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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
    Nightriding rules SuperModerator
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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 04:20 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.
    I’m 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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    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.

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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!
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  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.

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    I sure think this one is cool. Just sayn'.
    .
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    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 09:51 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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    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 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.

  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.
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  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.

  51. #51
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    Quote Originally Posted by Flystagg
    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.
    I think iheart did a great first swag at the analysis but like I stated in my posts it needs to be substantiate with mainstream analysis software coupled with hand calculations.....not forgetting a viable engineering test plan. Anything less is a SWAG with pretty pictures.

    I like my Ventana with the good, bad and ugly. I like Sherwood....he's a great chap. Like most posters here they may or may not understand all the physics behind FS bikes. That doesn't discount their opinion on the fit, feel or performance of any FS bike. It's an opinion.

    Since we're offering up design challenges here list up your half dozen things.......can you hand out hard calculations what you don't like or could better about your bikes? I don't think anybody here has their head in the sand....they are riding what they like for reasons told and untold. I personally would like to own a Turner if they did semi-custom front triangle changes like Ventana offers but they only offer color changes. So that puts Turner off of my list.

    It's been my experience as an engineer that it's very easy to criticize someone elses design when you're staring at hardware but a lot harder to come up viable ideas when you're starring at a white sheet of paper or blank computer screen.

  52. #52
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    Right on!

    Quote Originally Posted by mtnbiker4life

    It's been my experience as an engineer that it's very easy to criticize someone elses design when you're staring at hardware but a lot harder to come up viable ideas when you're starring at a white sheet of paper or blank computer screen.
    Very true. Since this is the internet, I'll throw in my 2 cents: I like the motivation of Iheart to try and quantify a feeling on the bike. How far off the numbers are...who knows.

    Though I am curious about Iheart referring to inertia and then talking about F=ma. Those two aren't the same. I'd think if you are talking about leverage ratios and antisquat, you have to be talking about moments of inertia. Which, now that I think about it...that probably is what he was talking about when he (or someone) referred to being about the bike's center of gravity.

    I also wonder if that software package is doing a static or dynamic analysis. Yes, a static analysis should give you a fair indication as to a frames ability to resist "bob." However, I'd argue that bob is a dynamic characteristic and doing a dynamic analysis...you need to consider the effect of rider weight shifts as well.

    Anyway, I'd say the qualitative sense of the analysis he did though does seem to mach my experience (though I guess limited). Last summer I rented a Heckler with an RP23 in Downieville when I had issues with the ring drive on my CK hub that couldn't be fixed while there. I have a pushed RP23 on my 07 X-5. The heckler with unmodified RP23 felt a lot stiffer under pedaling than my X-5. However, I liked riding my X-5 better, for whatever reason. Also, (I haven't asked Push this myself), but someone on here once had issues with their pushed RP23...felt it was too soft and bobing too much. They reported that after talking to Push...the usually tune down the platform on the RP23 for the Ventanas. So, that may explain why the heckler felt stiffer under pedaling. But again, I liked the ride of my X-5 (same fork on both bikes) much better than the heckler.

    And, FWIW, I just finished up my MSME and I've often thought about drawing up a frame in SOLIDWORKS and running an Analysis in ANSYS (which for me...modeling the rider input to the bike would be the biggest challenge). But, I'd rather ride my bike with my free time.

  53. #53
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    Uhhh. I have a Pivot and a El Cap and a El Rey. Engineering analysis aside, which I'm not qualified to perform, I have come to the conclusion that both designs have weaknesses and strengths. My PUSHed Ventanas feel better in the techy stuff. The Ventanas have better mud clearance. The Pivot and my old Blur packed up like crazy. Stiffness of the El Cap is unparalleled (I think). The El Rey and the Pivot are about equal as far as stiffness. The Pivot is a better pedaler. Not outstandingly so, but it is noticeable to me. I can tweak the Rey to be just as efficient, but then I lose the plushness. That being said, my Ventanas still put a smile on my face. I liked my Weyless XP either in AM or XC trim much more than the Blur I had at the time. The way a bike performs for a specific rider is much more important than graphs to me. That being said if the techno stuff turns you on, so be it.

  54. #54
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    WhereTF is uktrailmonster? And why hasn't he responded to this thread? That guy could shed some light on this pissing match.


    D.

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    + / -

    Does the selection of pivot location always involve compromises? If so, a good designer picks one which maximizes the positive aspects of that trade-off. I believe this to be true of all suspension designs, not just Ventana's. If he ends up with something satisfying the majority of users most of the time has he not chosen well?

  56. #56
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    I like my squatty ventana. I don't have extended fireroad climbs, I have ledgy, rocky, rooty climbs and I like a stiff rear end that is active.

    Is it less pedal-efficient? Sure.
    Is it more efficient to not have to use body english to get over everything? Sure!

    Hey, Iheartarguingaboutbicycles...you have your work cut out for you. You can throw as many scienticians at this as you can hire, but you aren't going to change too many minds that like their Ventanas...and that is the majority of the people on this very quiet board. Good luck with that. You held out pretty well, and starting a new thread was good (note that I haven't really chimed in due to the tone), but you digress again in insulting people. Not going to get sucked into that.

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    squat on climbs is well documented.

    Just another reference to it that I posted a long time ago:
    Quote Originally Posted by CharacterZero
    Saturday: 16ish mile ride. Good first leg to stretch out the legs and then lots of up/down/technical riding with a few creek crossings and steep switchbacks, followed by a sweeping descent that begs for little braking.

    The bike felt great! The TM is a stronger climber than the X-6 was (with the fork at any length). The front end was easier to keep on the ground, especially around uphill switchbacks. On the way down, the rear end felt very smooth, this was running both 5 clicks of compression and 0 clicks compression on the PUSH'd shock. (FWIW, PUSH removes the PP functionality - it is hard-wired based on rider weight/style. The PP lever then becomes a straight compression dampening function.). The performance of the shock is in line with what you expect from PUSH - it felt snappy on acceleration on the flats with minimal compression dampening, but wallowed a bit on the steeper stuff. Then again, I wouldn't sacrifice an active rear suspension for anything, so the bit of wallow is completely acceptable. The geometry is definitely a bit more drop-friendly; it took almost no body english to get the front end up while approaching ledges, just a slight tug. I didn't notice the longer wheelbase. Standover was fine (although close - but the wife says that it can only save us money on a vasectomy). BB height was noticeably lower (both in feeling just a bit lower and a couple pedal strikes in sections that I hadn't had before). .

  58. #58
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    Quote Originally Posted by CharacterZero
    I like my squatty ventana. I don't have extended fireroad climbs, I have ledgy, rocky, rooty climbs and I like a stiff rear end that is active.

    Is it less pedal-efficient? Sure.
    Is it more efficient to not have to use body english to get over everything? Sure!

    Hey, Iheartarguingaboutbicycles...you have your work cut out for you. You can throw as many scienticians at this as you can hire, but you aren't going to change too many minds that like their Ventanas...and that is the majority of the people on this very quiet board. Good luck with that. You held out pretty well, and starting a new thread was good (note that I haven't really chimed in due to the tone), but you digress again in insulting people. Not going to get sucked into that.
    I can't tell if people simply don't understand what I am saying or are reading into what I am saying - but I am absolutely NOT arguing against ventana bikes as a whole. I am explaining with a level of exactitude the reasons why the bikes squat. This thread is a response to many, many threads posted on the subject wherein several users try to ascertain what the problem is. The problem is very specific.

    With regard to technical climbs - you're absolutely right - my 6" travel bike is much better than either my 4" travel bike or even my hardtail - no question about it. I would even go so far as to say an active single pivot (in my case I have a Foes FXR, but it would probably hold true for the Ciclon and Terremoto as well) would climb better than a DW link!

    BETTER THAN A DW LINK!

    Because DW's stiffen noticably when pedalling, they do stiffen up and will skip a little over rocks.

    I have owned the DW's and can make this comparison directly. It's one of the reasons I dropped the DW for my "all mountain" bike.

    But with regard to a specific problem/question - the squatting that is so noticable with my Salty is directly due to the main pivot placement and lack of antisquat. So many other single pivots do not have this problem and that information is easy to come by.

    With regard to "digressing into insulting people" (sic) go back and read the thread - I've only used the term "fanboi" and suggested people keep their heads in the sand - meanwhile I am called several names and no one seems to think anything of those.
    Last edited by iheartbicycles; 09-23-2009 at 08:53 AM.
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    Quote Originally Posted by iheartbicycles
    With regard to "digressing into insulting people" (sic) go back and read the thread - I've only used the term "fanboi" and suggested people keep their heads in the sang - meanwhile I am called several names and no one seems to think anything of those.
    Sorry, you are correct, you don't insult anyone in this thread.
    No doubt there are some real fanbois around here.

  60. #60
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    Quote Originally Posted by mtnbiker4life
    I think iheart did a great first swag at the analysis but like I stated in my posts it needs to be substantiate with mainstream analysis software coupled with hand calculations.....not forgetting a viable engineering test plan. Anything less is a SWAG with pretty pictures.

    I like my Ventana with the good, bad and ugly. I like Sherwood....he's a great chap. Like most posters here they may or may not understand all the physics behind FS bikes. That doesn't discount their opinion on the fit, feel or performance of any FS bike. It's an opinion.

    Since we're offering up design challenges here list up your half dozen things.......can you hand out hard calculations what you don't like or could better about your bikes? I don't think anybody here has their head in the sand....they are riding what they like for reasons told and untold. I personally would like to own a Turner if they did semi-custom front triangle changes like Ventana offers but they only offer color changes. So that puts Turner off of my list.

    It's been my experience as an engineer that it's very easy to criticize someone elses design when you're staring at hardware but a lot harder to come up viable ideas when you're starring at a white sheet of paper or blank computer screen.
    I haven't forgotten about this and I still intend to check all measurements myself. My guess is you will once again raise the bar or change the level of proof required.

    That's ok. People who read this thread will make up their own minds. For me, I am always learning and you have actually caused me to think beyond what most people do.
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  61. #61
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    Quote Originally Posted by iheartbicycles
    I haven't forgotten about this and I still intend to check all measurements myself. My guess is you will once again raise the bar or change the level of proof required.
    The level of proof required is totally governed by how much creditability you wish to gain from the results you have put forth. Since, this topic is related to physics and engineering, I have mealy stated what you need to provide to be taken seriously in the engineering community. I am not saying your results are wrong and some on mtbr may blindly take them as absolute truth. But as an engineer, I have to ask for some test methodology if I am to take these results as reliable analysis.


    Quote Originally Posted by iheartbicycles
    That's ok. People who read this thread will make up their own minds. For me, I am always learning and you have actually caused me to think beyond what most people do.
    I’m a little confused about this statement. Because you have stated there are folks on this forum that do not understand the physics regarding this type of analysis so they really can’t make up their own minds, can they? I am sure there is a way to present this data so the lay-person can understand your methodology.

    -

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    Quote Originally Posted by mtnbiker4life



    I’m a little confused about this statement. Because you have stated there are folks on this forum that do not understand the physics regarding this type of analysis so they really can’t make up their own minds, can they? I am sure there is a way to present this data so the lay-person can understand your methodology.

    -
    Ventana fanboi's aren't the only people who read this forum. Those with an open mind and a little technical knowledge will see the thread for what it is.
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    Quote Originally Posted by iheartbicycles
    Ventana fanboi's aren't the only people who read this forum. Those with an open mind and a little technical knowledge will see the thread for what it is.

    Arm-chair engineer strikes head with hammer. Repeats. ?
    Since when did Need have anything to do with this?

  64. #64
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    Pro squat and proud

    ...of it.
    Attached Images Attached Images

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    I hear the new Squatnleavit Constipation is the ultimate anti squat.

  66. #66
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    Quote Originally Posted by tl1
    ...of it.
    tl1

    Brilliant! You have validated with undisputed scientific evidence the old adage that " a picture is worth a thousand words."

  67. #67
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    On the salty is there a difference when using 5" rockers over 4", with the correct fork travel up front?

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    So...Does this program really cost $199?
    I only ride bikes to fill the time when I'm not skiing.

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    Quote Originally Posted by OldHouseMan
    So...Does this program really cost $199?
    you can download trial software for free - but the full blown version ain't cheap.
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  70. #70
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    There is no magic bullet. Even if you have 100 pivots., ther is no getting around axle path/chain growth relative to the bottom bracket.(chain tension induced "anti squat") etc. Suspension performance is relative to the rider/style of riding. There are many types that have different charecteristics. Pick your poison. 1st gen VPP's have a lot of chain growth (chain tension induced "lockout"). So much so, that if set your chain up too short, compressing the suspension will rip the rear derailure off. Any suspension design can have a lot or little chain growth. The only thing unique I see about DW, is the chain growth has been tuned to be chainring dependant (or at least more so than other designs). That's why the man himself says the hammerschmidt will not work well with his design. Although I'll bet it works just fine for some people. The terrain on this planet as well as riding styles are too diverse for any single design to be "better" than another. This doesn't even take execution of the design in to account, which is a huge factor in performance.

    my .02

  71. #71
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    This is very well put. Each rider will have preferences and a riding style that is met better by one design over another.

    Your $0.02 is in reality, the gold standard.
    My presence would be the equivalent of painting lamb's blood on your frame, causing the "angel of crash" to nail me instead.

  72. #72
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    Oh yes, climbing a La Bruja? Either dial in so much propedal that the shock doesn't work, or suffer the squat, the bob and the pedal strikes.
    ~ Downride and Freehill, nothing else ~

  73. #73
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    Quote Originally Posted by Gruntled
    Oh yes, climbing a La Bruja? Either dial in so much propedal that the shock doesn't work, or suffer the squat, the bob and the pedal strikes.
    So answer this question - did you test ride the Bruja before you laid down that much cash? With all the shops and the Ventana demo program it's hard to put blame on the frame when it didn't work for you. I don't ride a Ventana because I'm a local "Fanboy" I ride one because it works for me. I also have other branded bikes. If I were to consider spending $2500 on a frame, better believe I would be taking a long hard demo or buy used.

  74. #74
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    Quote Originally Posted by iheartbicycles
    Ventana fanboi's aren't the only people who read this forum. Those with an open mind and a little technical knowledge will see the thread for what it is.
    I have never owned a Ventana but I can tell you that I'm a big fan. I could care less about anti squat theory. If it fits and feels good..it is good. The whole is the sum of the parts and that seems to be the main reason why the vast majority of Ventana owners are happy with their rides.

  75. #75
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    Quote Originally Posted by ronny
    . If it fits and feels good..it is good. .
    Did you miss all these threads?

    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?

    Ventana's bob worse than just about any other bike out there. They have lower antisquat than any bike I know of. Yet all the Ventana fanboi's answers to the problem is to run tons of compression damping (propedal) to hide the problem.
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    Read em all and you seem to be the loudest voice on each thread. I know what you are getting at and you actually come across quite logically in most of the threads. Ventana bikes are single pivot and the pivot placement is pretty much the same on all the bikes except the dh model. I know that Ventana is going to bob a little more than most brands with a higher pivot placement or different suspension design. With that said, the vast majority of Ventana riders are happy with their rides. As said previously, the whole is the sum of the parts. Always a compromise.

    One thing I am wondering is there is rarely any complaints about the Terremoto with excessive bob or squat. The pivot placement seems pretty low. I wonder if there is less complaints because Terremoto riders are using coil shocks or what? Does the extra travel mask the problem or would the bike not wallow in it's travel even more? Moto users please chime in. IheartVentana, what are your thoughts?

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    ****????

    This is why i ride a hardtail....

  78. #78
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    Quote Originally Posted by ronny
    Read em all and you seem to be the loudest voice on each thread. I know what you are getting at and you actually come across quite logically in most of the threads. Ventana bikes are single pivot and the pivot placement is pretty much the same on all the bikes except the dh model. I know that Ventana is going to bob a little more than most brands with a higher pivot placement or different suspension design. With that said, the vast majority of Ventana riders are happy with their rides. As said previously, the whole is the sum of the parts. Always a compromise.

    One thing I am wondering is there is rarely any complaints about the Terremoto with excessive bob or squat. The pivot placement seems pretty low. I wonder if there is less complaints because Terremoto riders are using coil shocks or what? Does the extra travel mask the problem or would the bike not wallow in it's travel even more? Moto users please chime in. IheartVentana, what are your thoughts?
    There's any number of reasons why terromoto riders haven't voiced concerns as much - including coincidence.

    Being that all ventana suspension bikes other than the cuervo have identical wheels paths, there's no reason to think the terremoto has any different characteristics than the salty, ciclon or bruja.

    Yep, I've been pretty vocal on this forum. My goal is to fight ignorance. It's harder than I thought!
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    Quote Originally Posted by iheartbicycles
    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.

    I've been avoiding this thread cause it looked like math was involved. . .

    But, it's pretty interesting, actually. I appreciate these points above. My impression was that the old Turners and the Ventana XC/trailbikes had pivots as low and close to the BB as they do to improve pedaling efficiency in the 22t ring up front while maintaining stiffness through to the rear-wheel. This certainly mirrors my trail experience as I ran 1x9 last year and 2x9 starting a month ago. The difference is noticeable to me climbing even with the same gear ratios. It'd be cool to know what the numbers were with 22t up front.

    Likewise, I wonder how the anti-squat changes through the sag. Intuitively, you're right, it should decrease, but I doubt it's a linear relationship for bikes with VP or DW links, as chain growth isn't linear on these bikes. I dunno, just sayin.

    Also, there are a lot of 0's plugged into the program (that I can see on the 1st pic anyway). Front and rear susp sag, etc. Wonder what these values do to the anti-squat number when changed to match real riding conditions?

    Lastly, is there an upside to the design that made Sherwood pick it? Is what I heard about the lateral stiffness and small ring pedal efficiency just bunk? Certainly the Propedal "fixes" the problem for my riding style, just wondering if there's an upside.

    Anyhow, I guess I did feel a bunch of squat on my Ciclon pedaling around in 32 or 34 up front and going up steep hills. Now that I broke down and got a granny, it seems to have lessened considerably. Now feels better than my last bike (FSR design), but much, much stiffer laterally.

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    Quote Originally Posted by Stripes
    Forget it. I'd rather go ride my bike than reply.
    bring your lights!
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    Quote Originally Posted by iheartbicycles View Post
    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.
    BUMP! Seemed the time was ripe.
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    because there is 1 thread that asks about comparison to dw.
    That and he is a bit of a bumper.

  83. #83
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    I would really like to see the curves posted at the beginning of this thread. It sucks that MTBR dumps not so old attachments now.

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    You can see the profiles of at least a few Ventana frames at Linkage Design

    Here's one of the new vs old Ciclón:


    Name:  Ventana El Ciclon 2012_Anti-squat.gif
Views: 219
Size:  23.7 KB

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    Thanks man!
    So, I assume that (32/15), is the gear combo for that anti-squat curve, which he seems to use as a standard for comparison. Wouldn't it be better to use a small ring gear combo (22/28 for example) since you would be most interested in anti squat during steep climbing?

    Now that I think about it, how much meaning does a graph like that even have?

    If you are comparing 2 different bikes, all you are really looking at is the amount of anti-squat in that gear combo, which might not be representative of any other gear combo, or is it?

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    You're right, but the site has lots more info on lots of bikes, including Alpino, Zeus, and El Cap. Here's another image for the "new" Ciclón:

    Name:  Excell.gif
Views: 201
Size:  7.9 KB

  87. #87
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    Quote Originally Posted by albeant View Post
    You can see the profiles of at least a few Ventana frames at Linkage Design

    Here's one of the new vs old Ciclón:


    Name:  Ventana El Ciclon 2012_Anti-squat.gif
Views: 219
Size:  23.7 KB
    that's a strange gear combo. I did most of my calculations at 32 front 30 rear. This gives a good feel for what's going on when you're climbing.
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    Quote Originally Posted by albeant View Post
    You're right, but the site has lots more info on lots of bikes, including Alpino, Zeus, and El Cap. Here's another image for the "new" Ciclón:

    Name:  Excell.gif
Views: 201
Size:  7.9 KB
    It is interesting that the A-S curves are completely different in the 3 chain rings in this example. In the large ring, A-S increases dramatically as you move to larger cogs. In the middle ring, A-S increases more gradually moving into larger cogs. In the small ring, A-S decreases as you increase the cog size.

    I can't really picture an explanation for those numbers, but it goes back to my point that an A-S number , or an A-S curve on a specific gear combo isn't that informative of a bikes performance.

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    Quote Originally Posted by smilinsteve View Post
    It is interesting that the A-S curves are completely different in the 3 chain rings in this example. In the large ring, A-S increases dramatically as you move to larger cogs. In the middle ring, A-S increases more gradually moving into larger cogs. In the small ring, A-S decreases as you increase the cog size.

    I can't really picture an explanation for those numbers, but it goes back to my point that an A-S number , or an A-S curve on a specific gear combo isn't that informative of a bikes performance.
    Isnt this brake squat and not antiquat?
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    Quote Originally Posted by iheartbicycles View Post
    Isnt this brake squat and not antiquat?
    I think the table is anti-squat (A1). Then the bottom of the table shows brake squat A2. Brake squat would be independent of gear combo I think.

  91. #91
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    Quote Originally Posted by smilinsteve View Post
    Thanks man!
    So, I assume that (32/15), is the gear combo for that anti-squat curve, which he seems to use as a standard for comparison. Wouldn't it be better to use a small ring gear combo (22/28 for example) since you would be most interested in anti squat during steep climbing?

    Now that I think about it, how much meaning does a graph like that even have?

    If you are comparing 2 different bikes, all you are really looking at is the amount of anti-squat in that gear combo, which might not be representative of any other gear combo, or is it?
    the Linkage program defaults to really weird gear combos. You have to choose the gearing you're looking for. And i agree - we're interested in climbing gears, not downhill gears.
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    Quote Originally Posted by Stripes View Post
    While I don't expect to understand the numbers, I can tell you that there is a HUGE difference in the pedal bob from going to a 1x from a 30T to a 28T. The 28T was so horrible that it lasted one ride before I switched back to a 30T (2012 Ciclon). My rear cassette was a 11-36, but even so, it's not clear to me why the feel would be so different between losing those two teeth.

    Could you expect in layman's terms why that would be the case?
    That is actually strange as generally, most SP bikes are designed to pedal better (more anti-squat) in smaller chain ring combo's than in larger. And honestly, 2 teeth is not alot. If I were to guess, and don't take this personally, it could be a sign of a poor pedal stroke. By spinning a little faster, in too small of a chain-combo, you are activating the suspension by weight shifts.

    I actually notice this myself. For example, when I ride my road bike, after a long hiatus, I often feel like I have "pedal bob" when I drop down to too low of a gear. Sounds crazy I know, but is a sign that my pedal stroke is gotten sloppy. There is of course, not "bob" but it feels very similar. And my dw linked bob actually makes me lazy and does not really respond to a bad pedal stroke. In contrast my old SP and HL bikes did.
    On MTBR, the reputation is infamous.

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    I agree the difference between 28 and 30 is small, but it sounds like 30 is "just right." Going to 28 may have increased or decreased anti-squat, (probably increased), but either way that can increase bob. To much anti squat can cause bob by extending the shock with each stroke.

    Also, remember pedal kickback is greater in lower gears (the crank turns more for a given amount of chain length).

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