldered vs. conventional wheelset would be, all else equal.
    did you get my response re: little alberts, btw?
    So how much stiffer does a 20mm through axel make a bike?
    I know you asked us to ask someone who has gone to one, but isn't that subjective as well? I think we need scientific measurements to quantify this!
    My brain went from "you probably shouldn't say that" to WTF!

  24. #24
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    Quote Originally Posted by richwolf
    So how much stiffer does a 20mm through axel make a bike?
    I know you asked us to ask someone who has gone to one, but isn't that subjective as well? I think we need scientific measurements to quantify this!
    If this data is out there I would love to see it. I agree that accurate measurement trumps subjective impressions, but all I see out there is subjectivity. Where is this data?
    Quote Originally Posted by buddhak
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  25. #25
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    [QUOTE=Enel]If this data is out there I would love to see it. I agree that accurate measurement trumps subjective impressions, but all I see out there is subjectivity. Where is this data?[/QUOTE

    I did a search and found nothing other than subjective data on the through axle thing.

    I am just poking a little fun at Mr Feather cause he spanked me badly in another thread!
    But if he is going to throw stuff out there then he better be able to back it up with some science. What is good for the goose is good for the gander.

    But most of us don't buy bikes on science, we buy them on feel and looks and recommendations from others that probably have little science to back up their decisions.

    When I buy a product, I research it, and if it has a high rating based on customer feedback, then that is usually what I get. It has served me well from phones, to computers, to books. I am sure those people are not out there doing science on those products before they make their decisions.

    Look at the product reviews on this site. I am sure most of them are subjective but I would rather take a chance on a product with a higher review than a lower one.
    My brain went from "you probably shouldn't say that" to WTF!

  26. #26
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    Quote Originally Posted by Enel
    If this data is out there I would love to see it. I agree that accurate measurement trumps subjective impressions, but all I see out there is subjectivity. Where is this data?
    But you just proclaimed that frame & tube construction is paramount & structural connections are irrelevant. If you believe that you can find a hole in any data. After all, all you need to say is that a bench test is irrelevant to trail feel.
    If you don't understand why a thru axle is a far stiffer & stronger structural connection than a quick release, data will probably just confuse you, and since it won't fit with your categorical proclamation, would most likely be disregarded.
    No offense, but the "for sure" claim that completely disregards going from 20mm thru axle to quick release discounts a pretty obvious factor in favor of a black-or-white declaration.
    Last edited by meltingfeather; 08-23-2010 at 08:23 PM.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  27. #27
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    maybe the better question is where do you want a bike to flex and where to you want it to be rock solid?

  28. #28
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    Quote Originally Posted by richwolf
    I did a search and found nothing other than subjective data on the through axle thing.

    I am just poking a little fun at Mr Feather cause he spanked me badly in another thread!
    But if he is going to throw stuff out there then he better be able to back it up with some science. What is good for the goose is good for the gander.
    Fair enough.
    It is easy enough to show, on paper and in a lab, why the connections between fork and wheel in a thru axle set-up are far stronger and stiffer than a quick release. If I wasn't able to easily see the flex in the q/r fork on my rigid ss, I might say it's irrelevant, but that joint is a critical one and q/r vs. thru axle is night/day. Wheel vs. wheel is splitting hairs in comparison, and while I have never argued that the princess and the pea story was untrue, I find it far fetched and unlikely.
    Quote Originally Posted by richwolf
    But most of us don't buy bikes on science, we buy them on feel and looks and recommendations from others that probably have little science to back up their decisions.
    This is true, but somehow in the various realms of discussions about bikes, the worlds get mixed... almost always is it declarations about the science based on feel, rather than the other way around, and often it is misinformed.
    I have never and will never argue that someone shouldn't buy/ride a bike based on how it feels, but if you tell me your wheels are stiffer than homeboy's, I ain't buying it unless I see some numbers.

    Quote Originally Posted by richwolf
    Look at the product reviews on this site. I am sure most of them are subjective but I would rather take a chance on a product with a higher review than a lower one.
    This is true as well, and the reviews on this site are a great resource when considered for what they are. It should always be recognized that one person's opinion can easily be different from another's; this thread is testament to that fact. Should you or shouldn't you buy a thru axle fork if you think the front of your bike is flexy? What's the benefit of that vs. straight gauge spokes? These are questions opinions can't answer.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  29. #29
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    Feather,

    Still looking for the data on QR vs. bolt through?
    My brain went from "you probably shouldn't say that" to WTF!

  30. #30
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    In my experience, swapping from quick release axle with xt skewer to solid axle, in the same wheel on the same bike, made a big difference. My Reba Team with maxle was also a hell of a lot stiffer than my Reba SL with a number of different quick release axles. That's not really applicable though because it's a different fork, and I was using a completely different wheel.

    So, I would agree that type of wheel to fork/frame connection would be #1. Frame and fork construction/design would be #2. Wheel build #3. Smell of bike #4. Color of bike #5.

  31. #31
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    Quote Originally Posted by richwolf
    Feather,

    Still looking for the data on QR vs. bolt through?
    don't know of any. your trying to force the point has gotten across, but you haven't made a point. if it is not plainly obvious that a 20mm thru axle interface is stronger and stiffer than a quick release, maybe i can line it out for you a bit tomorrow. look at some pictures, think about the forces, it is night and day. a pretensioned structure, which has some pretty counter-intuitive behavior, is not quite as obvious. nobody really argues that a thru axle is not stiffer or stronger than a q/r because it is very easy to see and understand. maybe it's for this same reason that manufacturers don't feel a need to publish data.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  32. #32
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    Biggest difference...

    No joke, here's the most prominent factor leading to the very subjective feeling of "flexyness".

    A fat rear tire on a narrow rim.

    That is especially true if the tire has thin sidewalls and the air pressure is on the lower end. And by "fat" and "narrow" I mean even mean a mismatch as slight as a WW LT on an Arch. The rear end will feel squirrely.

    Think about the "tire-rim" design on almost any other vehicle... Rim width and tire width aren't nearly as mismatched as you'd see on mountain bikes. While I do like the "susupension" I get from a fat tire on a rigid bike, I'll take a "narrower" tire on a "normal" width rim any day on a suspension bike. Pay some attention to this particular and you'll notice it. As a side note, I've never been a fan of the whole "overly" fat tire issue on a mtb. Folks are now convinced we all need big fat tires, even on susupension bikes, to negotiate the same trails. This has led to wider chainstays and less front ring clearance and derailure clearance issues. (Enough of the rant.)




    All the other stuff does make a difference but keep this very important concept in mind:

    A chain is only as strong as it's weakest link.

    For example, put King fun bolts on a flexy rear end and most of the resolved "play" that is eliminated from the QR dropout will just be sent on down the line to the flexy chainstays.


    Fat tire on a narrow rim = flexy feel.

  33. #33
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    Quote Originally Posted by meltingfeather
    don't know of any. your trying to force the point has gotten across, but you haven't made a point. if it is not plainly obvious that a 20mm thru axle interface is stronger and stiffer than a quick release, maybe i can line it out for you a bit tomorrow. look at some pictures, think about the forces, it is night and day. a pretensioned structure, which has some pretty counter-intuitive behavior, is not quite as obvious. nobody really argues that a thru axle is not stiffer or stronger than a q/r because it is very easy to see and understand. maybe it's for this same reason that manufacturers don't feel a need to publish data.
    I am just asking how much different the flex is between a QR and a through axle (given the same fork brand and wheel)? Is it 1mm, 5mm 10mm?
    Is it greater than the difference between a rigid fork and a suspension fork?
    Without measurements and science how can we really know?
    My brain went from "you probably shouldn't say that" to WTF!

  34. #34
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    I've had flexing issues on all of my bikes. However, Lynskey built me a custom frame with a larger TT, larger chain stays and a wider BB shell. It's way stiffer than my previous frames and tracks likes it's on rails. I also run Stans Flows, with DT Swiss 9mm and 10mm axles/quick releases. The wheels make a huge difference as well. Broke a spoke recently on my Stans wheels and had the misfortune of putting my old Bontrager Rhythm's back into service. Rode those on one ride and the familiar wheel rub came back as well as more squirrely handling.

  35. #35
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    Quote Originally Posted by meltingfeather
    If you don't understand why a thru axle is a far stiffer & stronger structural connection than a quick release, data will probably just confuse you, and since it won't fit with your categorical proclamation, would most likely be disregarded.
    I see that there is a difference, and I know why. I just think this area of flex is much less significant than the many other areas flex introduced by long lever arms on the fork, frame, etc. Both methods of connecting the wheel to the drop outs are extremely secure and I think the differences between them have to be miniscule compared to all the other sources of flex on a bike.

    Here is a less than scientific demonstration:

    I ride a Lenz frame (by all accounts pretty stiff in the head tube) with a 20mm Maxle 120 Reba and Flow 29" wheels

    My buddy rides a Bionicon: 26" wheels, dual crown fork, 150mm travel and a QR wheel attachment.

    Anyone with any sensitivity can tell his front end is worlds stiffer despite the QR. The dual crown design and smaller wheels, and possibly frame trump the axle interface.

    The other question is how much flex is required before an an observer subjectively notices it?

    The OP's question had to to with what are the main contributors which IMO are still:

    1. Frame construction
    2. Fork construction
    3. Wheel construction
    4. Axle interface.

    The weakest link in the above will be the most noticeable in any particular situation though.
    Quote Originally Posted by buddhak
    And I thought I had a bike obsession. You are at once tragic and awesome.

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    Quote Originally Posted by richwolf
    I am just asking how much different the flex is between a QR and a through axle (given the same fork brand and wheel)? Is it 1mm, 5mm 10mm?
    Is it greater than the difference between a rigid fork and a suspension fork?
    Without measurements and science how can we really know?
    Flex depends on the load. Stiffness is given in units of force per deflection (e.g., N/mm).
    Where you want the measurements taken, what kind of stiffness (lateral, torsional, axial, etc.), and what is to be controlled for is at the discretion of the designer of the study and what they want to know.
    What you mean by "the difference between a rigid fork and a suspension fork" is a good question. The difference being the fact that a suspension fork can compress, sometimes up to 9"?
    Sometimes things that are obvious enough don't need to be detailed out. You wouldn't hang off the side of a cliff from a piece of thread, but a 60mm climbing rope? No problem. Do you need a measurement to tell you that's OK? I am drawing a distinction between things that are obvious and things that are more subtle. Because it is so obvious that thru axles are stronger and stiffer than quick releases, studies comparing the two are kind of a waste of time. Basically, if there is enough disagreement about something and no clear resolution, people measure to find out the answer... like with spoke tension & stiffnes, for instance. MANY people erroneously think that spoke tension affects wheel stiffness. It does not. A few measurements put that to rest without question, but there are still people who dispute it based on leaning on a wheel on their kitchen floor or some other seat-of-the-pants estimation. Heck, maybe even based on trail feel, because I have done the experiement and I can tell you that the same wheel at significantly different tension feels different. It's not stiffness, but it still feels different.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  37. #37
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    Quote Originally Posted by meltingfeather
    Flex depends on the load. Stiffness is given in units of force per deflection (e.g., N/mm).
    Where you want the measurements taken, what kind of stiffness (lateral, torsional, axial, etc.), and what is to be controlled for is at the discretion of the designer of the study and what they want to know.
    What you mean by "the difference between a rigid fork and a suspension fork" is a good question. The difference being the fact that a suspension fork can compress, sometimes up to 9"?
    Sometimes things that are obvious enough don't need to be detailed out. You wouldn't hang off the side of a cliff from a piece of thread, but a 60mm climbing rope? No problem. Do you need a measurement to tell you that's OK? I am drawing a distinction between things that are obvious and things that are more subtle. Because it is so obvious that thru axles are stronger and stiffer than quick releases, studies comparing the two are kind of a waste of time. Basically, if there is enough disagreement about something and no clear resolution, people measure to find out the answer... like with spoke tension & stiffnes, for instance. MANY people erroneously think that spoke tension affects wheel stiffness. It does not. A few measurements put that to rest without question, but there are still people who dispute it based on leaning on a wheel on their kitchen floor or some other seat-of-the-pants estimation. Heck, maybe even based on trail feel, because I have done the experiement and I can tell you that the same wheel at significantly different tension feels different. It's not stiffness, but it still feels different.

    How about deflection at the outer part of the rim vis a vis the fork blades?
    But for studies to be called by you a "waste of time" begs your signature line don't they?
    My brain went from "you probably shouldn't say that" to WTF!

  38. #38
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    Well if you based what you "need" off of 1/2 of mtbr forums everyone would have a 20mm T/A tapered fork, a set of 203mm rotors , a 12mm T/A rear axle with 150mm spacing, aluminum bars (after all carbon could break..), and a hand built in " " (you choose it) frame with super hydoformulated ultragussetinforced quadhelixtified spacegalaxyepic tubing...etc...etc... etc...- or you don't have $h!t- The whole thing really just needs to match the application-

    I think the one thing that sums it all up is that the whole deal is only as strong as the weakest link ...so changing one thing may not have a whole lot of influence but when combined the end result is noticeable. If the frame, fork and hub interface is stiff you are more likely to notice if the wheels are flexy or a tire has a sqirmy sidewall.

    I have qr, 15mm, 20mm forks and have run qr with 9mm RWS... in most of my XC/trail riding it is not a huge factor. If I ride both back to back with very few other variables I may notice.... but by this point I've already adapted to whatever I am on... so I can't really say if I would have been able to thread the front wheel between those two rocks with my 15mm axle or needed to run over one if I had my qr fork! thus why most of us can hop off of a full rigid SS on to a 27 (or 30!) speed full suspension bike and actually ride the same trails on either and make it back to the trailhead to talk about it.

    I am ranting so not even sure where this is going any more... subject to editing
    I Just wish I could ride more!


  39. #39
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    Quote Originally Posted by Enel
    I see that there is a difference, and I know why. I just think this area of flex is much less significant than the many other areas flex introduced by long lever arms on the fork, frame, etc.
    Fair enough, this is a subjective judgement that we just disagree on (see my qualifications below about your extreme example). Nothing wrong with that.
    Quote Originally Posted by Enel
    Both methods of connecting the wheel to the drop outs are extremely secure and I think the differences between them have to be miniscule compared to all the other sources of flex on a bike.
    I have never heard of a disc-braked bike with a thru axle loosening or ejecting a wheel like has happened (and even been litigated) with quick releases + disc brakes. I wouldn't put a friction interface in shear anywhere near the secureness of a solid mechanical connection; to do so is kind of ridiculous. Also, I was mostly talking about stiffness, not security, but the answer is the same.
    Quote Originally Posted by Enel
    Here is a less than scientific demonstration:

    I ride a Lenz frame (by all accounts pretty stiff in the head tube) with a 20mm Maxle 120 Reba and Flow 29" wheels

    My buddy rides a Bionicon: 26" wheels, dual crown fork, 150mm travel and a QR wheel attachment.

    Anyone with any sensitivity can tell his front end is worlds stiffer despite the QR. The dual crown design and smaller wheels, and possibly frame trump the axle interface.
    An extreme example can stretch a point, for sure. What I said was in reference to equipment designed for like purposes, not comparing what is known to be a flexy XC 29er fork with a Maxle to a dual crown 6" travel 26" fork with a quick release. I also wasn't working off of your ammended list that includes fork construction. I guess I didn't anticipate this comparison including downhill equipment vs XC, in which case fork and frame construction play a larger role in the difference, obviously. why not include ski bikes?
    Quote Originally Posted by Enel
    The other question is how much flex is required before an an observer subjectively notices it?
    This question has no answer, so I'd say it is irrelevant, and that's why I pointed out that opinions are useless. What feels boner stiff to one guy might feel like a noodle to another. You can trade opinions about it all day and not get anywhere.
    Quote Originally Posted by Enel
    The OP's question had to to with what are the main contributors which IMO are still:

    1. Frame construction
    2. Fork construction
    3. Wheel construction
    4. Axle interface.

    The weakest link in the above will be the most noticeable in any particular situation though.
    No matter the scope, axle interface over wheel construction all day (just to be clear I'm not including Aerospoke wheels, TT disc wheels, motorcycle wheels, or anything other than equipment designed for similar purposes).

    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  40. #40
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    Quote Originally Posted by richwolf
    How about deflection at the outer part of the rim vis a vis the fork blades?
    But for studies to be called by you a "waste of time" begs your signature line don't they?
    Deflection at the outer part of the rim relative to the fork blades would be wheel stiffness, but thanks for the idea.
    I get it... you're forcing the point about me & measurements, it's cute, but I get it. If you're trying to start a flame war, you're not going to. If I thought you were seriously trying to answer the question and not just being antagonistic, I might offer some help.
    What I'm talking about is the difference between splitting hairs and having some common sense. I qualified my statement pretty thoroughly.
    Re: the statement about my signature, thanks for trying to enforce some kind of morality, but thru axles are not 'hype,' and science is not a religion that needs to be relied on for everything. What measurement do you use to get your @ss wiped right?
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  41. #41
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    Quote Originally Posted by meltingfeather
    Deflection at the outer part of the rim relative to the fork blades would be wheel stiffness, but thanks for the idea.
    I get it... you're forcing the point about me & measurements, it's cute, but I get it. If you're trying to start a flame war, you're not going to.
    What I'm talking about is the difference between splitting hairs and having some common sense. I qualified my statement pretty thoroughly.
    Re: the statement about my signature, thanks for trying to enforce some kind of morality, but thru axles are not 'hype,' and science is not a religion that needs to be relied on for everything. What measurement do you use to get your @ss wiped right?

    My we are getting testy are we not? I am glad you are the moderator as to when science is needed and when it is not.
    Where else are you going to measure the stiffness? It all comes down to where the rubber meets the trail. Sure there will be some wheel flex measured but shouldn't it be less with a through axle vs. a QR?

    Regarding wiping, I usually wait till I get in the shower! Saves paper you know.
    My brain went from "you probably shouldn't say that" to WTF!

  42. #42
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    Quote Originally Posted by richwolf
    My we are getting testy are we not?
    Nah... joking, dood. You're the one trying to get a rise out of me.
    Quote Originally Posted by richwolf
    I am glad you are the moderator as to when science is needed and when it is not.
    I'm not. In general science is used to answer questions when seat-of-the-pants estimations are not satisfactory. Anyone can use it whenever they want to. Nobody needs to ask me. All I'm saying is that it's obvious enough that a thru axle is stronger and stiffer than a quick release that manufacturers don't see a need to do comparative studies. I agree with them. If you need the question answered in a precise or scientific way, it looks like you'll have to do it for yourself, as most people seem to understand the difference well enough for themselves.
    Quote Originally Posted by richwolf
    Where else are you going to measure the stiffness? It all comes down to where the rubber meets the trail. Sure there will be some wheel flex measured but shouldn't it be less with a through axle vs. a QR?
    Well, if you're trying to measure fork stiffness, you'd need to measure between two points on the fork. The type of axle does not affect the wheel's stiffness unless the hub is significantly different in design.
    Quote Originally Posted by richwolf
    Regarding wiping, I usually wait till I get in the shower! Saves paper you know.
    tmi, dood.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  43. #43
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    Quote Originally Posted by meltingfeather
    Nah... joking, dood. You're the one trying to get a rise out of me.

    I'm not. In general science is used to answer questions when seat-of-the-pants estimations are not satisfactory. Anyone can use it whenever they want to. Nobody needs to ask me. All I'm saying is that it's obvious enough that a thru axle is stronger and stiffer than a quick release that manufacturers don't see a need to do comparative studies. I agree with them. If you need the question answered in a precise or scientific way, it looks like you'll have to do it for yourself, as most people seem to understand the difference well enough for themselves.

    Well, if you're trying to measure fork stiffness, you'd need to measure between two points on the fork. The type of axle does not affect the wheel's stiffness unless the hub is significantly different in design.

    tmi, dood.
    Not to beat a dead horse but if the axle interface is stiffer as you claim, would it not lead to whole wheel structure deflecting less? Isn't part of this whole discussion of being flexy come down to how it affects the way the bike tracks at the point of contact with the trail? Wouldn't a flexier axle interface contribute to more flex at the rim?
    And as far as QR and lawyers are concerned, sure some wheels have fallen off bikes, but generally it is operator error. Thus the evolution of" lawyer tabs" present on most bikes today. QR's have been in use for a long time and generally this "friction" interface has had a good track record.
    Being a lighter smaller rider and more XC oriented, I don't think the hassles of a through axle make it worth it for me.
    My brain went from "you probably shouldn't say that" to WTF!

  44. #44
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    Quote Originally Posted by richwolf
    Not to beat a dead horse but if the axle interface is stiffer as you claim, would it not lead to whole wheel structure deflecting less? Isn't part of this whole discussion of being flexy come down to how it affects the way the bike tracks at the point of contact with the trail?
    I think this is a semantic issue. Being an engineer, I adhere to pretty strict definitions of things so as to ensure accurate communication about technical issues with other engineers. I guess it's something that has become kind of built in: when I talk about stiffness to another engineer, we have both had what stiffness means beaten into our heads, so we're both talking about the same thing. I can sometimes forget to turn that off or account for the fact that other people don't necessarily interpret stiffness the same way. When you get to more holistic interpretations of stiffness, including "tracking" and other either colloquially defined or undefined terms, things can get fuzzy quick. I can tell you that bridge designers don't use fuzzy terms to communicate about the strucutral elements of a bridge, and for good reason. A good engineer has the ability to bridge that gap for communication, but often times these forum discussions get to a technical level that requires some standard definitions, which is why I worked to develop the draft glossary that I posted here. Unfortunately, not many people seem to be interested. In general, technical discussion tend to glaze people's eyes over.
    When I'm talking about stiffness of a component, I'm talking about applying a load to that component and measuring the deflection of it between two defined points, so when I say fork stiffness, I'm talking about the fork alone. A thru axle adds a very strong and stiff structural connection between the fork ends that significantly changes the fork stiffness, particularly torsional stiffness (the resistance of the fork to twisting along the axis of the steerer), which affects "tracking." It also changes the overall stiffness of any system that includes the fork, one example of which would be the fork/wheel system.
    Quote Originally Posted by richwolf
    Wouldn't a flexier axle interface contribute to more flex at the rim?
    It depends on the two points between which you are measuring the deflection (flex). Almost always stiffness is measured between structural connections and/or applied loads, because that's relevant to structural analysis. A thru axle does not change stiffness between the axle and the ground, which is dictated by wheel and tire stiffness. Wheel stiffness is measured between two points on the wheel (almost always the axle and the rim edge). Tire stiffness is a widely varying spectrum, so it is usually left out, since results that include it can't be generally applied. Measuring and talking about individual components eliminates the variability introduced by different system designs. A wheel manufacturer can not practically describe stiffness of their wheels as a part of whole-bike systems due to the huge number of variables.
    Quote Originally Posted by richwolf
    And as far as QR and lawyers are concerned, sure some wheels have fallen off bikes, but generally it is operator error. Thus the evolution of" lawyer tabs" present on most bikes today. QR's have been in use for a long time and generally this "friction" interface has had a good track record.
    I have a long history of proper use of quick releases and I can tell you that I sometimes have found quick releases loosened after riding, sometimes alarmingly so. The forces that a disc brake imparts on the axle are very large and depending on the geometry of the caliper mount and dropout, can be in the direction of the open end of the dropout, which has no solid structural support for the axle. The resulting micro movements of the quick release have been proven to have the ability to loosen the skewer. It's a problem for some, for others a non-issue, but it is inherent in the design of most disc brake systems, particularly the caliper mount and dropout geometry.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  45. #45
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    Through axles help a whole lot even on some flexible frames. They stiffen it up in just the right way. Even a bolt-on skewer is a noticeable improvement over QR.

    Then its the fork. I think Magura has some of the stiffest ones around, pound for pound.

    Then the bottom bracket area stiffness, including cranks.

    Then the rear suspension.

    Then the wheels. Not sure how to compare - when wheels are strong enough ,they feel roughly the same to me.

    Then suspension tuning. When it is dialed, it just feels the bike tracks better. And it does.

    On the other hand - unless you can not hold a line - who cares about stiffness. It is overrated. I rank talks about stiffness right up there with "flickability", "brake jack" and other perceived issues that occupy minds of spoiled man-children around here.

  46. #46
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    Quote Originally Posted by meltingfeather
    this is complete myth.
    relatively speaking, wheels are a tiny contributor to overall flex.
    talk to someone who has gone from 9mm q/r to 20mm thru axle with the same wheel.

    as far as ranking the list, it would take a lot of back-to-back experience on a lot of bikes that I don't have, but thru axles are major. I would put them at the top of the list.
    I would agree wholeheartedly. I just made the switch from a QR Fox F29 to a Maxle Reba and also switched from 9mm in the back to a Hope 10mm with DT Swiss RWS. The frame is a Ventana El Padrino. I am in Colorado Springs and we have some areas with a lot of rocks and I noticed a big difference in stiffness when riding through the rough stuff with the 20mm thru axle up front and the 10mm in the rear.

  47. #47
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    There's been a lot of typing dedicated to quantifying the nuances of bike feel on this thread, but in other industries that's exactly what many technical people are hired to do. If you want a speaker system to sound a certain way in a particular room, or if you want your mouse button to click a certain way (or not), or even the paper of a book that you're reading to show a certain type of printing in a certain way, you can bet that a gang of engineers figured out what quantity they needed to measure, designed a device to measure it, set up a battery of tests, individually incremented each test variable through its full range, then statistically analyzed the data in a 1000 ways.

    The average Joe's head would explode if he was exposed to even 0.000172% of that data. So that is why some data is not easy to come by.


    For other posters who mentioned "the weakest link" comparison, that makes a lot of sense. You strengthen one area, and the deflection moves. I think some people tolerate (or even prefer) that deflection in certain areas, would be more likely to notice it in others, or would simply ignore it in others. Which may also have to do with riding style and/or terrain. So good luck putting a number on that.

    -F

    PS - rim flex is annoying - when your spokes get loose, or the nipples seat into the eyelet (or whatever happens), it is noticeable. As far as one solid wheel to another, can't say I'd notice anything.

  48. #48
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    Quote Originally Posted by Fleas
    There's been a lot of typing dedicated to quantifying the nuances of bike feel on this thread, but in other industries that's exactly what many technical people are hired to do. If you want a speaker system to sound a certain way in a particular room,
    Bad example. Audiophile tuning is some of the biggest bunch of voodoo around. "Flickability" and "stiffness" seat-of-the-pants testing is some NASA approved methodology in comparison.

  49. #49
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    I know meltingfeather used a quick release friction connection as an example of an inferior connection, but consider just about every stem made uses a friction connection to the steerer tube. Isn't that just wrong?
    I think we need screw on or bolt through stems. I think I am going to drill through my stem tomorrow and add a bolt. I don't think I can sleep at night with the present connection being the way it is!
    My brain went from "you probably shouldn't say that" to WTF!

  50. #50
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    Quote Originally Posted by richwolf
    I know meltingfeather used a quick release friction connection as an example of an inferior connection, but consider just about every stem made uses a friction connection to the steerer tube. Isn't that just wrong?
    I think we need screw on or bolt through stems. I think I am going to drill through my stem tomorrow and add a bolt. I don't think I can sleep at night with the present connection being the way it is!
    I know you've got a personal vendetta going and that's great & everything, but you shouldn't turn your brain off. Friction is involved in every mechanical connection, but that doesn't make it the primary restraint. If you think about it for 5 seconds, and this is kind of funny given your attempt at an argument, a stem/steerer connection is exactly like a fork/thru axle, and fundamentally different from a quick release. For it to be like a quick release the stem would not clamp to the steerer on its own but would need to be open on one side and the top cap bolt would be the primary binder, except it would be a quick release threaded into the star nut. I wonder why they don't do that...
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  51. #51
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    Quote Originally Posted by richwolf
    I know meltingfeather used a quick release friction connection as an example of an inferior connection, but consider just about every stem made uses a friction connection to the steerer tube. Isn't that just wrong?
    I think we need screw on or bolt through stems. I think I am going to drill through my stem tomorrow and add a bolt. I don't think I can sleep at night with the present connection being the way it is!
    Think a little bit about the direction of forces, area of interference fit - and consequences of slippage.

    Those two connections are nothing alike.

  52. #52
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    Quote Originally Posted by Curmy
    Think a little bit about the direction of forces, area of interference fit - and consequences of slippage.

    Those two connections are nothing alike.
    Consequences of slippage? Try riding around with a stem that twists!
    And come to think about it, a handlebar to stem interface is friction too!

    For tonight's ride, since I didn't have time to drill out my stem and handlebar and install a bolt, I just used some self tapping screws
    My brain went from "you probably shouldn't say that" to WTF!

  53. #53
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    Quote Originally Posted by richwolf
    Consequences of slippage? Try riding around with a stem that twists!
    And come to think about it, a handlebar to stem interface is friction too!

    For tonight's ride, since I didn't have time to drill out my stem and handlebar and install a bolt, I just used some self tapping screws
    Like I said in the post that you appear to have missed, friction is involved in every mechanical connection.
    You're really going out on a limb to force a point that I'm sure you could see is nonsensical if you would stop to think about it for a few seconds.
    This is all because you think I "spanked" you in some other thread? Get over it.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
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  54. #54
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    A significant contributor to "flexiness" is the head tube/fork combination. I have two 29ers. The first is a 2005 Fisher Paragon with a 100mm Reba QR and Bontrager Race wheels. The second is a 2008 RIP9 with a 120mm Manitou Minute 29 QR and Stan's Flow/DT 240s wheels. Both have straight 1.125" steerer tubes.
    The Fisher is noticeably stiffer in slow, technical turns. Its head tube is substantially shorter than that of the RIP9 but it has a big gusset that fills in the gap between top tube and down tube. On the RIP9, with the bars turned on a slow, rocky descent, I can feel the front end flex forward and then spring back making the bike less accurate to steer and more difficult to control.
    I used to have Stan's Arch rims on my DT 240s hubs before I rebuilt them with Stan's Flow rims. The more robust wheels made no difference in "flexiness" on the RIP9.
    '99 Safari

  55. #55
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    Quote Originally Posted by meltingfeather
    Like I said in the post that you appear to have missed, friction is involved in every mechanical connection.
    You're really going out on a limb to force a point that I'm sure you could see is nonsensical if you would stop to think about it for a few seconds.
    This is all because you think I "spanked" you in some other thread? Get over it.
    Facetious (that is why I included emoticons)

    bantering: cleverly amusing in tone; "a bantering tone"; "facetious remarks"; "tongue-in-cheek advice"

    Humour or humor (see spelling differences) is the tendency of particular cognitive experiences to provoke laughter and provide amusement. ...

    Not meant to be taken seriously or literally; amusing or humorous

    I guess engineers take themselves too seriously, but for the sake of discussion here is a quote from you:
    "this is about as good as it gets when it comes to a comparison, and making a case against what someone thought they felt on a trail is impossible. this is precisely the reason why scientists and engineers use the tool of measurement, because it provides a common and standard frame of reference for discussion. some here can't feel a difference in thru axle vs. q/r... others put it at the top of the list... how do you solve that? measurement!
    i wonder what your blind trail impression of a tied-and-soldered vs. conventional wheelset would be, all else equal."


    But when I asked for measurement details on a thru axle, you blew it off. Is that what good engineers do?
    My brain went from "you probably shouldn't say that" to WTF!

  56. #56
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    Quote Originally Posted by richwolf
    Facetious (that is why I included emoticons)

    bantering: cleverly amusing in tone; "a bantering tone"; "facetious remarks"; "tongue-in-cheek advice"

    Humour or humor (see spelling differences) is the tendency of particular cognitive experiences to provoke laughter and provide amusement. ...

    Not meant to be taken seriously or literally; amusing or humorous
    Your alternating between antagonism and valid discussion is hard to follow, and I've only found a couple of things that you've said mildly amusing. Honestly I couldn't tell that your whole post about the stem/steerer connection was facetious, especially since you tried to "back it up" after Curmy pointed out that it was silly.
    Quote Originally Posted by richwolf
    I guess engineers take themselves too seriously,
    Not at all. It's just difficult to tell where you're coming from and saying the same thing over and over again, which is an accusation that I'm being hypocritical, is not clever, amusing, or humorous.
    Quote Originally Posted by richwolf
    but for the sake of discussion here is a quote from you:
    "this is about as good as it gets when it comes to a comparison, and making a case against what someone thought they felt on a trail is impossible. this is precisely the reason why scientists and engineers use the tool of measurement, because it provides a common and standard frame of reference for discussion. some here can't feel a difference in thru axle vs. q/r... others put it at the top of the list... how do you solve that? measurement!
    i wonder what your blind trail impression of a tied-and-soldered vs. conventional wheelset would be, all else equal."


    But when I asked for measurement details on a thru axle, you blew it off. Is that what good engineers do?
    I get what you are incenssantly trying to hammer home, and I've addressed it repeatedly. If you hadn't gone about the whole thing by trying to antagonize me with snarky comments, I might have offered some help. Hell, I did offer quite a bit of explanation, but if what you're after is to continue needling me because you think you've caught me in some sort of hipocricy, real dialogue about bicycles won't satisfy you.
    If you can't get over your case of red @ss about something that I said in another thread, I'll just put you on my ignore list and we'll be done.
    This quote doesn't conflict with anything I've said or make your point. If you really can't tell a difference between q/r and thru axle or feel a need to put some precision to the difference, you need to go measure. Most everyone else (including me) seems to be able to so there is no need. I don't feel a need to "solve" the stiffness of q/r vs. thru axle issue because I don't think there's an interesting question there. If you've got a question about it, you'll have to answer it for youself, just like you would if you didn't believe that the world was round. Get it yet?
    I am an engineer, but that doesn't mean I don't use common sense or can't offer an estimation or opinion.
    Last edited by meltingfeather; 08-27-2010 at 09:39 AM.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  57. #57
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    Quote Originally Posted by richwolf
    Consequences of slippage? Try riding around with a stem that twists!
    And come to think about it, a handlebar to stem interface is friction too!

    For tonight's ride, since I didn't have time to drill out my stem and handlebar and install a bolt, I just used some self tapping screws
    You have presented a complete lack of grasp on some very basic engineering concepts. The rest is just incoherent rambling. What is the purpose of you argument? Are you trying to dispute the issues with QR interface used in MTB applications?

    If you where trying to make a joke - I did not get it. I guess sarcasm is lost on teh interwebz.

  58. #58
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    Quote Originally Posted by Curmy
    What is the purpose of you argument?
    Antagonism, I think.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  59. #59
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    Quote Originally Posted by meltingfeather
    Antagonism, I think.

    I explained it, but some engineers don't seem to have a sense of humor.
    You guys seems to take things too seriously. You ask people to prove their points instead of giving subjective opinion, yet when it is turned around, you get all huffy.

    These boards rarely ever get at the truth anyways.

    If you don't like my questions or posts you don't have to respond to them.

    Lot's of friction interfaces work great and I think QR's are one of them. Poor design or operator error can make them fail but I think overall their track record is rather impressive.

    BTW what makes a bike less flexy?
    My brain went from "you probably shouldn't say that" to WTF!

  60. #60
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    Quote Originally Posted by richwolf
    I explained it, but some engineers don't seem to have a sense of humor.
    You guys seems to take things too seriously. You ask people to prove their points instead of giving subjective opinion, yet when it is turned around, you get all huffy.
    Personal attacks via stereotypes aren't productive and don't really come across as humor. I haven't waffled between logic and ridiulosness like you have.
    I've explained myself throughly. If you think my opinion that thru axles are stiffer and stronger than q/r's is wrong the burden of proof is on you, just like if I tell someone that tension doesn't affect wheel stiffness, I provide reasoning and/or data to support the contention. I happen to have a basis for the well qualified opinion I expressed, not that I need one, and despite your poking, explained myself.
    If you are clearly and repeatedly being antagonistic, nobody buys is when you say, "I was joking, lighten up."
    Quote Originally Posted by richwolf
    Lot's of friction interfaces work great and I think QR's are one of them. Poor design or operator error can make them fail but I think overall their track record is rather impressive.
    Nobody disputed that.
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  61. #61
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    Quote Originally Posted by meltingfeather
    You wouldn't hang off the side of a cliff from a piece of thread, but a 60mm climbing rope? No problem.
    Ack! Who the hell carries a 60mm climbing rope? Climbing ropes are typically 9-11mm in diameter. Maybe a 60mm rope is the kind of thing they'd hang in a school gym..for, erm, climbing on. That's got nothing to do with cliffs though.

    Completely off-topic but I'm just saying...

    ___
    "If all your friends were named Cliff you wouldn't jump off them would you?"

  62. #62
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    Quote Originally Posted by Clones123
    Ack! Who the hell carries a 60mm climbing rope? Climbing ropes are typically 9-11mm in diameter. Maybe a 60mm rope is the kind of thing they'd hang in a school gym..for, erm, climbing on. That's got nothing to do with cliffs though.

    Completely off-topic but I'm just saying...

    ___
    "If all your friends were named Cliff you wouldn't jump off them would you?"
    yup. thx for the catch. if i had thought about that for even a second i would have caught it. i mixed length with diameter units. it's kinda funny that i'd miss that, cuz i'm a rock climber (which is why i came up with the analogy in the first place). it happens...
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  63. #63
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    Quote Originally Posted by antonio
    In your opinion, what contributes most to a stiffer, better-tracking, more confidence-inspiring ride? ...so I began mulling over all the factors that make one bike stiffer than another...

    Hi there -

    I hope you guys don't mind our weighing in on this discussion. As most of you know, we recently redesigned our Jet 9, which is an XC FS 29er. While undertaking this task, we conducted a lot of testing and made changes to our designs based on those results - our primary goals being strength, stiffness for power transfer and handling precision and insignificant weight gain. In the linked document, there are a ton of clear comparison pictures - old Jet 9 vs. new Jet 9 - that clearly illustrate the above priorities.

    We are all traveling for Eurobike this week, but I will try to get Steve, who was in charge of this project, to weigh in. I know that he encountered several really interesting numbers and would be a good source of real-world physical testing info that doesn't just apply to our bicycles.

    Anyway, yes, this is a marketing document, but in the context of this conversation, it may make for interesting viewing. I have posted 2 of the many images below as well.

    https://www.box.net/shared/static/nxa1fkt81b.pdf

    Cheers,
    Carla
    Attached Thumbnails Attached Thumbnails -jet9_compare_underside_sm.jpg  

    -jet9_compare_headtubesside_s.jpg  

    .........

    Peace,
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  64. #64
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    Here is the latest in super stiff frame design, one-upping even the helix- combine this state of the art frame design with a BB30, tapered headtube (or a lefty) and obviously T/A's on the hubs (possibly the stem once the conclusive ride reports are back) and wow it will be one serously stiff bike!
    Attached Images Attached Images  
    I Just wish I could ride more!


  65. #65
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    lots of points to ponder in this thread

    tire pressure I didnt seem mentioned simple yes but tire pressure will affect how responsive or the how "tight" a chassis feels to the rider
    to a deeper extent tire construction also plays a factor...


    o2

  66. #66
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    Boy, there sure are a whole lot of personal opinions (aka e-riding masturbation) stated as scientific facts in this thread.

    Show the numbers or go ride, but don't belittle others' opinions as being nonsense when they originate from the same place as yours; conjecture.

  67. #67
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    Is flex bad?

    Okay, flex in some directions is bad, in some its good.

    Worth thinking about....

  68. #68
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    Thoughts on performance of a T/A suspension Fork vs a qr Fork.... for discussion sake-

    I might be imagining it but I have run a few suspension forks with both qr and t/a and always had the feeling that the t/a operated more consistent... smoother etc... could it be that "unifying" the spring and damping side of a conventional fork with a T/A might keep it from "racking" for lack of a better word and possibly binding a bit on the bushings- allowing it to function as intended both "sides" working in unison? It seems to make sense in my head anyway-
    I Just wish I could ride more!


  69. #69
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    Quote Originally Posted by Niner Bikes
    Hi there -

    I hope you guys don't mind our weighing in on this discussion. As most of you know, we recently redesigned our Jet 9, which is an XC FS 29er. While undertaking this task, we conducted a lot of testing and made changes to our designs based on those results - our primary goals being strength, stiffness for power transfer and handling precision and insignificant weight gain. In the linked document, there are a ton of clear comparison pictures - old Jet 9 vs. new Jet 9 - that clearly illustrate the above priorities.

    We are all traveling for Eurobike this week, but I will try to get Steve, who was in charge of this project, to weigh in. I know that he encountered several really interesting numbers and would be a good source of real-world physical testing info that doesn't just apply to our bicycles.

    Anyway, yes, this is a marketing document, but in the context of this conversation, it may make for interesting viewing. I have posted 2 of the many images below as well.

    https://www.box.net/shared/static/nxa1fkt81b.pdf

    Cheers,
    Carla
    Carla,
    Thanks for weighing in! I for one would be interested in more detail about the tests. A picture or description of the testing rig (to illustrate where loads are applied and measurements taken) and some data (loads & deflections) would be killer, but I know that's a lot to ask. I recognize that a marketing brochure doesn't have a need or space for that kind of detail, and it would glaze most people's eyes over if it were in there, but the comparative pictures are great!
    Thanks again!
    Quote Originally Posted by pvd
    Time to stop believing the hype and start doing some science.
    29er Tire Weight Database

  70. #70
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    Quote Originally Posted by Niner Bikes
    Hi there -

    I hope you guys don't mind our weighing in on this discussion. As most of you know, we recently redesigned our Jet 9, which is an XC FS 29er. While undertaking this task, we conducted a lot of testing and made changes to our designs based on those results - our primary goals being strength, stiffness for power transfer and handling precision and insignificant weight gain. In the linked document, there are a ton of clear comparison pictures - old Jet 9 vs. new Jet 9 - that clearly illustrate the above priorities.
    Are you planning to switch to 142x12?

  71. #71
    Carbon & Ti rule
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    Quote Originally Posted by knottshore
    Thoughts on performance of a T/A suspension Fork vs a qr Fork.... for discussion sake-

    I might be imagining it but I have run a few suspension forks with both qr and t/a and always had the feeling that the t/a operated more consistent... smoother etc... could it be that "unifying" the spring and damping side of a conventional fork with a T/A might keep it from "racking" for lack of a better word and possibly binding a bit on the bushings- allowing it to function as intended both "sides" working in unison? It seems to make sense in my head anyway-
    Hi yes you are on the right track.

    In car racing I have won lots of championships & set may hill climb records & was sponsered by Bilstein Shocks for years (& you don't get that if your a bunny ) & spent lots of time with shock dyno's

    For my hill climb car when changing the front shock shafts from 36mm outer Dia to 50mm with the same Dyno valving the car handled so much better ( I broke the Hill record by 3 seconds ) because the shock shaft was stiffer had less binding on bearings & also held the wheels in the right place & so much more.

    I see the none under standing people trying to justify why they don't run T/A but in short they are trying to look at 1 side of a 100+ sided thing.

    There is little point Trying to get someone that Knows so little about how things work & try & debait 1 part of it.

    A T/A fork will work better in almost every way than the Std QR for so many reasons.Including how it uses its travel because it is less likely to bind up the bushing but the people that know nothing & have there forks setup wrong will simply think that the binding is good because the fork doesn't bottom out.

    My point is a wise man can't win a debait against a fool if the fool can't see his point.

    Note with the 2 front struts I was talking about that the shock dyno said worked the same,had we been able to side load the unit at the same time i'm sure from other testing & different valving shock we tryed on the same day that the nett result with the 36mm vs the 50mm would have been more than 10% softer in valving on the 50mm than the 36mm just in binding alone.
    I have a 6 Berth & 2 Berth Motorhomes that I rent out . They are based in Tauranga, New Zealand

  72. #72
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    Quote Originally Posted by mtn hack
    Boy, there sure are a whole lot of personal opinions (aka e-riding masturbation) stated as scientific facts in this thread.

    Show the numbers or go ride, but don't belittle others' opinions as being nonsense when they originate from the same place as yours; conjecture.
    Those are not conjectures. Those are observations. It is not random that all those engineering features that we have talked about make their way into production.

    You post, on the other hand, was nothing more then a rant.

  73. #73
    Life is Go0d!
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    By not being a clyde?
    The only regrets in life, are the risks you didn't take.

  74. #74
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    Quote Originally Posted by meltingfeather
    I know that's a lot to ask.

    Let me see what I can do. Got some transcontinental travel to deal with over the next few days, so bear with me...

    Cheers,
    Carla
    .........

    Peace,
    Niner Bikes

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