Rear suspension designs

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  • 10-03-2007
    frank daleview
    Rear suspension designs
    Rememebr the days of emotionally charged discussions about rear suspension designs? In the past ~ten years we've seen:

    -Horst link proclaimed "holy grail" of suspension designs
    -the demise of the unified rear triangle
    -Stable platform valves breathing new life into the monopivot
    -seat stay "faux bar" vs. horst links
    -the reincarnation of the VPP
    -the DW-link

    Where are we now? Turner decides to switch to a seat stay pivot; Intense drops their line of horst link bikes in favor of the VPP. Specialized decides they really didn't have the "grail" and incorporate an inertia valve. Now the DW seems to be all the rage. Is horst still king? Will the monopivot survive the most recent barrage of innovations? What are the advantages/disadvantages. Which designs are here to stay and which ones are going to be joining the URT?
  • 10-03-2007
    Jerk_Chicken
    The HL will be around well after the patent expires. Most companies now and in the future are/will be using it only because of what people think. The UK press is especially harsh in this aspect. Anything that doesn't have a HL gets slammed.

    I don't think too many suspensions will die over the next few years. The reason is because a good ride never goes out of style or goes outdates. If it rides great and does what its supposed to do, it will last.

    I noted over the last few years that Stable Platform moved forward, got slammed, then the companies dialed the platforms back because people now complained about the suspension taking the lockout as priority over suspension performance.

    PS- HL is not a suspension design. It is a design element used in many different types of suspensions, from swinglink, modified strut, rocker, etc.
  • 10-03-2007
    TNC
    You know...Cunningham at MBA actually had something fairly wise to say on his editorial awhile back concerning the quality and diversity of the current MTB full suspension field. Basically he suggested that it's pretty hard to get poked in the eye anymore by a bad bike or bad design...at least with the bulk of the name brands available. I tend to agree with him. This discussion will never produce a definitive answer or a winner...just a lot of opinions. And that's good. In fact the main problem nowdays may be that there are so many choices that it's hard to pick the best bike for a particular rider in a particular set of circumstances. And bike/suspension setup may be the hardest thing a person has to come to grips with these days. And that's good. Choices are good...and when most of the choices don't suck, that's really good.
  • 10-03-2007
    darkest_fugue
    i only own one bike, its a full suspension, to be honest i think i still prefer a hardtail
  • 10-03-2007
    man w/ one hand
    Quote:

    Originally Posted by TNC
    You know...Cunningham at MBA actually had something fairly wise to say on his editorial awhile back concerning the quality and diversity of the current MTB full suspension field. Basically he suggested that it's pretty hard to get poked in the eye anymore by a bad bike or bad design...at least with the bulk of the name brands available. I tend to agree with him. This discussion will never produce a definitive answer or a winner...just a lot of opinions. And that's good. In fact the main problem nowdays may be that there are so many choices that it's hard to pick the best bike for a particular rider in a particular set of circumstances. And bike/suspension setup may be the hardest thing a person has to come to grips with these days. And that's good. Choices are good...and when most of the choices don't suck, that's really good.


    Wisest of the wise keepin' us grounded, AGAIN. Good stuff TNC. There is also the newer design of the pivot around the axel & incorperated into the drop outs. Can't remember what they're callin' it, not sure if it's an old concept w/new life or if it's all new.
    I agree w/TNC, that even with the lesser desired designs, you end up with a half way descent suspension to go through the woods with.
  • 10-03-2007
    mtnbiker72
    I think the DW-Link is the rage right now because its easier for manufacturers to acquire the rights to use it...and having owned one, it does work well. The FSR/HL design is very controlled by Specialized and they are very picky about who they allow to use it. The VPP design is also strongly controlled by Santa Cruz and so you only see them and Intense use it. Don't forget, there are several VPPish designs out there such as the DW-Link, Giant's Maestro, Haro's Virtual link, and Marin's Quad-Link...all patented as well. And not even mentioned but very viable is the floating drivetrain design ala GT/Mongoose/Schwinn and also Maverick...also patented

    -I think the mono-pivot will survive (remember, Santa Cruz tried to kill it in their bikes, and now they've brought it back) because of simplicity. Hard to argue having just one pivot to maintain.
    -I think as long as the FSR/HL pivot is patented, the Faux Bar Link will survive. If the patent ever expires w/o being renewed...then I think this design will fall out of favor. Not because its not still is a viable design (since it really acts the same as a single pivot) but because the FSR/HL pivot is better and a great selling point.
    -I don't think there will be very many "revolutionary" new designs anytime soon, just small tweaks to existing established designs. For instance, the new "split-pivot" designs from Dave Weagle and Trek are not revolutionary, just tweaks to Four/Faux Bar link designs.
  • 10-03-2007
    NormanPCN
    Quote:

    Originally Posted by iceaxe
    Where are we now?

    Same place we have always been. Suspension design is like religion. The history of religion A vs. religion B is documented and suspension A vs suspension B is really no different.

    We all need to find what we as individuals like and ride it. One might even like a different design for different diciplines. DH verses XC for example.

    For me I stumbled into what I like. It was a revelation in feel. Is it the suspension? The geometry? All of the above in combination? I don't know and I dont care. I just know I am going to ride it to death with a smile on my face.
  • 10-03-2007
    frank daleview
    Oh yeah, I forgot about the GT i-drive and maverick designs. Perhaps the URT isn't as dead as I thought.

    I'm really curious about Turner and Jamis ditching the Horst link in favor of a seat stay design. I can see Jamis being more concerned about the bottom line; but @ almost 2Gs a frame, I can't see Turner being concerned about that.

    I almost pulled the trigger on a Racer X a few years ago but I opted for Castellano soft tail instead. It's a fast ride but there are some times I really miss full suspension.
  • 10-03-2007
    MK_
    Pretty much all designs are here to stay, they may disappear briefly, like the VPP, to be brought back to life by a company that can market it better or tweak some engineering aspect. It all seems to be fueled by marketing and the invasion of consumer's perception of the latest and greatest and the company's desire to offer a unique product.

    Turner has built up a reputation of very high quality manufacturing, durability, fantastic customer service and good geometries with mass appeal. He also got involved in a feud with the dark side of mountain biking, Tony Ellsworth, who has cheated his way around FSR with his ICT patents and demanded premiums from Turner on top of the Specialized premiums Turner was already paying. You can imagine how ridiculous this must have been for Turner since Turner was involved in testing Horst Leitner's frames at AMP Research. Paying royalties for a design you were involved in developing to a wise thief would be very trying to a person. Now you can open up an even bigger can of worms when you start asking about Nicolai's involvement with the pivot we now know as the Horst Link.

    But without further ado, faux bar or four bar, Turner has gone to great lengths, aided by the faithful fraternity knows as the Homers, in proving that the bikes ride nearly identically, all things being equal, replacing the HL pivot with a seat stay pivot. Many companies, including Kona, Ventana, Yeti, Transition, etc. have shown that the most important aspect of the Faux bar linkage is the placement of the main pivot as that pivot is responsible for the pedaling characteristics of the frame and that is one essential attribute.

    The Faux bar evolves, slowly, too. Yeti has replaced a bearing pivot on the seat stay with a piece of carbon fiber and is charging more for the Faux bar frames than any other Taiwanese made frame, to my knowledge, employing that type of linkage. Kona's latest attempt at differentiating itself in the Faux bar market is the DOPE system, or, integrated floater. Trek has licensed Dave Weagle's simpler linkage design, called the split pivot, which essentially brings the seat stay pivot a little closer to the chainstay, where it is the most desired. Transition is keeping it simple and charging less money for the frames. Their effort appears to be focused on killer geometries, which they appear to have been able to achieve with each frame they have put out.

    VPP was originally developed by a couple of guys, an engineer, and a frame maker and the company that owned the original patents was Outland. The VPP linkage is interesting in that it requires a good amount of travel to work well. Outland's original design was falling rate to work well with air shocks, but long travel bikes, which benefit most from VPP's "sweet spot" or the area of travel where chain tension keeps it from bobbing, used coils, so the frames had a bottoming issue. After reading this interesting article (http://72.14.253.104/search?q=cache:...lnk&cd=1&gl=us) it appears that Santa Cruz didn't want to be a sole developer and introducer of the VPP linkage to the market and brought Intense on board to help them develop the linkage and to boost the intrigue of the consumer with an additional brand sporting the linkage. It is also interesting to note that Santa Cruz felt that Jeff Steber (the founder of Intense) was one heck of an engineer, and his input very important in development of the success the new generation of VPP linkage is.

    DW-Link is a new addition to the market. A market hungry for new technology, unique products, etc. Dave Weagle's linkage has been proven by Iron Horse, who emerged from the bottom of the pile mass manufacturer to a company producing very highly desirable bikes, some of which have been piloted to podiums of the World Cup Circuit. The roster of DW linkaged frame manufacturers includes Independent Fab, Ibis, and Chris Cocalis' (the guy behind Titus) latest company is utilizing DW-link exclusively on the frames. DW has also proven his engineering ability by tweaking FSR pivot locations on the Sunday's predecessor for Iron Horse, the SGS. The frame which was very successful in the DH circuit. You can also open up another can of worms when you start questioning whether Giant's Maestro and BMC's linkages have somehow been influenced by DW's work.

    It appears that the holy grail is a linkage which does not rely on stable platforms and allows the shock to move freely so that one does not have to compromise the DH performance for stable pedaling and vice versa. If there is one linkage out there which can facilitate the claim in sound engineering that's DW link. But in the end, the suspension design is just one element of the overall feel of the bike. The geometry, weight, durability, looks, etc. all play a role. In my mind, geometry is paramount. Proper angles and tube lengths can do more for the feel of the bike than the best linkage execution.

    _MK

    P.S. It is also worth commenting on Turner and the use of bushings. Bushings are fantastically durable and mountain bikes are such a perfect application. You see more old Turners on the market than any other brand. And frequently, they're running the original set of bushings. It appears that Banshee is going to be using bushings on their new frames and that's great news. I wish more manufacturers would follow. This is quite a contrast to Santa Cruz offering lifetime bearings for the original owners. The life of those bearings can almost be measured in weeks.
  • 10-03-2007
    Gregg K
    There are some good discussion in the Ibis forum on suspension right now. Even the patent holder, Dave Weagle, is contributing to the discussion.

    You won't find a single negative review of the DW link on the Ibis Mojo. I've only owned the NRS and the Mojo. But I'm absolutely thrilled with this bike. It literally does it all. And if you read the latest posts on shocks and rear suspension over there, you'll see why it's so good. Some suspensions are better at certain things like braking or larger hits. But the DW link on the Mojo really is set up to perform as the ultimate cross country bike, in my opinion. But that's just my opinion. After riding hard tails for twenty years, I wanted something more comfy. What I found was more than that. And it's a world apart from the NRS. I couldn't even get on that again. It's like being on a jacked up bike that's unstable.

    Also, you can see how posts over there include graphs of the different suspensions and their properties. Check it out.
  • 10-03-2007
    Trajan
    Quote:

    Originally Posted by mtnbiker72
    I think the DW-Link is the rage right now because its easier for manufacturers to acquire the rights to use it...and having owned one, it does work well. The FSR/HL design is very controlled by Specialized and they are very picky about who they allow to use it. The VPP design is also strongly controlled by Santa Cruz and so you only see them and Intense use it. Don't forget, there are several VPPish designs out there such as the DW-Link, Giant's Maestro, Haro's Virtual link, and Marin's Quad-Link...all patented as well. And not even mentioned but very viable is the floating drivetrain design ala GT/Mongoose/Schwinn and also Maverick...also patented

    -I think the mono-pivot will survive (remember, Santa Cruz tried to kill it in their bikes, and now they've brought it back) because of simplicity. Hard to argue having just one pivot to maintain.
    -I think as long as the FSR/HL pivot is patented, the Faux Bar Link will survive. If the patent ever expires w/o being renewed...then I think this design will fall out of favor. Not because it still is a viable design (since it really acts the same as a single pivot) but because the FSR/HL pivot is better and a great selling point.
    -I don't think there will be very many "revolutionary" new designs anytime soon, just small tweaks to existing established designs. For instance, the new "split-pivot" designs from Dave Weagle and Trek are not revolutionary, just tweaks to Four/Faux Bar link designs.

    Why is the DW system easier to acquire? There are only two bikes (soon to be three) that use this system currently.

    All these systems work well and all have drawbacks.

    I do think that when the Horst patent expires, we will see the end of the "faux" bar bikes.
  • 10-03-2007
    charlou61
    This is one of the most interesting thread i ever read!!
  • 10-04-2007
    TNC
    Bearing life in weeks?
    Quote:

    Originally Posted by MK_
    Pretty much all designs are here to stay, they may disappear briefly, like the VPP, to be brought back to life by a company that can market it better or tweak some engineering aspect. It all seems to be fueled by marketing and the invasion of consumer's perception of the latest and greatest and the company's desire to offer a unique product.

    Turner has built up a reputation of very high quality manufacturing, durability, fantastic customer service and good geometries with mass appeal. He also got involved in a feud with the dark side of mountain biking, Tony Ellsworth, who has cheated his way around FSR with his ICT patents and demanded premiums from Turner on top of the Specialized premiums Turner was already paying. You can imagine how ridiculous this must have been for Turner since Turner was involved in testing Horst Leitner's frames at AMP Research. Paying royalties for a design you were involved in developing to a wise thief would be very trying to a person. Now you can open up an even bigger can of worms when you start asking about Nicolai's involvement with the pivot we now know as the Horst Link.

    But without further ado, faux bar or four bar, Turner has gone to great lengths, aided by the faithful fraternity knows as the Homers, in proving that the bikes ride nearly identically, all things being equal, replacing the HL pivot with a seat stay pivot. Many companies, including Kona, Ventana, Yeti, Transition, etc. have shown that the most important aspect of the Faux bar linkage is the placement of the main pivot as that pivot is responsible for the pedaling characteristics of the frame and that is one essential attribute.

    The Faux bar evolves, slowly, too. Yeti has replaced a bearing pivot on the seat stay with a piece of carbon fiber and is charging more for the Faux bar frames than any other Taiwanese made frame, to my knowledge, employing that type of linkage. Kona's latest attempt at differentiating itself in the Faux bar market is the DOPE system, or, integrated floater. Trek has licensed Dave Weagle's simpler linkage design, called the split pivot, which essentially brings the seat stay pivot a little closer to the chainstay, where it is the most desired. Transition is keeping it simple and charging less money for the frames. Their effort appears to be focused on killer geometries, which they appear to have been able to achieve with each frame they have put out.

    VPP was originally developed by a couple of guys, an engineer, and a frame maker and the company that owned the original patents was Outland. The VPP linkage is interesting in that it requires a good amount of travel to work well. Outland's original design was falling rate to work well with air shocks, but long travel bikes, which benefit most from VPP's "sweet spot" or the area of travel where chain tension keeps it from bobbing, used coils, so the frames had a bottoming issue. After reading this interesting article (http://72.14.253.104/search?q=cache:...lnk&cd=1&gl=us) it appears that Santa Cruz didn't want to be a sole developer and introducer of the VPP linkage to the market and brought Intense on board to help them develop the linkage and to boost the intrigue of the consumer with an additional brand sporting the linkage. It is also interesting to note that Santa Cruz felt that Jeff Steber (the founder of Intense) was one heck of an engineer, and his input very important in development of the success the new generation of VPP linkage is.

    DW-Link is a new addition to the market. A market hungry for new technology, unique products, etc. Dave Weagle's linkage has been proven by Iron Horse, who emerged from the bottom of the pile mass manufacturer to a company producing very highly desirable bikes, some of which have been piloted to podiums of the World Cup Circuit. The roster of DW linkaged frame manufacturers includes Independent Fab, Ibis, and Chris Cocalis' (the guy behind Titus) latest company is utilizing DW-link exclusively on the frames. DW has also proven his engineering ability by tweaking FSR pivot locations on the Sunday's predecessor for Iron Horse, the SGS. The frame which was very successful in the DH circuit. You can also open up another can of worms when you start questioning whether Giant's Maestro and BMC's linkages have somehow been influenced by DW's work.

    It appears that the holy grail is a linkage which does not rely on stable platforms and allows the shock to move freely so that one does not have to compromise the DH performance for stable pedaling and vice versa. If there is one linkage out there which can facilitate the claim in sound engineering that's DW link. But in the end, the suspension design is just one element of the overall feel of the bike. The geometry, weight, durability, looks, etc. all play a role. In my mind, geometry is paramount. Proper angles and tube lengths can do more for the feel of the bike than the best linkage execution.

    _MK

    P.S. It is also worth commenting on Turner and the use of bushings. Bushings are fantastically durable and mountain bikes are such a perfect application. You see more old Turners on the market than any other brand. And frequently, they're running the original set of bushings. It appears that Banshee is going to be using bushings on their new frames and that's great news. I wish more manufacturers would follow. This is quite a contrast to Santa Cruz offering lifetime bearings for the original owners. The life of those bearings can almost be measured in weeks.

    MK, that's a fairly "all-inclusive" statement. That suggests all VPP bikes. While I might tend to agree with you to a degree on the BLT, the "weeks" assessment is even a little harsh for that model. I ran my Nomad OEM bearings from January '06 to March '07, and even then I only changed them because of paranoia before a pending trip to Moab...and I had a new Propack sitting on the work bench. And BTW, we don't have a winter where I live that really interferes with riding time. Those original bearings were still good, and with the exception of the BLT, this is the common experience through our shop. High end bearings and antiseized pivot axles seem to resolve much of the previous concerns on the VPP design. We don't have any Intense VPP models in our area, so I don't have any input on those.

    I would agree with you on the durability of the igus setups in Turner bikes...good stuff...but every bike I've owned with sealed ball bearings has yielded excellent service. In the case of the VPP, it was almost ridiculous to realize that just a simple antiseize application stopped the creaking and early bearing failure. Personally I would rather see bike manufacturers use needle bearing setups at critical pivots. There are a very few who do. These work very reliably on just about all motorcycles and are worth the small weight increase for the performance they provide.
  • 10-04-2007
    perttime
    Looks like more than just Foes may be starting to take shock leverage ratios seriously and moving from 3:1 towards 2:1.
  • 10-04-2007
    Steve from JH
    I find it odd that nobody has mentioned the Felt Equilink.

    It's the only design that allows plenty of anti-squat to be generated all through the gear range while at the same time having only minimal pedal feedback--at least for small to medium bumps.

    It allows for the use of a shock with compression damping optimized strictly for bump absorbtion without any regard to pedaling effects.

    When set up properly you can have maximum small bump compliance combined with completely bob-free pedaling as long as you stay seated.

    A shock with some kind of on/off switchable firm platform would be best if you want to do a lot of out of the saddle pedaling.
  • 10-04-2007
    NormanPCN
    Quote:

    Originally Posted by MK_
    In my mind, geometry is paramount. Proper angles and tube lengths can do more for the feel of the bike than the best linkage execution.

    I'll second that notion.
  • 10-04-2007
    Student Driver
    Trek actually licensed the ABP from DW? I thought that was a "coincidence" or something and still waiting for world patents to be sorted.
  • 10-04-2007
    Jerk_Chicken
    If so, the bike biz espionage is in full swing.
  • 10-04-2007
    Plim
    [SIZE="5"]Here's the definitive answer as to what suspension design is best:[/SIZE]

    [SIZE="4"]The suspension design of the bike I'm currently riding is the best possible design.

    The suspension of your bike sucks if it's different. Really. It sucks. Big time.
    [/SIZE]

    **I have multiple FS bikes with different suspension designs, so you gotta stay on your toes if you want to make sure your suspension doesn't suck. To ensure top performance of your bike, you may want to PM me in the morning to find out which bike I'll ride that day and select your bike to match. I charge $5/day for this service.**

    Now we can stop talking about this subject.
  • 10-04-2007
    frank daleview
    For some reasons, some designs have a hard time making it to the front of the proverbial room. I remember seeing that design last year, I have yet to see one in person, let alone ride one. The reviews I have read were less than flattering--altough the cristicism seemed to focus on the geometry and less on the suspension performance, and this as we all know, largely comes down to a matter of preference.

    Not that they're at all related, but this makes me think of the lesser mentioned Rocky Mountain ETSX.
  • 10-04-2007
    elgatovolador
    What about the Liteville 301 or any of the bikes from Canyon?

    The Germans seem to love them, and their magazines actually do suspension tests quantitatively as opposed to just riding it and saying "it feels good".
  • 10-04-2007
    frank daleview
    Wow! I just watched Felt's interbike tech video--seems like the put some serious thinking into that design. I'm no engineer, but his explanation makes sense. Can anyone here comment on how it performs?
  • 10-04-2007
    Steve from JH
    Quote:

    Originally Posted by iceaxe
    Wow! I just watched Felt's interbike tech video--seems like the put some serious thinking into that design. I'm no engineer, but his explanation makes sense. Can anyone here comment on how it performs?

    Here's some of what I wrote to Derby in a private message. He demoed the Felt Compulsion at Interbike and was not very impressed with it. I think it was not set up right.

    I demoed the Virtue 3 for two days by renting it. I got in two good rides and also spent a lot of time in the garage with the shock removed or deflated, making measurements and tests.

    My ride impression was completely different from yours regarding small bump compliance. I thought the ride excellent. Small bumps simply disappeared. More so (slightly) than on my Ellsworth with a PUSHed RP23 run in the open position (which allows visible bobbing).

    I wasn't as impressed with downhill performance including medium and big bumps. But my impression could very well be skewed by the fact that I couldn't get the fork, a Rock Shox Revelation, to work to my satisfaction and even more by the fact that I'm so used to a Gravity Dropper with instant 4" up or down seat adjustment. I'm used to dropping my saddle now on the slightest downhill that involves coasting and I simply feel insecure and unstable when I have the saddle up high.

    The bike did not bob on smooth pavement in any gear from seated pedaling, unless I threw in a lot of upper body motion. When standing it bobbed pretty much like other bikes. My Ellsworth Id with the platform on the firmest setting (which isn't very firm because of how I had Push tune it) bobs about the same as the Virtue with the platform off. The Virtue had an RP2 with a very firm platform in the on position.

    My bench tests showed a number of interesting things, but they were not scientifically accurate, just eyeball impressions and crude measurements.

    First, the axle path is indeed very close to straight vertical. After an initial slight backward movement, the path straightens out and goes almost exactly straight up.

    When pedalled hard against only the spinning wheel's resistance, the suspension does seem to extend, even in the highest gear. This cannot be explained by the axle path or by the leverage ratio. I'm pretty sure I've figured out the physics and kinematics of this, but haven't posted it because I'm tired of getting abused. By my explanation, you could put a huge chainring on the bike, maybe 70 teeth or more, and combined with the smallest rear cog you'd still develop extension.

    I tried to measure the leverage ratio by comparing the shock travel and wheel travel over the last inch before bottom out. It seemed to be the same as the overall average. This would suggest a level leverage ratio curve rather than a rising one (falling shock rate) as you suggest. But I'm not sure about this.
  • 10-04-2007
    Student Driver
    Would the Felt be for someone that prefers the ride of the Epic or really, really likes firm suspension? I would like to see someone (or even myself) ride it who prefers a particularly active suspension to get his opinion on it. It seems like a design that caters to people who view suspension as a necessary evil rather than something to be embraced (guess where I fall in :)).
  • 10-05-2007
    Steve from JH
    I like a really active suspension, and I rode the Virtue 3, as I reported above.

    I thought it handled the small trail chatter really well and without any rider induced bobbing. I'm not so sure about really choppy trail sections or pure downhill behavior.

    I think the principle of the Equilink could be used to produce as plush a bike as anyone could want.