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  1. #1
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    Tech talk: Paging derby(and anyone else who

    wants to chime in:

    I am trying to make a decision on a 5" travel trailbike.
    I was originally going to go with the Motolite, but after doing 2 rides on a friends Motolite
    I realized that on very steep tight climbs the geometry wasnt right, I was feeling a little
    bit of lower back strain - I realized it was likely due to the very relaxed seat angle (which
    conversely helped on the tech downhills), so I thought, ok, I'll go with the Epiphany - its
    more efficient on the climbs and does the downhills almost as well as the ML(This is
    the info I was able to glean from those who have either owned both or ridden both.)
    But then, after coming across these comments from derby, I have some ques. about
    ICT and now am also considering the Mojo:

    Quote Originally Posted by derby
    Current ICT performance is worse than a quality monopivot design (although the high end platform shocks hide the difference well).
    I did note that in your post that you said you'd only ridden older ICT versions, but I was
    kind of surprised that you'd choose a quality monopivot - which has pedal feedback -
    over ICT which doesnt. Can you elaborate on what you don't like about the
    performance of the ICT suspension ? I've recently researched lots of reviews and forums posts looking for common themes - one is that the Epiphany doesnt need a platform shock, and in fact doesnt come with one unless you special order it, so I'm reading this as meaning that the Epiphany doesnt need "extra compression damping to mask suspension
    deficiencies", as _dw puts it. So I'm curious as to what, in your opinion
    makes ICT so bad. I'm trying to make a good purchasing decision, so if theres something
    I've overlooked about ICT, I'd like to know about it as I'll have to live with this decision
    for several years whichever one I choose. I'm honestly just looking for good info to help
    me decide, not trying to start a brand flame war as its unlikely that I will be able to try
    before I buy.
    Heres another quote from another suspension analysis:

    Quote Originally Posted by derby
    All other suspension designs than dw-Link (except possibly the NRS) have longer swingarms or longer path radius. The longer radius less curved path doesn’t accelerate the roll of the wheel as quickly or as much when compressed while coasting. FSR’s are nearly the same as a monopivot path until very deep in travel, ICT are monopivot in path, VPP is mostly mildly rearward to vertical in path, and higher forward monopivots like the Heckler are completely rearward in path.

    It’s commonly known that the rearward path rolls fastest through bumps at higher speeds, and the more vertical and lower monopivot type paths are the most smooth at lower to medium speeds.

    The overall downhill advantage of the dw-Link’s more rapidly forward compressing path (besides elimination of pedal feedback from chain tensioning better than any other) is best brake modulation in handling bumps and more powerful braking without traction losses. The rebound of the path direction is rearward and inversely relaxes or slows the wheel’s rolling speed as the wheel needs to slow in to being even with frame speed after the bump induced acceleration before the next bump. Traction dynamics are easier to maintain when the wheel speed is maintained closer to ground speed.
    From the animation from the dw-link site, the rear axle path looks somewhat like an
    upside down J, somewhat rearward at first, but not that much really, then forward at
    the end. Isn't this also similar to a quality monopivot at the beginning of travel ?
    I can see how the dishing action of the dw-link rear axle path works to smooth out
    the rate of pedal feedback. It still has it its just not as noticable. The physics of the
    susp. would work with the pedaling forces to minimize it.

    But maybe I'm mistaken, but I always thought the Horst-link type bikes were pretty
    much vertical ini their axle path, the FSR types having a very shallow rearward arc.
    (I ridden FSR and Motolite)

    I havent been able to look at any demo on this but as far as I can tell, with all monopivots, ie SC superlight, heckler, since the rear axle remains at a fixed distance from the BB, the rear axle path will have a semicircular forward leaning arc, nothing at all like a Horst-link bike, ICT or not, which arc relatively little in comparison.
    Actually, I'm not 100% sure about the monopivot path. Above you say the heckler is rearward,
    perhaps you're right - then the superlight would probably be rearward also, just less
    dramatically so. After taking a look at a demo, the FSR and ICT both look like the have very shallow rearward arcs, the ICT perhaps a tad shallower to the point of being nearly vertical. The faux bar looks to be more similar to a monopivot, although without being
    able to see a demo of a monopivot in action, its hard to tell exactly what the monopivot
    path is.
    Wondering what your thoughts were on this. Throw as much tech into the mix as you need to, I will try my best to digest it.

  2. #2
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    The short answer is ride the dw-Link and feel the difference to other rides.

    If you like firm shocks, and many riders do for more drift and sharper feedback from handling corners for a sensation of greater speed, then nearly any suspension design will do well with the current trend of firm compression damping and auto-lockout platform types of shocks such as Fox Propedal, Cane Creek, Fox Inertia Valve, and SPV. The firm compression damping packs-up the suspension in bumps and reduces squat from acceleration and when climbing up an incline. For this (cheap) sports car like handling simply look for a steep seat tube angle 73 to 74 degrees to position over the pedals easily while climbing in the seat, with a comfortable frame size for a comfortable fit, the suspension design really doesn’t matter much.

    But if you want a quick accelerating bike that is also freely bump compliant with a higher traction ride that grips the ground and handles corners so smooth and easily that you don’t realize how fast you are going until you have to brake for a tight corner, then look for a design that is not dependant on firm shocks for stability and pedaling efficiency. There are only a few original designs that accomplish this. The first was the significantly lower than drop-out positioned pivot Horst link. Later the trademarked VPP s path improved acceleration efficiency, but at a cost of losing some larger bump compliance when climbing and increased rear brake chatter from more suspension compression reactivity than a Horst link at the same travel. However, a VPP design can pedal efficiently with much more travel with similar stability and acceleration efficiency as a shorter travel Horst link, so the longer travel softer suspension equalizes the braking tradeoff and improves bump compliance overall in comparison to a similarly efficient pedaling shorter travel Horst link. There are other new designs that show improved performance in pedaling acceleration with little compromising trade-offs in other handling and braking requirements, such as the more weight shift sensitive multi-link semi-URT’s such as I-Drive, Maverick, the new Haro design, and the more asymmetrical link torque sensitive Felt Equilink.

    The dw-Link is the first major and complete step forward in performance with increasing travel for excellent climbing and trail riding since the well-balanced shorter travel Horst link variations in the ‘90’s and early this decade. The currently produced patented second generation dw-Link has absolutely no tradeoffs or compromises in seated and standing pedaling acceleration (without any discernable kickback), with deep bump compliance, stable handling, and high traction braking. The dw-Link suspension, much like VPP, does not squat lower when climbing, so the rider’s position remains easily over the pedals for efficient power input without excessive tugging on the handlebars or scooting up forward to the nose of the seat. And the seat position does not need to be exaggerated forward to compensate for losing a degree or more of seat tube angle due to climbing squat. But unlike VPP, when pedaling and hitting large bumps, the suspension relaxes and complies without negative pedal feedback, bumps feel like butter when climbing (like running 10 pounds less tire pressure without added rolling resistance), and momentum is not lost to a stiff suspension. And like a good Horst link, with IC not far forward of the weight center, braking is balanced, stable without stiffening the suspension, so traction is high without the rider exaggerating towards a rearward position shift. There are increasing numbers of suspension designs now aggressively copying the dw-Link designs without license and should ride with similar effects as the real thing.

    Other than spring and damping, weight shifts, and chain torque angle effects, path is the most significant factor in the dynamics of leveraging reaction from pedaling, and path is most significant in braking traction too. The FSR path near sag (since devolving from Horst link in ’02 and until readjusting geometry nearly back to Horst link this year), and ICT’s full travel path are nearly equivalent to a monopivot in the same place as the near bottom-bracket pivot. Pedaling reactivity is the same as a monopivot with the lower rearward main pivot of the FSR and medium low pivot of ICT bikes.

    For rear braking, a little known fact is that when an IC (or monopivot) is between the wheelbase the brake tension with the wheel leveraged with the suspension link(s) compress the seat tube, and vice-versa when the IC (never for monopivots) is outside the wheelbase the seat tube (or other attachment points for the suspension normally near the seat tube) is extended. FSR has a well-balanced IC position between the wheelbase near the weight center for balanced and freely active braking and stable handling. The problem with ICT is braking and handling, because the current version puts the IC so far outside of the wheelbase that while braking the bottom bracket and seat are leveraged in tension to rise, lifting the rider higher and exaggerating weight shift leverage around the front wheel center and increasing fork dive. Both Specialized and Ellsworth uses custom valved Fox shocks; either inertia valve or shim or orifice type for firmer low speed compression damping resistance, some type of platform shock. FSR and ICT using non-platform type shocks bob and squat excessively when pedaling without firm low speed shock damping (or over rebound damped non-platform shocks). A monopivot with the same pivot position of an FSR or ICT will require the same type of shock to pedal the same. But unlike ICT, a monopivot rear brake suspension does not extend the seat higher, a monopivot brake actually compresses the seat mildly and with stability so that handling is controllable by rider brake modulation, requiring much less repositioning of the rider weight during braking maneuvers. ICT might feel like you are going faster than other designs due to having less stability and firm damped lower traction shocks.

    Path matters when rear braking too. A rearward-compressing path is a forward-rebounding path, and vice-versa, a forward-compressing path is rearward-rebounding. Think about tracking a bump. When the suspension compresses between the wheel rolling up a bump face and the inertia of the rider weight, there is added tire grip and high traction as long as the suspension doesn’t bounce from too little rebound damping. But after compression when a wheel drops off the backside of a bump, the direction of the wheel while rebounding can improve maintaining contact if the rebound path is rearward (reaching back to the bump backside face) and contact is maintained while the tire is unweighted. There are variations in wheel momentum during rapid travel tracking bumps that can also complement braking from inertia when the compressing path is forward and rebounding rearward. This is valuable conservation of traction for slower speed brake modulation. But for higher speed downhill speeds the backside bump traction doesn’t matter much and a more constantly rearward compressing path such as a high monopivot has less resistance to speed. Higher speed downhill traction is gained mainly on the bump faces. For mostly medium to lower speed technical trail riding we find better braking with a path that decreases in rearward direction or increases in forward direction for best braking modulation control. Combine higher traction braking path with a balanced near weight centered IC tension to the frame for the best handling performance and the most usable rear brake power. The Horst link produced a short radius path centered well behind the seat tube that produced an ideal braking path in combination (usually) with an IC near the weight center of the bike. The dw-Link also produces a similar combination of ideals for braking. Low monopivot is next closest in ideal for rear braking, and most other designs are less ideal than these for technical trail handling.


    Racing success proves high performance. No pro has ever won a major national race event on an ICT bike. After 6 years in production any ICT performance superiority is still just a sales claim but unproven by racing or other testing. FSR cross country racers such as Ned Overand always used lockouts or near locked out shocks to XC race. Horst link has done very well in downhill racing. I-Drive has only had some downhill success. VPP has had little pro level success. While some of the same riders on dw-Link suspension has quickly proven it to be a dominant performance leader at the professional national and world level.

    In conclusion, get a ride on a dw-Link and feel the difference compared to other rides.
    Last edited by derby; 02-13-2007 at 12:25 PM.

  3. #3
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    Great discussion. VPP and dw-link both use low compression damping, and in fact
    Ibis and SC both recommend the same PSI in their rear shock, relative to rider weight.
    It would be interesting to know how much compression damping comes
    stock in the Ellsworth, as they just use the non-platform Fox Float,
    unless you upgrade to the RP23.
    I think your statement here summarizes the problem with ICT:

    Quote Originally Posted by derby
    The problem with ICT is braking and handling, because the current version puts the IC so far outside of the wheelbase that while braking the bottom bracket and seat are leveraged in tension to rise, lifting the rider higher and exaggerating weight shift leverage around the front wheel center and increasing fork dive. Both Specialized and Ellsworth uses custom valved Fox shocks; either inertia valve or shim or orifice type for firmer low speed compression damping resistance, some type of platform shock. FSR and ICT using non-platform type shocks bob and squat excessively when pedaling without firm low speed shock damping (or over rebound damped non-platform shocks)
    If the IC is far in front of the wheelbase while braking, that would make handling
    more difficult. According to the Ellsworth demo, the IC goes farther in front of the
    wheelbase the farther into the travel the suspenssion goes, but when the
    suspension is at sag or at normal position the IC is in the perfect spot, right
    behind the front wheel. The IC in front of the wheelbase would presumably be a
    boon while climbing, which, if I'm reading this correctly, is where the IC moves
    during climbing on an Ellsworth. Actually, it also seems to not squat that
    much into its travel during climbs, the climbing squat seems to be smoothed out
    on the current ICT versions, check out their demo here :

    http://www.ellsworthbikes.com/ict_demo/main.html

    Again, thats assuming I'm reading this correctly - the opposite would be true going
    down, which I think is where your comparison to a bad monopivot comes from.
    (This does seem to be bourne out in the claims of Ellsworth
    owners that the design bobs much less than an FSR on the climbs, though, and in fact
    Ellsworth does not ship a platform shop with their bikes.)

    Here do you mean bump reactivity rather than pedaling reactivity ?

    Quote Originally Posted by derby
    Pedaling reactivity is the same as a monopivot with the lower rearward main pivot of the FSR and medium low pivot of ICT bikes.
    If not, please explain.

    Here's another thing:

    Quote Originally Posted by derby
    But after compression when a wheel drops off the backside of a bump, the direction of the wheel while rebounding can improve maintaining contact if the rebound path is ! rearward (reaching back to the bump backside face) and contact is maintained while the tire is unweighted.
    From what I can tell, the rebound path is not that much rearward of forward. It looks
    like the articulating effect of the ICT linkage pushes the rear wheel path mostly
    downward, not rearward, as you'd see on a (quality ?) monopivot design.

    Also:

    [QUOTE=derby]
    For mostly medium to lower speed technical trail riding we find better braking with a path that decreases in rearward direction or increases in forward direction for best braking modulation control
    [QUOTE]

    All in all, the ICT system looks to be mostly linear, again this is just from looking
    at the demo of the guy riding and the graphic. From looking at the dw-link graphic,
    the IC is very close to the BB while braking, which I'm assuming is where the dw-link
    superiority in braking traction comes from. dw-links rebound path is mildly rearward,
    not dramatically rearward like a (quality ?) monopivot.

    I'm not trying to make a case for or against the Ellsworth design, just trying to do
    some analysis and comparison.

  4. #4
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    I watched the demo. I didn’t listen to the audio.

    The graphic shows a red line from the middle of the rear link through the IC which has absolutely no relevance in mechanical physics to anything unless there was some tension input (force vector) directed at that point along the rear link and in the direction of the IC. Obviously there is never tension input directed at that mid point on the rear-link, so there is absolutely nothing physically relevant about that red line. There is a formula of efficiency or energy loss presented in the demo that is based upon a factor of that red line. So the energy loss formula also has no relevance to physical reality. All comparisons to other suspension designs energy loss are also falsely based on the mythical claims in the demo.

    The demo and the energy efficency claims of ICT even in the patent’s are as truthful as is Frodo’s ability to fly on brooms in the wonderfully hopeful Hobbit movies. We all love a fairy tale. And naive children cling to fairy tales until they have a better reference with reality.

    I have ridden ICT with non-platform shocks before the current trend to firm compression damping in the last few years. ICT suspension pedals and bob’s exactly like a monopivot in the same place. It does appear that the main pivot near the bottom bracket has risen to near the middle ring in the most current versions of ICT so that less damping is required to calm the pedaling bob, while pedal kickback is not increased to a noticeable level using firm compression damping. But the pedaling reactivity of ICT is still not any different than a monopivot “faux-bar” with the same main pivot location. Put the same sock off an ICT to a Kona of the same travel and the Kona will pedal the same and handle better.

    I’m pretty bored of the ICT myths. So I won’t waste anymore time commenting more about it.

    Go ride an ICT and then ride a Kona, also a FSR, a VPP, and a dw-Link. You may prefer the firmer shock dependant ICT or Kona monopivot type suspension or buttery hartail pedaling feel of the VPP suspension.

    The ride experience is what is important and we each have a different sense of what rides best.

  5. #5
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    I think the red line is just meant to be a point of reference. It looks like the lines
    they're using to calculate potential energy loss are the other 2 lines going thru
    the rocker linnk and the chain torque line. According to their graph energy loss
    is greatest when the two lines meet far in front of the bike or meet beyond the screen.
    Even according to this graphic, if it is indeed representative of potential energy loss,
    there's no way this suspension is going to be 1% energy loss, which is what
    Tony E. previously claimed. Its obvious that those claims were nothing more than
    marketing hype. No bike has 99% efficiency except for a road bike on pavement.
    Their potential energy loss graph for VPP is obviously way off.
    You don't see dw making ridiculous claims like this, which is one reason I'm
    looking at the Mojo. His claims seem reasonable, ie he claims that dw-link has
    pedal feedback, but it is well managed by other physical forces.
    I'm very confident that I'd like the Mojo, I'm just nervous about getting a carbon
    fiber bike, as I live in Tucson, where many of the trails are littered with loose,
    sharp rocks. I don't want to have to avoid certain trails because I'm worried about
    damaging the frame.

    I'm not so sure I would go so far as to say this, though:

    Quote Originally Posted by derby
    ICT suspension pedals and bob’s exactly like a monopivot in the same place.
    For ex., the new Turners are monopivot faux-bar like the Kona. If you look carefully
    at some of the threads comparing the old Horst-link Turners and the TNT Turners,
    you'll find that the TNT versions dont have the same traction and small bump
    compliance abilities as the HL Turners. While the Ellsworth Horst link is
    not as low as the classic Horst-link, ie Titus, it is still chainstay, so it should
    not, theoretically at least, act like a monopivot most of the time.
    But you've at least ridden some earlier versions of ICT, so I have to take your
    assertion seriously, although there could have been other reasons why the bikes
    you rode bobbed. I think all 4 bar bikes without platform shocks will bob at least
    somewhat. According to some, the ICT is the most resistant of the 4 bars to bob,
    but you've put enough doubt in my mind about ICT that now I think I should find
    a way to demo or rent one first.

    Quote Originally Posted by derby
    But the pedaling reactivity of ICT is still not any different than a monopivot “faux-bar” with the same main pivot location.
    So if I do get a chance to ride an Ellsworth, what pedaling reactivity characteristics
    should I look for that are common to the faux bar ? (I've rented a faux bar a few
    years ago, so I could use that as a point of reference.)
    Anyway, thanks for your comments.
    I've noticed on some of the other forums that there is a bit of enmity towards
    Tony E. in general which I think can cloud the evaluation of his bikes.
    But since your comments focused only on the ride I'm taking them seriously;
    I'll definitely look to see what kind of valving they use on the non platform
    shocks that come stock on the bike, as I dont want to get a bouncy,
    high - compression valved bike.

  6. #6
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    Carbon fiber actually can be fixed rather quickly to look and be good as new by an experienced CF repair person for a low cost. It’s fixable much like a fiberglass surfboard dings are repaired. Minor dings can be fixed at home easily with epoxy, or other clear glue, and clear-coat paint. CF is very difficult to bend let alone break if thrown off a rock cliff or just landing hard on a sharp rock. While if a metal frame suffered as severe a hit the tube could be bent just a little and pull the whole frame out of alignment and full replacement is the only option for repair. The Mojo crash replacement cost is about $250 per CF unit.

    I have no fear of CF failure with this frame It’s build beyond industrial strength and is still the lightest 5.5 inch frame available. You’d need a frame at least twice as heavy in metal to be about the same in durability.

    Try riding a few different bikes with an RP23 shock and set the platform lever to the minimal setting. As far as I know there are no OEM tuned RP23’s. You can sense the differences in suspension reactive best with the least damping settings. The PR23 is actually rather firmly damped compared to high-end shocks at the minimal compression damper settings, but some noticeable contrasts between bikes can be made when riding hard.

    Try Titus bikes for the only high-quality Host link 4-bar in the US now.

    And demo a Turner 5 Spot. The new Mojo handles corners nearly the same as the 5-Spot, only it feels lighter and is much quicker.

    And visit the Turner forum for the most enthusiastic and experimental rider group. All expert Turner riders report the new monpivot rides at least just as well as the previous 4-bar ICT licensed designs. On the Turner forum only one rider has reported some placebo affection riding the 4-bar design back to back with the new monpivot links only in a very unusual deep gravel situation. Bushing pivots are superior for monopivot and the similar ICT type flatter-curve path designs, bushing pivots complement platform air shocks very well.

    Another very impressive and lightweight monopivot is the Yeti 575. It rides much like the Moto-light, but more plush and buttery, and very quick and easy to handle in anything.

    Enjoy the journey!

  7. #7
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    Quote Originally Posted by derby
    All expert Turner riders report the new monpivot rides at least just as well as the previous 4-bar ICT licensed designs. On the Turner forum only one rider has reported some placebo affection riding the 4-bar design back to back with the new monpivot links only in a very unusual deep gravel situation.
    There are many riders, myself included, and some of the press, notably the english press, objecting to the faux and you cannot really look into the Turner forum for objective evaluations (just compare the product reviews for the Turner pre/post TNT). A lot of "experts" in the forum used to be very belligerant about the superiority of Turner in respect to any bike because it was using a Horst. The same "experts" started to belligerantly claim that the Horst did not matter the moment Turner switched to faux and marketed it as a "new" system (T.N.T.) ... (litterally: a few days after Turner announced the TNT at interbike there were pages of reports appearing on the forum stating that it made no difference)

    But who cares!!!!! I just placed the order for my Mojo Medium Carbon I hope it stands up to the hype!!!! Two test drives were very promising!

    It should be here mid March and brake the sub-25 pounds barrier with some new light parts
    Last edited by Davide; 04-10-2007 at 07:05 AM.

  8. #8
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    Derby
    Would the new suspension on the Lapierre (french made bikes) be one of the closely related designs to the DW link, and if so ride similarly?
    Thanks in advance
    www.cycles-lapierre.fr

  9. #9
    _dw
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    Quote Originally Posted by dogvet
    Derby
    Would the new suspension on the Lapierre (french made bikes) be one of the closely related designs to the DW link, and if so ride similarly?
    Thanks in advance
    www.cycles-lapierre.fr
    It is a lot closer to VPP than dw-link. Basically the exact opposite of a dw-link in terms of anti-squat and braking performance. It would not ride like a dw-link.
    dw★link
    Split Pivot
    @daveweagle -Twitter

  10. #10
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    Quote Originally Posted by _dw
    It is a lot closer to VPP than dw-link. Basically the exact opposite of a dw-link in terms of anti-squat and braking performance. It would not ride like a dw-link.
    Well dw is obviously biased!

    And I haven't ridden the Lepierre design to verify my own perspective of path and effective pivot theory. But the Lepierre axle path is much closer to USA Trademark VPP 'S' curve (patented by Outland and now owned by Santa Cruz). The Lepierre path looks to be more progressively rearward in the ‘S’ curve, which might produce even more noticeable irregular pedaling feedback and suspension stiffening than the Trademark VPP, which I’ve ridden 4 or 5 different models and verify there is very noticeable feedback and problems with.

    While the dw-Link path is more closely like a Horst link’s tight radius round path progression/regression in chain tension. But the dw-Link is more elliptical in curve and quicker in transition from near sag anti-squat weight-balance into non-stiffening bump compliance during compression, and the rebound path also tracts the ground in bumps better than Horst link so better enhancing both pedaling and braking traction.

    I agree with dw that the bump reactivity is nearly as opposing as possible between the dw-Link and the VPP ‘S’ type path.

    I think the ‘S’ curve VPP makes a very good short sprint race platform. So does the dw-Link, but the dw-Link also excels in endurance riding. The feedback and suspension stiffening of the VPP (somewhat like high monopivot) beats up a rider more than a Horst link or somewhat similar lower monopivot over longer ride time.

  11. #11
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    Short lower links are good.
    Short stays are good.

    Get the Mojo frame only and build it up if the travel is OK for your needs.

  12. #12
    It's the axle
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    Here's another seat-of-the-pants review. I rode another 20 miles today. Everything from a couple of miles on asphalt to a ripping two mile downhill, to a very difficult several mile climb. Comparing this to my NRS Air, I have two comments. One is that this feels more like my road bike, in terms of efficiency. And unlike the NRS, there is absolutely no pedal feedback during suspension travel. None.

    There is another thing. My seat doesn't hurt. I cannot fault this bike in any way. From negotiating very tight uphill switchbacks, to the stiffness. It's a dreambike.

  13. #13
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    Derby
    It was always considered that Horst link (as in Turner) provided active suspension when pedalling and when braking, but if the new Turners (linked monopivot) work the same according to most riders, then one must assume that the previously held conviction are incorrect. Could one also assume that the "myth " of single pivots without linkage would be as active and not suceptible to all the faults they were supposed to have eg brake stiffening the suspension etc.
    Is the isolation of the rear axle ie Horst or short multilink the key to the start of "active suspension" or is it all very subjective.
    Thanks in advance

  14. #14
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    No myth but very boring

    Quote Originally Posted by dogvet
    Derby
    It was always considered that Horst link (as in Turner) provided active suspension when pedalling and when braking, but if the new Turners (linked monopivot) work the same according to most riders, then one must assume that the previously held conviction are incorrect. Could one also assume that the "myth " of single pivots without linkage would be as active and not suceptible to all the faults they were supposed to have eg brake stiffening the suspension etc.
    Is the isolation of the rear axle ie Horst or short multilink the key to the start of "active suspension" or is it all very subjective.
    Thanks in advance
    This is very old discussion: there are differences between a "Horst" and a faux-bar (I put Horst in quotes because there are many flavours of it, just for Turner the position of the chainstay pivot was different in a 2005 "horst" 5-Spot, Flux or Nitrous). It does not take much to notice the differences (push the bike on a rough downhill and grab a handful of brakes, or go on technical uphill anywhere you use a lot of travel to go over ledges, or steps). Are they big differences? No, and a "chocked up" pedal platform can further hide the differences - which might explain why a number of riders superficially state that there are no differences. My 5-spot had by far the best performance, in terms of "bump leveling" and traction downhill and uphill, with the RP3/PUSH in the "plushest" position: only problem was the pedaling efficiency in that setting. It is only with the Mojo DW-link that I (we) seem to get plush, traction AND pedaling efficiency.

    .. Foux or Horst? better? worse? for you to decide but to claim that a faux or a "horst" is the same is just a bit silly ... Kona, Orange, Foes and others "single-pivots" offer a floating brake option on their long travel bikes and they do that for a reason
    Last edited by Davide; 04-06-2007 at 10:27 AM.

  15. #15
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    Always seems quite interesting to me that so much difference can be felt on an 5" trail bike when sag is around 17mm out of a shock length of 56 mm. which only probably the middle 20mm anyone is caperble of peddalling through probably represented by 2" of travel at the wheel end?! Emporers new clothes possibly.

  16. #16
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    Quote Originally Posted by dogvet
    Always seems quite interesting to me that so much difference can be felt on an 5" trail bike when sag is around 17mm out of a shock length of 56 mm. which only probably the middle 20mm anyone is caperble of peddalling through probably represented by 2" of travel at the wheel end?! Emporers new clothes possibly.
    There are definite differences that 90% of riders cannot resolve. And I would like to agree that there is some placebo effect (real effect)... but

    1. On the Azure forum people see lot of travel while climbing on the granny gear, and one has to count the part before sag because that part gets used 'the most'. In other words, I am sure I pedal through 40mm of the 56mm... Especially blasting through
    (acellerating through) rock gardens.

    2. Acceptable low-bob sprint performace combined with no back pain the next day is an objective measure as are lap times.

    3.Down tube diameter has a mathematical correlation with sprinting stiffness...

    There are a lot of good things about the Ibis Mojo. DW- link is the most important of many many good decisions in this bike.

  17. #17
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    Quote Originally Posted by dogvet
    Derby
    It was always considered that Horst link (as in Turner) provided active suspension when pedalling and when braking, but if the new Turners (linked monopivot) work the same according to most riders, then one must assume that the previously held conviction are incorrect. Could one also assume that the "myth " of single pivots without linkage would be as active and not suceptible to all the faults they were supposed to have eg brake stiffening the suspension etc.
    Is the isolation of the rear axle ie Horst or short multilink the key to the start of "active suspension" or is it all very subjective.
    Thanks in advance
    Horst link performance varies from one design to another. Some produce a path nearly identical to a monopivot such as all of Ellsworth ICT that there is no effective difference in pedaling feel or performance to a monopivot in the same place as the main near BB pivot on the ICT bikes. Dave Turner reviled that his “horst link” bikes post model 2000 (after he raised the chain stay pivots an inch higher to avoid rear derailleur slap), varied from monopivot path only very deep in travel, below the range producing noticeable pedaling performance differences. So rather than fight Ellsworth for a useless patent license (of a Turner design Ellsworth copied to “invent” the ICT hoax… long story), Dave Turner went to monopivot linked shock design.

    There is a difference in handling balance and traction using a floating brake (such as Host link design). The IC of a floating braked link becomes the fulcrum of torque transfer to the frame, the monopivot is the torque transfer fulcum of a monopivot brake. (Floating brake IC torque effects are unlike pedaling effects where the wheel is not friction locked to the rear link – another long story is needed to explain the difference, there is no publication I know of that explains this at all, I’m considering writing one).

    In short when an IC is roughly about ½ way between the front axle and BB there is no frame tilting from rear brake induced torque (rider weight shift still upsets the frame, of course). Also when th eIC migrated during bump compression more rearward there in a dynamic increase during compression of the anti-lift of the seatpost end of the frame which complements stability and traction upon compression and rebound over bumps. Monopivots don’t have this dynamic leverage that well designed IC’s of floating brake systems can produce. (Path matters perhaps even more to rear braking traction, but that’s another long story.)

    The Turner braking was better with the ‘host link” style design, but the firmly damped shocks required for the poor execution of “horst link” covered up the advantage, so that the monopivot change made little noticeable difference if any to the vast majority of expert Turner riders.

    When rear braking and the IC is between the wheelbase, there is some amount of frame tension resisting extension while there is traction. The bottom-bracket compressing torque effect is more acute the closer the IC (or monopivot) is to the BB. When the IC is closer to the front axle then the more the compressing torque pull the front of the frame downward while rear braking. And IC in front of the front axle introduces a leverage that pulls the frame down in a direction in front of the axle causing a lifting reaction to the rear of the frame just as any lever does with a fulcrum (axle) in the middle such as a see-saw in a child’s playground. For example, the current Ellsworth ICT designs with IC’s far in front of the bike at sag actually jack the BB, crank, and seat upward while jacking the headset downward. These are the most unstable handling designs ever produced in mountain bike history (but the firmly damped shocks used cover up the instability fairly well for the unaware novice and intermediate full suspension rider duped by a long campaign of false advertising and that spending the most money buys the most performance).

    The more classic Horst links by Titus and the most progressive Horst links by Intense have a noticeable pedaling advantage over monopivot with low bob and active bump compliance, and excellent handling and traction while braking.

    Only the latest generation of dw-Link surpasses the overall balance of the very few best examples of Horst link.


  18. #18
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    So which out of the DW Link copies are any where near the origiinal eg Felt equilink, Maestro etc? in terms of performance.
    Thanks in advance

  19. #19
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    Quote Originally Posted by dogvet
    Always seems quite interesting to me that so much difference can be felt on an 5" trail bike when sag is around 17mm out of a shock length of 56 mm. which only probably the middle 20mm anyone is caperble of peddalling through probably represented by 2" of travel at the wheel end?! Emporers new clothes possibly.
    It starts to be a bit hard to figure out what question you are asking If you want to say that there are no differences between suspensions systems and people are imagining things Sure, you can say that, but 140mm of travel is a lot by any standard (you can run some downhill races with it): this is not a 80mm cross-country racer Put a non-platform shock on a 5.5" horst or faux bar and ...

    PS and I am not sure what do you mean by "which only probably the middle 20mm anyone is caperble of peddalling through " ...
    Last edited by Davide; 04-10-2007 at 10:11 AM.

  20. #20
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    Well the closer the suspension geometry is to dw-Link the closer is the performance.

    I’ve only seen a one picture posted in the Iron Horse forum not long ago that would appear pretty close to the patented 2’nd generation, ’05 model line of Iron Horse dw-Links. Perhaps the Independent Fabrications one-off dw-Link design was first to produce the patented version. Voodoo bikes had a prototype 29’er with a blatant copy of the patented dw-Link, but have not produced it for sale.

    BMC’s suspension draftsmen appear to have copied the first generation dw-Link of the Hollowpoint. BMC’s suspension is perhaps the closest in identical in dimensions and rates to the earlier produced Hollowpoint suspension.

    The Maestro in every size is nearly as close a copy as the BMC is to the Hollowpoint dw-Link. Their suspension drawer couldn’t be blind to the market and must have realized a good thing to copy while it was legally unprotected.

    The Felt Equilink design is not even close to dw-Link, and doesn’t perform with weight shift balance such as the dw-Link. It is a 6-link design with 7 suspension pivots (not including the pivot action of the axles). The Felt Equilink suspension uses flex stays producing a virtual “pivot” point near the rear axle on the shorter travel versions. Two of the 6 links look somewhat similar to a dw-Link, but the 6 link Felt design functions very differently and is unique to anything before. The Felt is a torque sensitive design which mainly uses pedaling chain tension to semi-lockout travel compression to reduce pedal bob. The dw-link is rider weight balanced in virtual swingarm coordinates throughout travel so that chain tension and chain angle within the normal gear select range makes only a very minor difference in reactivity.

    I image the legal business to enforce the patents will take many years. Defense commonly uses inexpensive delay tactics to wear down and bankrupt the plaintiffs into giving up the complaint. Also big businesses like Giant can covertly influence media and distributors to choke off DW products from the market by withholding Giant’s big dollar contracts if the media and distributors also accommodate the DW partner’s business. If DW and his licensed partners are careful to produce highly recommended bikes by customers and independent media. Their success will be rewarded in strong sales for many years. And independent distribution and media would grow in alternative to established businesses dependant on the old Giant business. The best the patents will do in the short run is suppress any future attempts to copy DW’s original designs without partner relations.

    Patents and enforceable regulatory law is an evolutionary step towards a more highly spirited humanity. Eventually there will be only positive law and personal and family self-control. We humans are still emerging from the jungle. Unregulated and commonly expected business ethic is jungle-like adversarial and predatorily based in a hunter and gatherer hording limited supply ethic. Someday business evolution will become more farming and agricultural like in planning for long-term abundance. We will then have plenty of choices and new ideas and new designs will be honored and promoted, not stolen.

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