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  1. #1
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    Relative Anti Squat Profiles Published! (finally)

    Thanks to a local engineer to helped my find the linkage program - here are a few anti squat profiles showing how ventana's stack up compared to a DW link and GT Idrive. These are just a few examples for refernce purposes only.
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  2. #2
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    Quote Originally Posted by iheartbicycles
    Thanks to a local engineer to helped my find the linkage program - here are a few anti squat profiles showing how ventana's stack up compared to a DW link and GT Idrive. These are just a few examples for refernce purposes only.
    Here's the ibis mojo...
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  3. #3
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    Not to discount your results or data but have you researched the credibility of the linkage program? Please post this so it will add credibility to your results.

  4. #4
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    Engineers, get a life and ride your bikes!!!
    Wait, first design some HVAC systems for me to inspect so I can keep working !!!

  5. #5
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    Quote Originally Posted by mtnbiker4life
    Not to discount your results or data but have you researched the credibility of the linkage program? Please post this so it will add credibility to your results.
    Nope! But I am glad you brought that up. I think a lttle scepticism is healthy. I do not vouch for the program, but it appears to be well accepted in the community. I would be interested to hear of any faults it may have.
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  6. #6
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    Here's what Dave Weagle thinks of the Linkage program:

    Quote Originally Posted by dw
    It makes me cry to see people comparing bikes with that Linkage program. As you've pointed out, unless someone measured the bike with a CMM, there is NO WAY THAT THE INFORMATION IN THE PROGRAM IS ACCURATE.

    As a matter of fact, with short links like used on the Revolt, or a dw-link, a difference of 1mm makes a completely different bike. The pictures of leverage rate curves in this message are not accurate, and nobody should be basing anything off of them.

    Dave
    http://www.ridemonkey.com/forums/sho...&postcount=393

  7. #7
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    Help me understand. BTW, there is no disrespect, no baiting, no nothing hidden in this post.

    Ok, now maybe some of this was addressed in the "other post" here on the Ventana board, but once things started downhill, I tuned out. I'm not interested in a war of words, or suspension design. I've ridden Ventana a long time, and haven't ridden a lot of other designs, so ignorance maybe is bliss for me. Also, for me and my riding style, I personally haven't had anything to complain about with my Ventanas. Yes, I goof around with my suspension settings, both shock and fork, when I get something new, but then I'm generally happy.

    Ok, now that that is out of the way. Help me here -

    Squat. Is this sag? If not, what is the difference?

    Ok, so Ventanas, or the suspension designs similar to Ventana, squat(?) more than other designs in order to achieve full usage of the shock? (I'm asking, I don't know, but I think this is what I was reading on the other post.)

    Ok, so this (amount of needed) squat is bad? Again, I don't know, but it seems that it is from this discussion. Its bad because? Is it bad because in order to get full usage of the rear shock I need to sag or squat so far into the stroke that I lose (effective) travel?

    Ok, so for example, the suspension design of the day (and no doubt it is good, I have friends that are running it and love it), the DW, does not (need to) squat / sag as much, because of the frame design, so you are getting more usage of your over all travel? AND not "bobbing" as much, because your shock is not as soft???

    Assuming that my understanding thus far is correct, does a design that "sits higher" / less squat / sag, have any issues with what I think of as "top out". I mean, does this design (i.e. DW) require additional rebound control, or is this a non-issue. Again, I don't know the answer, I'm just trying to picture the various suspensions actively cycling in my mind.


    Thinking back over the past 20 years or so of mountain bike suspension styles, there have been some very interesting ones to be sure.

    I always love to learn when it comes to bicycles, and suspension design is one place I need to study.
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    Stuff

  8. #8
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    one more thing...please use "print screen" to capture the screen (or Alt + PrnScn to capture only the active application) to the clipboard and paste it as a new image in your favorite image program, that would make them easier to read

    Thanks for the info

  9. #9
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    Quote Originally Posted by El Salt
    Help me understand. BTW, there is no disrespect, no baiting, no nothing hidden in this post.

    Ok, now maybe some of this was addressed in the "other post" here on the Ventana board, but once things started downhill, I tuned out. I'm not interested in a war of words, or suspension design. I've ridden Ventana a long time, and haven't ridden a lot of other designs, so ignorance maybe is bliss for me. Also, for me and my riding style, I personally haven't had anything to complain about with my Ventanas. Yes, I goof around with my suspension settings, both shock and fork, when I get something new, but then I'm generally happy.

    Ok, now that that is out of the way. Help me here -

    Squat. Is this sag? If not, what is the difference?

    Ok, so Ventanas, or the suspension designs similar to Ventana, squat(?) more than other designs in order to achieve full usage of the shock? (I'm asking, I don't know, but I think this is what I was reading on the other post.)

    Ok, so this (amount of needed) squat is bad? Again, I don't know, but it seems that it is from this discussion. Its bad because? Is it bad because in order to get full usage of the rear shock I need to sag or squat so far into the stroke that I lose (effective) travel?

    Ok, so for example, the suspension design of the day (and no doubt it is good, I have friends that are running it and love it), the DW, does not (need to) squat / sag as much, because of the frame design, so you are getting more usage of your over all travel? AND not "bobbing" as much, because your shock is not as soft???

    Assuming that my understanding thus far is correct, does a design that "sits higher" / less squat / sag, have any issues with what I think of as "top out". I mean, does this design (i.e. DW) require additional rebound control, or is this a non-issue. Again, I don't know the answer, I'm just trying to picture the various suspensions actively cycling in my mind.


    Thinking back over the past 20 years or so of mountain bike suspension styles, there have been some very interesting ones to be sure.

    I always love to learn when it comes to bicycles, and suspension design is one place I need to study.
    Actually if you tuned out Iheart and my discussion at the end, you missed out on some details on a killer Tahoe Ride...

    But first and foremost... No, Squat in the linkage program, is NOT Sag. Squat in this case is the force of the rider and bikes relative Center of Gravity moving backwards due to accelartion, causing the the suspension to compress ie Squat down. What I'm not sure about what the% means. But I'll assume the higher percentage number the more resistance to the "squat force" the linkage provide, what I don't know is percent of WHAT?

    Another concern along the lines of what Mtbk4life is bringing up, how were the numbers for the Geometry derived? I ask because I see a nearly 10mm error in the Salty #'s for the Chainstay alone. That's a 2% error to START with. Granted if that error is carried out thru ALL the frames the relative differences stay the same.
    EDIT : Not intended as critism or an attack, just trying to help in refining the numbers so they are more accurate.

    EDIT II : The main pivot of the rocker is shown placed BEHIND the seattube and the head angle is a steep 71.4 degrees. Iheart did you use a pre-2005 Salty?
    -A
    Last edited by Ciclistagonzo; 09-17-2009 at 05:20 PM.
    -Aaron G.

    "Before D.W., "anti-squat" was referred to as pedal feedback."

  10. #10
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    Quote Originally Posted by crisillo
    one more thing...please use "print screen" to capture the screen (or Alt + PrnScn to capture only the active application) to the clipboard and paste it as a new image in your favorite image program, that would make them easier to read

    Thanks for the info
    this software has security settings that don't allow this function.
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  11. #11
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    Worth Squat

    The rider's input to suspension performance cannot be measured by these plots- how he or she shifts body position and weight to get optimal performance. The best riders do not sit on their bikes like lifeless sacks of potatoes, they're dynamic and much less affected by these so-called theoretical limitations. The difference between the suspension system deemed "best" (whatever that is) and "worst" (ditto) is far less than the gulf separating a highly skilled pilot and even an average jockey.

  12. #12
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    Quote Originally Posted by Ciclistagonzo
    Actually if you tuned out Iheart and my discussion at the end, you missed out on some details on a killer Tahoe Ride...

    But first and foremost... No, Squat in the linkage program, is NOT Sag. Squat in this case is the force of the rider and bikes relative Center of Gravity moving backwards due to accelartion, causing the the suspension to compress ie Squat down. What I'm not sure about what the% means. But I'll assume the higher percentage number the more resistance to the "squat force" the linkage provide, what I don't know is percent of WHAT?

    Another concern along the lines of what Mtbk4life is bringing up, how were the numbers for the Geometry derived? I ask because I see a nearly 10mm error in the Salty #'s for the Chainstay alone. That's a 2% error to START with. Granted if that error is carried out thru ALL the frames the relative differences stay the same.
    EDIT : Not intended as critism or an attack, just trying to help in refining the numbers so they are more accurate.

    EDIT II : The main pivot of the rocker is shown placed BEHIND the seattube and the head angle is a steep 71.4 degrees. Iheart did you use a pre-2005 Salty?
    -A
    There aren't too many ventana's that have been plotted yet. THere is a 2007 Bruja showing the same antisquat as the 2005 salty. Being that pivot position is the same on the bikes (salty and bruja) and that antisquat is not a function of leverage ratio - I don't think it matters one way or the other.
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  13. #13
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    Quote Originally Posted by iheartbicycles
    Thanks to a local engineer to helped my find the linkage program - here are a few anti squat profiles showing how ventana's stack up compared to a DW link and GT Idrive. These are just a few examples for refernce purposes only.
    A few points of clarification.

    The numbers posted are all derived from a gear ratio of 32/30 - which I picked just cause it's a common climbing gear - but antisquat curves change based on gearing - so each bike will differ a bit based on this.

    Generally speaking, the lower the gear in the front - the more anti squat and the smaller (higher) the gear in the back, also the more antisquat. The converse holds true as well.

    Also - the anti squat posted for each bike is at top out - assuming sag of 20mm or so, each bike will behave a little differently. I haven't checked each - but of the ones I have (dw and ventana) antisquat decreases during suspension compression.
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  14. #14
    Nightriding rules SuperModerator
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    Quote Originally Posted by iheartbicycles
    this software has security settings that don't allow this function.

    bummer..I have the older version 2 and still allows it.....

    also..maybe the Alt+PrnScn may be blocked, but the one for the whole desktop should still work.... anyhow... too bad if it doesn't

  15. #15
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    Quote Originally Posted by Marshall Willanholly
    Here's what Dave Weagle thinks of the Linkage program:



    http://www.ridemonkey.com/forums/sho...&postcount=393
    That doesn't appear to be an indictiment of the program as much as the users. As the saying goes "garbage in, garbage out."
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  16. #16
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    Quote Originally Posted by Ciclistagonzo
    Actually if you tuned out Iheart and my discussion at the end, you missed out on some details on a killer Tahoe Ride...

    . What I'm not sure about what the% means. But I'll assume the higher percentage number the more resistance to the "squat force" the linkage provide, what I don't know is percent of WHAT?


    -A
    I believe it's a percentage of inertia. If you know the bike is accelerating at a certain rate you can configure the initertia of the bike and it's rider. My guess is antisquat % posted is the resistance to this.

    The error I see in this is you can't assume 100% antisquat means the bike is 100% efficient because it doesn't take into account the rider is not a perfect machine - in addition to the downward force on the pedals, (and we all do this) we all have a tendancy to bounce a bit as we pedal. So even a bike with 100% antisquat will bob a bit. More anti squat is required to counter the effects of inertia combined with rider induced bob.

    This is just my guess/understanding.
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  17. #17
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    Quote Originally Posted by iheartbicycles
    I believe it's a percentage of inertia. If you know the bike is accelerating at a certain rate you can configure the initertia of the bike and it's rider. My guess is antisquat % posted is the resistance to this.

    The error I see in this is you can't assume 100% antisquat means the bike is 100% efficient because it doesn't take into account the rider is not a perfect machine - in addition to the downward force on the pedals, (and we all do this) we all have a tendancy to bounce a bit as we pedal. So even a bike with 100% antisquat will bob a bit. More anti squat is required to counter the effects of inertia combined with rider induced bob.

    This is just my guess/understanding.
    That is what i assumed as well, but wanted to hear what others thought. I agree with your assesment about how we as rides are a dynamic being and are not a static force on our bikes. There is no 100% "efficient" design.

    Any idea HOW anti-squat is plotted by the program? I'd like to see the equation(s)

    Edit: Or a link to the program?

    -A
    -Aaron G.

    "Before D.W., "anti-squat" was referred to as pedal feedback."

  18. #18
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    Quote Originally Posted by Ciclistagonzo
    That is what i assumed as well, but wanted to hear what others thought. I agree with your assesment about how we as rides are a dynamic being and are not a static force on our bikes. There is no 100% "efficient" design.

    Any idea HOW anti-squat is plotted by the program? I'd like to see the equation(s)

    Edit: Or a link to the program?

    -A
    http://www.bikechecker.com/
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  19. #19
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    Do you have any...

    Diddley Squat profiles plotted?
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  20. #20
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    Quote Originally Posted by Stripes
    As a lay-reader and not a mechanical engineer..

    While this is an interesting discussion, what are we supposed to take away from this?
    This is simply a follow up on the many other threads where people have asked why their Ventana's squat so much while pedalling. Usually the people on the Ventana board recomend high levels of propedal and etc. This fix doesn't always work for one, and makes the suspension less active. When I brought up the idea that the suspension design itself was at fault, lacking in sufficient antisquat, it turned into an argument. So here you go.

    I like objective over subjective and empirical over ethereal. If after understanding this information you still love your ventana, that is fine - but this is the information I wanted to add to the conversation

    Quote Originally Posted by Stripes
    We all need Propedal or some type of compression to offset the squat? I mean, it comes across like iheartbicycles is trying to prove something about the DW link being so much better than the Ventana designs
    all the designs I checked had significantly more anti squat than the ventana. The GT Idrive actually had the most. Of the Idrives, the DHI had the most (200%)

    ,
    Quote Originally Posted by Stripes
    and not necessarily using current Ventana designs.
    Ventana has never changed their anti squat profile. Being that the bike is a single pivot and that the pivots are in the same place from year to year - plotting a 2005 vs a 2009 doesn't matter. But just in case, I did go and check on a 2007 and it has the same antisquat.


    ,
    Quote Originally Posted by Stripes
    Do you take into account any of the newer designs like the Bruja v2 or the Terremotto? What about running the bike with 30% sag (Sherwood recommends 30%) instead of 25% sag? Would that have an effect on the squat?

    I just ride bikes, not design 'em
    Yes, I did check one of the newer designs. The changes to the newer designs don't affect antisquat - they affect compression curves.

    With the Ventana's at 30% sag their antisquat decreases from an already low 45% to an even lower 37%.
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  21. #21
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    Quote Originally Posted by Marshall Willanholly
    Here's what Dave Weagle thinks of the Linkage program:



    http://www.ridemonkey.com/forums/sho...&postcount=393

    The program is 100% Accurate, the only problem is that pictures are not, they are always a little bit distorted, so the models are not perfect. If a bike has very small links the miskake is bigger, but it really depends on the picture that you are using to do the Linkage Model.

    If you use a "Full HD" picture, or a CAD Drawing you can build a very good model.

    I'ld love to see this kind of stuff posted by the original authors, and see how big are the mistakes that we are making but they never give this kind of information (Banshee is probably the only exception...). In the meantime, I'll keep using the program.

  22. #22
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    I've been riding a DW for the past 9 months and kinda miss the squat action of the Ventana under pedal load and braking. I like what it does to the geometry and handling of the bike. And on tech climbs the squat is not an issue. It's the long steep climbs where you have to remain on the nose of the seat for a while that bug.

  23. #23
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    Say(ing) what?

    There definitely is some bob going on with my plush X5, and on long flat climbs often I crank up some propedal and even lockout the Pike. The shock and fork don't seem to get warm so I doubt any significant amount of energy is being converted to heat. I do get a lot less beat up & rattled than some of my virtual pivot friends on high speed washboards and fast downhill rocks (e.g. Baldwin, Rocky Ridge). Also, I believe the compliance helps get up and over things nicely sometimes (nicer than my virtual buds). Haven't had the pleasure of a direct comparison ride w/ a DW, just w/VPP.

    Like Stripes, I'm still waiting for a direct statement of meaning from all this analysis. Are you saying a Ventana design wastes energy that a DW doesn't, or that it rides worse or harder under certain conditions, or doesn't climb well? Come on, we can handle the "truth" (as you see it).
    K

  24. #24
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    Quote Originally Posted by bayareamtnbiker
    There definitely is some bob going on with my plush X5, and on long flat climbs often I crank up some propedal and even lockout the Pike. The shock and fork don't seem to get warm so I doubt any significant amount of energy is being converted to heat. I do get a lot less beat up & rattled than some of my virtual pivot friends on high speed washboards and fast downhill rocks (e.g. Baldwin, Rocky Ridge). Also, I believe the compliance helps get up and over things nicely sometimes (nicer than my virtual buds). Haven't had the pleasure of a direct comparison ride w/ a DW, just w/VPP.

    Like Stripes, I'm still waiting for a direct statement of meaning from all this analysis. Are you saying a Ventana design wastes energy that a DW doesn't, or that it rides worse or harder under certain conditions, or doesn't climb well? Come on, we can handle the "truth" (as you see it).
    K
    My direct statement I thought was pretty clear. This thread is really a follow up to numerous other threads.

    The only thing I would add is the shocks spec'd on Ventana's generally are either the medium or high compression tune RP23's - which have significanty more compression than those spec'd on many other bikes. You will not achieve a more plush ride on a Ventana due to this, alone.

    Please note that I have included info on many non-dw bikes. The Idrive is notable as with regard to antiquat - it is a single pivot.

    I also ran numbers on Foes FXR - which came in at more than 100% antisquat for a simple, single pivot.
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    I think some people just beat on this issue way too much. I thought my El Ciclon climbed great. I used PP sometimes, lowered the fork sometimes for long climbs and had to be cognizant of my position on the bike when cleaning really steep stuff - but it's natural and part of the riding style. It wasn't an inconvenience. I thought the bike accellerated great - i like the way it squats into the travel when you get on it and hammer out of the saddle or brake into corners. I got full travel on pretty much every ride. Sure it can bob but that's why you learn to pedal smooth circles. My DW does a lot of things I like too and some things that I don't. There's give and take with every design. Ventana shouldn't change anything.

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    Quote Originally Posted by LncNuvue
    I thought the bike accellerated great - i like the way it squats into the travel when you get on it and hammer out of the saddle or brake into corners. I got full travel on pretty much every ride. Sure it can bob but that's why you learn to pedal smooth circles. My DW does a lot of things I like too and some things that I don't. There's give and take with every design. Ventana shouldn't change anything.
    Most peope do not like their bikes to bob and squat a whole lot. This is why every suspension bike company focuses so much on the issue - and it's why the subject is raised so often on the forums.

    Pedalling circles will in no way mitigate squat. Squat is a funciton of inertia - which you can't overcome without breaking a few laws of physics.
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    Quote Originally Posted by iheartbicycles
    Pedalling circles will in no way mitigate squat.
    You're right, rider position on the bike can mitigate squat.

    The good news is nobody is forcing you to ride a Ventana. So, why waste so much energy on the subject.

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    Quote Originally Posted by LncNuvue
    You're right, your position on the bike can mitigate squat.

    The good news is nobody is forcing you to ride a Ventana. So, why waste so much energy on the subject.
    Please tell me how your position on a bike lessens your inertia?

    The only way I know of to lessen inertia is to either accelerate slower or carry less mass.
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  29. #29
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    Quote Originally Posted by iheartbicycles
    Please tell me how your position on a bike lessens your inertia?

    The only way I know of to lessen inertia is to either accelerate slower or carry less mass.
    Iím not a physicist or engineer nor do I pretend to be one on MTBR.

  30. #30
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    Quote Originally Posted by LncNuvue
    The good news is nobody is forcing you to ride a Ventana. So, why waste so much energy on the subject.
    WORD!

    In the near future I plan to buy the linkage program.....certainly it is worth $199.00. It's cool that it allows the user to pull shared designs from the net but those designs need to be validated before publishing any results. garbage-in = garbage out

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    Most people?

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  32. #32
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    Quote Originally Posted by Stripes
    All your explanations to each of my concerns does not explain why you are looking particularly at Ventana anti-squat profiles. .
    It's exactly what I said: a follow up to several other threads.

    :
    Quote Originally Posted by Stripes

    You said Ventana has lots of squat, but here you're saying it doesn't. Which is it?.
    You're misunderstanding squat and antisquat. In the case of antisquat - a lower number (under 100%) is bad.

    Listen, Ann. I know you don't know me from Adam - so calling in Sherwood and chattering about "armchair engineering" just makes it apparent that you're swinging at windmills. I'm arguing basic physics. It's obvious the Ventana board is not used to this.
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    Quote Originally Posted by Stripes
    It's Anne. If you're going to talk down to me, learn to spell my name first. You don't know me from Eve, but if you're pushing a physics argument on why Ventanas are so bad, I'd like to hear from Sherwood, or any other full time bike designer. Since Sherwood designs the Ventanas, I think that's a very reasonable request.

    I'm trying to understanding why you're doing this on the Ventana forum, rather than going and whining on the NorCal forum like everyone else does there. People here tend to make sense to the non-engineering and engineering types who just want to ride their bikes and have fun.

    If you heart bikes so much, you should go out and ride instead of picking fights on a forum just because you're bored. The rest of us here (the Ventana forum) like posting why we like riding our bikes, not nitpicking what their imperfections are.
    I am sorry if you don't yet understand the physics behind suspension design. You're not alone, in the Ventana forum.
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  34. #34
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    Quote Originally Posted by iheartbicycles
    I am sorry if you don't yet understand the physics behind suspension design. You're not alone, in the Ventana forum.
    Chuck,

    I think it's safe to say that 90% of the people here have no idea what the hell you are saying. I sure don't.

    You are coming across as a cocky ass and you quite frankly aren't making your point a bit by being condescending to people.

    I'm just sayin'...

    Anyhow... I'm so fat and slow right now I'm barely qualified to lurk here. Back to lurking for me !!!

  35. #35
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    More to it than a graph

    Sometimes people can understand that there is more to a bike than the sum of it's parts and what it looks like on a graph.

    I'm sure I could come up with some other graph that shows you going forward more efficiently without the rear wheel wagging behind you like a dog in anything remotely off camber or technical. But I won't waist my time trying to convince anyone of it. Just ride the bikes and draw your own conclusions on whether it fits what you're looking for or not.

    I for one was sold, and am repeatedly sold over and over, on the overall frame stiffness of the Ventana's. The fact that they give up a little pedal efficiency over some other designs is not new.
    But I tell you, NOTHING I have ridden yet in 20+ years has delivered a bike that handles the rough stuff like the Ventana's do. I went through countless bikes just merely riding along dealing with the wiggly back ends in the rough stuff, thinking that's how all bikes were. But the first time in Tahoe on a demo Ventana years and years ago, I was hooked. I could take different lines, carve turns, accelerate(what? Accelerate? on an bike wiht such a low anti squat number on the graph? I must be crazy you say!.) out of turns with much more confidence.

    Now granted, I'm a big guy, 6'2" 240lbs, but I get this butt moving and I expect a quality bike frame that's retailing at $2200 plus, to do what I want it to. And you know what? Even with the new Turner, Ibis, Intense, SC variations of the beloved VPP and DW-link stuff, non can hold a candle to the rear end stiffness, and great front end layout, of the Ventana.

    Like I said, go ride `em. I encourage all my customers to go ride the different bikes and figure out what they're looking for and what works best for them.

    Remember, if we listened to Specialized, we'd all be using their dumb flexy FSR design because that was touted year after year as the most efficient way of getting power out fo the cranks to the rear wheel.

    For ME, the bike has got to hold it's line and go where I want it, not worrying about what some graph says.

    Can't wait for tomorrow....getting out and riding my oh so inefficient bicycle...probably have a smile on my face the entire time. It's RIDE TIME!
    Then it's a week of sin in SinCity. Booyaah!
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  36. #36
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    Quote Originally Posted by Internal14
    Even with the new Turner, Ibis, Intense, SC variations of the beloved VPP and DW-link stuff, non can hold a candle to the rear end stiffness, and great front end layout, of the Ventana.
    I have to disagree. The new DW Turner has an incredibly stiff rear end! I actually hold off camber lines through rough better than I did on the El Ciclon. The bike is an insane cornerer too. The slightly lower BB on the Spot helps a little as well. But I have to say the Spot is very stiff latterally, very stiff. The only difference I feel is that maybe the front triangle is not quite as burly as the Ciclons.

    On another note, I'm beat! Just did an 8 hr two man relay in Hurkey Creek today. We did 8 laps, 4 each and finished 4th out of 41 8 hr teams - 2 min off the podium. The 8 hr two man is tough and my first 2 laps were at 90*. I can pretty much guarantee the team 2 min ahead of us weren't riding 29lb trail bikes... I imagine carbon hardtails.

  37. #37
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    Quote Originally Posted by LncNuvue
    I have to disagree. The new DW Turner has an incredibly stiff rear end! I actually hold off camber lines through rough better than I did on the El Ciclon. The bike is an insane cornerer too. The slightly lower BB on the Spot helps a little as well. But I have to say the Spot is very stiff latterally, very stiff. The only difference I feel is that maybe the front triangle is not quite as burly as the Ciclons.

    On another note, I'm beat! Just did an 8 hr two man relay in Hurkey Creek today. We did 8 laps, 4 each and finished 4th out of 41 8 hr teams - 2 min off the podium. The 8 hr two man is tough and my first 2 laps were at 90*. I can pretty much guarantee the team 2 min ahead of us weren't riding 29lb trail bikes... I imagine carbon hardtails.

    I've heard others say that about the new DW turners too...but that's not what I felt. Maybe it was the wheel choice on the bike....

    WHAT?You actually RODE you're bike? Whoa there man. These things are meant to be looked at and discussed on the intrawebs....not ridden. For shame!
    www.velocitybicycles.comWhere customers become friends, not simply a dollar sign.

  38. #38
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    Empirically Speaking

    On the El Capitan, smoother pedaling visibly reduces rocker arm movement. And don't take my word for it, try that yourself.

  39. #39
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    Quote Originally Posted by iheartbicycles
    I am sorry if you don't yet understand the physics behind suspension design. You're not alone, in the Ventana forum.
    So far all you have showed us is that you can plug some numbers in a program that is excepted by the "community" and bash users. You have yet to show us that you have an expert knowledge or even a working knowledge of kinematic analysis. Yet you have shown us to have expert knowledge in being a jerk and a DH.

  40. #40
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    I sure think this one is cool. Just sayn'.
    .
    "...when your ride is nearly over, it seems to have lasted but an instant..."


    Stuff

  41. #41
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    Quote Originally Posted by mtnbiker4life
    So far all you have showed us is that you can plug some numbers in a program that is excepted by the "community" and bash users. You have yet to show us that you have an expert knowledge or even a working knowledge of kinematic analysis. Yet you have shown us to have expert knowledge in being a jerk and a DH.
    It's fun to see you all stick together and pat each other on the back. Meanwhile thread after thread after thread keeps popping up with riders asking why their ventana's squat and bob so much.

    El Salt Set-Up??? Horrible bob on steeps
    Moots-Ventana Suspension (Can PUSH save it?)
    Long travel and efficiency?
    How necessary is the platform on your Ventana?

    The usual answer from the forum is the same - use lots of propedal or push the shock. Which, in a way will reduce squat - but only by deadening the suspension.

    Many of you give answers completely off base. One user suggested running a smaller air chamber - ( I think this was internal14) if you actually thought about spring curves, you know this would only make the problem worse.

    Many users have blamed set back seat posts (I think this was lnc nuvue) - and even stated specifically that set back posts "negate antisquat." If you know anything about physics, it doesn't matter your position on the bike - it matters your mass and acceleration to determine levels of squat and antisquat.

    Users blame the fit of the bike in atleast 2 threads.

    Users blame the riders pedalling in several threads.

    I brought up pivot placement and correctly pointed out that ventana's have the lowest antisquat profile of any bike I've ever ridden. This is the core issue and is the reason why it keeps coming up.

    In each thread I post this, I get attacked.(ironically you guys claim that I make it personal - but I think all these threads show the opposite)

    In previous threads I did not have the data to back up my ideas - so this thread provides it.

    In the last thread I said that even faced with empirical data, the ventana forum would continue to keep its head in the sand - and you all are performing wonderfully in this regard. I expected as much.

    So now rather than analyzing the info provided, you attack me, you claim I don't know squat about squat, you suggest that offering up information that already existed is somehow lessons the truth of the matter.


    The truth of the matter is in the numbers - it has absolutely nothing to do with what you think of me.

    I don't expect to change your minds - I do expect the other members who read this site, will find this info beneficial. In fact I know this to be the case based on the many people who have come to me direct to have offline conversations.
    Last edited by iheartbicycles; 09-20-2009 at 10:51 AM.
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  42. #42
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    Great, another nerd-bike-stalker. Where's Gayem?

  43. #43
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    Quote Originally Posted by Ricky J
    The rider's input to suspension performance cannot be measured by these plots- how he or she shifts body position and weight to get optimal performance. The best riders do not sit on their bikes like lifeless sacks of potatoes, they're dynamic and much less affected by these so-called theoretical limitations. The difference between the suspension system deemed "best" (whatever that is) and "worst" (ditto) is far less than the gulf separating a highly skilled pilot and even an average jockey.
    +1 - read this again if you don't get it people. Moving my 165 lbs around a few inches effects the system a whole lot more than any frame design can.

  44. #44
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    Quote Originally Posted by iheartbicycles
    In each thread I post this, I get attacked.(ironically you guys claim that I make it personal - but I think all these threads show the opposite)

    In previous threads I did not have the data to back up my ideas - so this thread provides it.

    In the last thread I said that even faced with empirical data, the ventana forum would continue to keep its head in the sand - and you all are performing wonderfully in this regard. I expected as much.

    So now rather than analyzing the info provided, you attack me, you claim I don't know squat about squat, you suggest that offering up information that already existed is somehow lessons the truth of the matter.


    The truth of the matter is in the numbers - it has absolutely nothing to do with what you think of me.

    I don't expect to change your minds - I do expect the other members who read this site, will find this info beneficial. In fact I know this to be the case based on the many people who have come to me direct to have offline conversations.

    You have yet to show us that you have an expert knowledge or even a working knowledge of kinematic analysis. I want to see your hand calculations! Not results some from an obscure linkage software that has a few qoutes on its website from some "so called experts" here on mtbr.com. How about use a mainstream engineering software package like MathCAD, Mathematica, Matlab, or anyother MCAD software that has motion anaylsis.

    You will change my mind if you follow up with hand calculations and analysis from a creditable engineering analysis software package. But for now I will continue to ride my Ventana and work with any short comings it may have. I'm sure you will continue what you're doing........

  45. #45
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    Quote Originally Posted by mtnbiker4life
    You have yet to show us that you have an expert knowledge or even a working knowledge of kinematic analysis. I want to see your hand calculations! Not results some from an obscure linkage software that has a few qoutes on its website from some "so called experts" here on mtbr.com. How about use a mainstream engineering software package like MathCAD, Mathematica, Matlab, or anyother MCAD software that has motion anaylsis.

    You will change my mind if you follow up with hand calculations and analysis from a creditable engineering analysis software package. But for now I will continue to ride my Ventana and work with any short comings it may have. I'm sure you will continue what you're doing........
    Do you require this of all posters on mtbr or just the ones who don't agree with you?

    Do what you will with the information and analysis I provided.
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  46. #46
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    Quote Originally Posted by iheartbicycles
    Do you require this of all posters on mtbr or just the ones who don't agree with you?

    Do what you will with the information and analysis I provided.
    First, I havenít disagreed with you. Iím interested in your claims and the linkage software results but can no way say theyíre the absolute truth and 100% correct. There is some amount of error in those resultsÖ..what percentage I do not know. To validate your claims as with any good engineering analysis, publish the setup data and do some hand calculations or run those setups a mainstream analysis package. Then you can say with a good degree of certainty those results represent the performance of each frames linkage. But until you do that itís just a subjective opinion with pretty pictures from some obscure linkage software program.

  47. #47
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    Quote Originally Posted by mtnbiker4life
    First, I haven’t disagreed with you. I’m interested in your claims and the linkage software results but can no way say they’re the absolute truth and 100% correct. There is some amount of error in those results…..what percentage I do not know. To validate your claims as with any good engineering analysis, publish the setup data and do some hand calculations or run those setups a mainstream analysis package. Then you can say with a good degree of certainty those results represent the performance of each frames linkage. But until you do that it’s just a subjective opinion with pretty pictures from some obscure linkage software program.
    This would be fun to do - but honestly it's getting tiresome. Like you, I am always skeptical and I think this would be a good exercise. It's not going to happen today, though.

    BTW - do you know what software sherwood used to design the suspension of the ventana?

    When I worked in the industry only about 1/2 the company's used any software, relying on physical models instead. I've worked with many an engineer that weren't degree'd.Charlie Cunningham, Steve Potts, Mark Slate, Erik Koski, etc. Have spent a good amount of time talking with Brent Foes as well.

    None of these guys use FEA. They just break ****. Then before they put it into production, they make it stronger.

    I can't tell you who - but a very prominent bike company actually builds its suspension models starting with cardboard cut outs! These guys just have mechanical instincts and don't rely on computer models. I don't think that in any way discounts their capabilities.

    Would you require of them a CAD/CAM drawing with kinematic analysis?

    Software is only a tool used to speed up the process - it is not a process in and of itself.
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  48. #48
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    Quote Originally Posted by iheartbicycles
    This would be fun to do - but honestly it's getting tiresome. Like you, I am always skeptical and I think this would be a good exercise. It's not going to happen today, though..
    Agreed the anaylsis is not something that can be completed at a key stroke. I have 2+ years into some of my job related anaylsis. First, you would have to have all the critical measurements of all the frames which would require a NDA from all the frame manufactures. Or you get a tape measure that is +/-.001

    Quote Originally Posted by iheartbicycles
    BTW - do you know what software sherwood used to design the suspension of the ventana?
    I have no idea. I will let him answer that if he chooses.

    Quote Originally Posted by iheartbicycles
    When I worked in the industry only about 1/2 the company's used any software, relying on physical models instead. I've worked with many an engineer that weren't degree'd.Charlie Cunningham, Steve Potts, Mark Slate, Erik Koski, etc. Have spent a good amount of time talking with Brent Foes as well.

    None of these guys use FEA. They just break ****. Then before they put it into production, they make it stronger.
    I use to work with a lot of smart "older timers" at Lockheed that were not degreed engineers. A degree doesn't make someone smart it gives them a good tool box to work with. But someone has to have a good amount of smarts to get an engineering degree. I think the difference boils down to common sense.

    If you don't have an engineering degree you really are not an engineer. And in the State of California if you do not have a Professional Engineering License then you can't sell your services as an engineer.

    http://www.pels.ca.gov/licensees/pe_act.pdf

    Quote Originally Posted by iheartbicycles
    I can't tell you who - but a very prominent bike company actually builds its suspension models starting with cardboard cut outs! These guys just have mechanical instincts and don't rely on computer models. I don't think that in any way discounts their capabilities.
    I don't think so either as long as their product doesn't fail leaving folks dead. And it works. I remember the glamour of the 1990's the cottage industry were pumping out pretty CNC'd parts......with little or no analysis. I had a college buddy that was the test engineer for RS when they were in San Jose......Ohhhh the stories. The difference being Optimization or build not to fail

    Quote Originally Posted by iheartbicycles
    Would you require of them a CAD/CAM drawing with kinematic analysis?

    Software is only a tool used to speed up the process - it is not a process in and of itself.
    Santa Cruz bikes have been in numerous engineering industry publications for their design analysis. It's very cool to see bike companies using high tech engineering tools. It's one link in the design process that has to be validated. But the beauty is once you spend the time to input all the data it's very easy to "save as" and start on a new frame design.

    I became an engineering right at the start of parametric solid modeling.....Pro/E was the first to go main stream. I remember a seat costing $25K not including the UNIX workstation to run the software that was an additional $50K. So small companies were locked out of this market until 1998 when SolidWorks came to market with a $5K solid modeling software package that ran on a PC which made it affordable for a lot of smaller companies.

    http://www.ptc.com/products/proengin...-pro/index.htm

  49. #49
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    Is there just one single factor to having satisfaction in a frame one rides. Guess the Jet9 owners are satisfied having a recall as they have less anti-squat. DW Turner riders are satisfied having to break down their fames and add grease every month. Let alone only able to run certain crankests as not to hit the chain-stay because they may have less anti-squat. I admit I'm not a suspension guru! But what effect in this anti squat debate does running a coil versa air shock?

    Now I'm heavier than most around here and run my Pushed RP23 in PP mode. I noticed very little bob when pedaling as I do move to the front of the saddle. I also get full travel from my El Rey with 5 inch rocker. I don't doubt there could be frames that pedal better than a Ventana. But I'm just trying to understand why this is the sole reason one would choose one frame or another! For me there are frames out there that would flex all over the place as the Intense 5.5 EVP I had. I hated that frame yet it was a VPP and it should have less anti-squt than my El Rey.
    Currently at Mayo Clinic being tested for a kidney transplant. Donors welcome.

  50. #50
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    Iheartbycles, I just want to say good job bringing out real data, and sticking to your guns in the face of this much fandom, it is pretty obvious to any outside reader that most of the posters here are completely biased and unwilling to consider any negative traits of their bike. I personally can list off half a dozen things about each of my bikes that I don't like, or think could be better, but that doesn't mean they are still not the best bikes I've ever ridden, but if I find a new bike that fixes the problems of the old, then that is what I will be riding, I wont keep my head in the sand blind to other options, and other bike's strengths over mine.

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