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  1. #1
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    Funny Front Ends

    I think this is pretty neat.

    https://www.pinkbike.com/news/struct...tler-2017.html

    It's all been done in motorcycle world. Been done well in the bike world (PRST1). Here's a modern-trends-and-components take on the subject.
    Disclaimer: I run Regular Cycles (as of 2016). As a profiteer of the bicycle industry, I am not to be taken very seriously.

  2. #2
    pvd
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    Linkage front ends don't work.

  3. #3
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    Quote Originally Posted by pvd View Post
    Linkage front ends don't work.


    yes they don't work. on bikes. in real world use and bike production, nope.

    linkage front ends do not work in any past or present bicycle configurations as
    weight penalty and oddball looks make an unpopular platform.

    where they have worked are in the motorized vehicle world where heavy components are not an issue. big bearings and structure is made to make it work.
    "Put your seatbelt back on or get out and sit in the middle of that circle of death." - Johnny Scoot

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    Quote Originally Posted by pvd View Post
    Linkage front ends don't work.

    Can't work because they're a bad idea or don't work due to weight/stiffness/complexity constraints?

  5. #5
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    Quote Originally Posted by PhillipJ View Post
    Can't work because they're a bad idea or don't work due to weight/stiffness/complexity constraints?
    it's a good idea but cannot be executed on a pedal bike

    20 years of different ideas coming to market and failing, have proven it

    either it's beef (and heavy)
    or light (and breaks early in the lifecycle)
    or...no one wants one, we are happy with linear telescopic forks
    "Put your seatbelt back on or get out and sit in the middle of that circle of death." - Johnny Scoot

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    Wow- Lots of experts who have built nothing (except PVD) with strong opinions. The internet
    is awesome for that, go figure.

    Hang back and see. Could be the next wave of new bike tech. I frankly like it and think CF construction is now scaling up in such a way that the previous drawbacks can be properly engineered out.

    I am not a fan of slider forks for a lot of sound engineering reasons.
    Last edited by chasejj; 08-16-2017 at 05:19 PM.

  7. #7
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    Quote Originally Posted by 127.0.0.1 View Post
    (snipped) oddball looks make an unpopular platform.
    Fair observation. However, my business approach is based on niches. I do not need popularity in order to function.

    My dog in the fight is that I have an extreme dislike of having to put an entire bike chassis out of use temporarily because of fork maintenance. I'd rather just have external spring/damper as with rear suspension. In this way, I would have a "B" shock that I stick on the bike while the A shock is being serviced. Much more affordable / fast / easy to just swap out a small component using a pair of bolted eyelets.

    PVD: 10/10, unhelpful, would gloss over again
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  8. #8
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    Quote Originally Posted by 127.0.0.1 View Post
    ...or...no one wants one, we are happy with linear telescopic forks
    Wrong. I like telescopic forks so little that I'd sooner ride rigid.

    Telescopic forks are an over priced kludge. ie they were never a good idea and to make them work properly is expensive.

    The problem with linkage forks on bicycles is that the market will not accept an unconventional look so linkage fork design has been compromised to look more acceptable.

    I have a small collection of linkage forks, and their main failings are too short links affecting the suspension path thus radically altering the steering geometry, and the lack of availability of decent purpose-built shocks when they were made.

    The Whyte PRST almost got it right.
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  9. #9
    pvd
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    Every bike geek in the past 100 years has tried to make linkage front ends work. It's the dream. They work so well on paper and in short run experiments.

    The problem is that all of the links quickly eat up the bearings and create slop. Sloppy floppy front ends are terrifying. Far worse than a stiff telescope. Nobody is looking for a front end that needs a complete teardown every 5 hours just to stay safe.

    Like I keep saying, telescoping front ends are the absolute worst way of doing it and, so far, the best we've got.

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    Peter- Lets think this over. The link arms and respective bearings are same tech as current rear suspension designs. There is not an uproar about bearing service life , I'm aware of. The scissor link is only taking steering loads and that could be the unknown factor . Other than the extra links that can add up if there is excessive play and cause some funny steering. I'm not seeing how this is a whole lot different than what we have in back just played out in front.

  11. #11
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    Quote Originally Posted by pvd View Post
    ...The problem is that all of the links quickly eat up the bearings and create slop. Sloppy floppy front ends are terrifying. Far worse than a stiff telescope. Nobody is looking for a front end that needs a complete teardown every 5 hours just to stay safe....
    That's just sloppy manufacture and design.

    I've ridden tens of thousands of miles on various girder fork British motorbikes and had no problem. They used bronze bushes which were quite small and would work just as well on a bicycle. It's the appropriate bearing for a hinge. Of course they did have grease nipples to keep them properly lubed.

    Also you don't need as much suspension movement because you don't lose much travel to brake dive if your design is right.

    I don't disagree with your assertions because really it's just highlighting how badly linkage forks for bicycles have been made in the past. However I do believe that a properly designed and built fork would work well.
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  12. #12
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    People are weightweenies, mostly, for better or (mostly) worse. If you're going to use decent bearings and make everything stiff enough (remember, it's a LOT of pivots) you end up with a tank of a fork. Or you do bushings like the AMP/et al and you end up with something that rides great for about 1 day before it's terrifying.

    That said, I'd love to ride it (and I once spent some time working on building a linkage fork of my own, a project I sadly abandoned due to having kids and a lot less free time).

    -Walt

  13. #13
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    Quote Originally Posted by chasejj View Post
    Peter- Lets think this over. The link arms and respective bearings are same tech as current rear suspension designs. There is not an uproar about bearing service life , I'm aware of. The scissor link is only taking steering loads and that could be the unknown factor . Other than the extra links that can add up if there is excessive play and cause some funny steering. I'm not seeing how this is a whole lot different than what we have in back just played out in front.
    I'll ride a bike with a somewhat sloppy back end, no problem. the front though, the part I am driving into corners, has to be real precise. and light enough I can hurk it up over something square edged.
    "Put your seatbelt back on or get out and sit in the middle of that circle of death." - Johnny Scoot

  14. #14
    pvd
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    You guys can argue it all you like but it hasn't happened because it doesn't work...yet. It may one day but re-hashing old stuff isn't going to do it.

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    Quote Originally Posted by pvd View Post
    You guys can argue it all you like but it hasn't happened because it doesn't work...yet. It may one day but re-hashing old stuff isn't going to do it.
    Up until recently mtb springs/dampers have lagged far far behind what's available in other applications. There's no incentive to explore financially riskier linkage forks when one could make a nominal improvement to a telescoping fork and enjoy a year of predictable sales. Going forward that well will be drying up.
    "Things that are complex are not useful, Things that are useful are simple."
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  16. #16
    pvd
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    I'm sure the folks in MotoGP would argue that.

  17. #17
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    Quote Originally Posted by pvd View Post
    I'm sure the folks in MotoGP would argue that.
    I've found MotoGP bikes and SuperBikes are pretty crap on technical sections and drops, although my old BMW wasn't too bad.
    When a bicycle does 200+ mph, I'll take their advice.
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  18. #18
    pvd
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    Well, they get to spend a few million dollars on each bike and pilot them with the best riders in the world. They have just one goal, to win. They will use any technology that will help them....and they use telescoping forks.

    Even F-35 Lightnings use telescoping suspension...and they cost about $120M each.

    Believe me, I'd love to see telescopes die, but nothing has been able to yet.

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    How strange. Telescope forks are amazing. A few fixed bushings support 2 tubes with minimal seals and just a few ml of oil. It's silly easy and cheap to make a reliable one, and still very easy to damp one well. They're so ridiculously good now that absolutely insane riding is possible. People are the shortcomings, not the equipment.

    I don't want that to change. Definitely not interested.

  20. #20
    pvd
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    The problems with telescopes are numerous and fact.

  21. #21
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    Quote Originally Posted by One Pivot View Post
    ...Telescope forks are amazing. A few fixed bushings support 2 tubes with minimal seals and just a few ml of oil. It's silly easy and cheap to make a reliable one, and still very easy to damp one well. They're so ridiculously good now that absolutely insane riding is possible. ...
    I agree with that, but there's a but...

    It was their cheapness to manufacture that lead to their popularity, but by the time you have them working properly they are a ridiculously expensive solution that requires major compromises with the bike geometry and a high level of skill to handle those compromises.

    To keep them functioning properly they require expensive maintenance.

    A highly developed kludge.
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    Lots of complaints and no solutions. Is this how you can convince yourself that you're progressive, while never actually making any progress?

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    Quote Originally Posted by pvd View Post
    Well, they get to spend a few million dollars on each bike and pilot them with the best riders in the world. They have just one goal, to win. They will use any technology that will help them....and they use telescoping forks.

    Even F-35 Lightnings use telescoping suspension...and they cost about $120M each.

    Believe me, I'd love to see telescopes die, but nothing has been able to yet.
    Funny you mention the F-35. Trailing link landing gear have a reputation for making a pilot look good on landing and they're a linkage design. Just playing devil's advocate here... ;-)

    When you talk about linkage front ends, are you referring to bikes where the linkage is integrated into the frame, like the Whyte PRST-1 , forks like the Girvin Vector, or both?

  24. #24
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    Quote Originally Posted by pvd View Post
    The problems with telescopes are numerous and fact.
    They're not perfect, but they're extremely good. Once you move past theoretical analysis, they're silly good.


    What are forks not doing for you guys anyway? We're to the point now where you can ride down nearly anything without breaking your fork or losing control, and we're just left nitpicking how much small bump we can erase. I don't think gear that removes the necessity of skill is an improvement.

    Its not a fact anyway, it's subjective since it's a hobby. That's like saying rigid forks have factual downsides.

    I just serviced my fork for probably the 6th time this season (doing internal swaps and playing with it). I think I may be up to a dollar in oil used.

  25. #25
    pvd
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    Sliding friction is extremember in telescopes. Worse on modern bikes. The structure is shitty too, although BMW has impriver that on heavy bikes.

    I've been at all of this for a while. Telescopes are very bad and things aren't looking good for options.

  26. #26
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    Quote Originally Posted by pvd View Post
    Sliding friction is extremember in telescopes. Worse on modern bikes. The structure is shitty too, although BMW has impriver that on heavy bikes.

    I've been at all of this for a while. Telescopes are very bad and things aren't looking good for options.
    Way back when I was heavily into motorbikes (1970s) a mate & I tried to build a telescopic type fork using rollers on the moving part (ie what we call the sliders). It was an extremely crude construction (we were just backyard bodgers) but it certainly was free moving, so the problem then became one purely of damping. The general idea was that the stanchions would not need to be at the same angle as the steering head so we could vary the geometry through the stroke. Think a long plunger suspension with rolling sliders and not necessarily on a straight tube (ours was straight).

    It never came to much because we both got posted off to different places shortly after, and the idea wasn't original. If I remember right it was based on something I read from one of Phil Irving's books.
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    Tried it in the 90s and in no particular hurry to go back. Really persevered with UK made Quasar forks but they continually developed play (constant loose headset feeling) and grease from the bushes and ports went everywhere. The only thing they were superior for was supple ride on small stuff like bumpy grass.

    My wife was sponsored to ride xc with late model Girvin forks (Noleen shocks). Don't think we had any major issues for the season and the non greaseport bushes worked better at the cost of some friction.

    The one fork I'd like to have seen developed was the USE Sub.

    Car linkage suspension gets round the pivot wear issues using bonded steel / rubber bushes but no way I can see those working in a bike situation where we want stiffness and precision in all other directions.

  28. #28
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    Quote Originally Posted by mickuk View Post
    ...Car linkage suspension gets round the pivot wear issues using bonded steel / rubber bushes but no way I can see those working in a bike situation where we want stiffness and precision in all other directions.
    Greeves motorbikes used that in their linkage forks. It's a long time since I've ridden one but I don't remember any slop and it had a few miles on it.

    Something like this.




    I have a Quasar fork in my collection of linkage forks, and can see what you mean.
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    So, what happens when you reduce the sliding friction? Has anybody here ridden a Lefty?

    The problems with telescoping forks are the problems that plague all of MTB suspension: spring and damping characteristics have to be 'generalist' to accommodate the constant movement and oscillation of the rider/motor. We then judge the effectiveness of the suspension about either how it fails to be a 'specialist' (even after you've agreed to compromise for other characteristics), or how it 'generally' fails to be excellent at all things. I would agree that telescoping forks work pretty dang good, considering all we ask of it. Could it be better? Of course. We're not suspended by leaf-springs while riding wooden wheels and being drawn by a horse. Progress has been good in that regard.

    Are linkage front-suspensions the solution? I don't know. But at the very least, the design exercise is fruitful to determine what benefits may result from the different wheel paths-of-travel, kinematics, damping and spring characteristics that can be implemented with a linkage. If there exists a marked benefit, engineers can then figure out how to achieve those characteristics in a design that would then be reliable, lightweight, affordable, etc.

    On a related note, if you haven't read PVD's blog on 'forward geometry' (http://www.peterverdone.com/forward-geometry/), I'd recommend it. One characteristic I think is relevant to the progress of front suspension is how 'forward geometry' constrains the fore/aft movement of the rider/COM. Coming full circle back to reduced stiction and the Lefty, what benefit is increased small-bump sensitivity when a shift in your COM pushes the fork deeper into its spring/damping curve? How will suspension remain active when you're forced to lock the damn thing out every time you pedal out of the saddle? IMO, 'Forward geometry' may further help front suspension development by allowing the fork to be tuned around a more narrow range associated with a constrained COM.

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    How did I forget about Greeves? I read a book on their history just a few months ago! Think they began using the rubber in torsion for the suspension spring and friction damping plates. Then gradually added hydraulic dampers and (?) coil springs as the years went by. Suppose using it for the spring means they can use a very stiff compound. As well as UK trials, they were very popular for desert racing in US.

    Will have to discuss more at SSUK - have you made that bike yet? A photo of mine is on the current stw thread....

  31. #31
    pvd
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    Lefty forks aren't very good. Mostly a marketing gimmick. Any contamination and the system turns to garbage. It's also very expensive to make work well when it does. Very few professional riders will use them unless forced to by sponsorships.

    Folks, (ie this Greeves nonsense) make sure not to confuse something that was produced with something that should have been produced. Plenty of horrible contraptions have been made in history. That isn't a testament to their validity.

  32. #32
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    Quote Originally Posted by pvd View Post
    ...Folks, (ie this Greeves nonsense) make sure not to confuse something that was produced with something that should have been produced. Plenty of horrible contraptions have been made in history. That isn't a testament to their validity.
    You may or may not be right there.

    But it seems to me bicycle forks are probably not going to be used for any higher speeds than those forks were used for. Their action was much nicer than a telescopic of the time. Their limitation was that they would have needed considerable alteration for the demand for longer travel as the sport tended towards more spectacular jumps on purpose built courses rather than actual cross country use. That is why they were replaced, not because of any inherent defect.

    It's the usual case with bicycles, the specification demands of the superfit few who are capable of riding fast become the fashionable product for the mass market who aren't, being more mass than fit but wanting to look the part. Racing overspecialises the breed IMO.

    Mick, I've looked at your bike and think you've taken overspecialisation to the other extreme.
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  33. #33
    pvd
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    Quote Originally Posted by Velobike View Post
    That is why they were replaced, not because of any inherent defect.
    They were not adopted because they didn't work. Some slow guy riding lame trail may feel like a fork is great over 1/4 season that didn't involve any mud. Put a real rider on the thing over a muddy winter somewhere and the things are useless.

    Travel has never plaid a roll in why they haven't been adopted at any given time as travel change has been very very slow.

  34. #34
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    Quote Originally Posted by pvd View Post
    Lefty forks aren't very good. Mostly a marketing gimmick. Any contamination and the system turns to garbage. It's also very expensive to make work well when it does. Very few professional riders will use them unless forced to by sponsorships.
    Dissagree. not to get into a different argument but anyone who has said lefty is crap has never had one. I service mine less than my friends and ride twice as much. much smoother and performs better than their fox or rockshox. like anything it is called taking care of what you own.

    I like the idea of this bike, however I feel I might loose a testicle in the linkage. But just because something is unconventional does not mean a failure of a design. If it wasnt for new ideas we would still be riding retrofitted road bikes.
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  35. #35
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    ...and there we go.

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    Quote Originally Posted by pvd View Post
    They were not adopted because they didn't work. Some slow guy riding lame trail may feel like a fork is great over 1/4 season that didn't involve any mud. Put a real rider on the thing over a muddy winter somewhere and the things are useless....
    Mud? The UK is mud central and Greeves made mudpluggers par excellence.

    All I know is their forks worked perfectly well when I rode them, and were better than telescopic forks of the time for offroad use.

    But really we shouldn't be arguing over Greeves - they were motorbikes after all. I only mentioned them because of the use of bonded rubber for the pivots.

    If we want an example of a bicycle with bonded rubber, we could look at the early Moultons where that was used in conjunction with a pivot, but at the rear. I don't recall any slack occurring in them.

    I have a couple 50 year old versions in the shed so I'll pull them out in the morning and check. That style might work if it was done like a BMW leading link fork although you'd need a long front centre to ensure no interference from feet.

    I'm not sure what you call a lame trail or a real rider. To me a lame trail is a built course with artificial features. A real rider to me is someone who does the Tour Divide or the likes of the expeditions the Alaskan and Australian riders do, so we probably have different perspectives.
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  37. #37
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    I think that we've established that you aren't a reference for viable front end configurations..

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    Quote Originally Posted by pvd View Post
    I think that we've established that you aren't a reference for viable front end configurations..
    Obviously not for your riding, but mine is equally valid.

    However I thought we were discussing your comment "The problem is that all of the links quickly eat up the bearings and create slop" hence to diversion into forks that didn't have that problem.

    BTW the 50 year old Moultons I have don't have slop. That of course is a rear fork, but the principle of using bonded rubber could be used for a front.

    However it appears to be getting personal, so I'm out of the discussion now.
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  39. #39
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    I wonder, what is the state of the art with non-frictional / flexural pivots? What I see are short angular capacity. I am not enthused about using the Lauf fork design, I'm not a big fan of putting fiber under a tension/bending load while also exposed to physical striking from rocks / plant life.

    I guess a tuneable Lauf is what I'm after, bearing-less with an external shock.

    Failing that, I guess I'd rather just choose an arrangement of bearings that are expensive to replace so long as the service intervals are quite long.

    "They don't work" is too aggressive a simplification to me. I don't buy it. Maybe they don't work for 99% of the population. That's acceptable. Does it have to be that the 99% solution makes up 100% of the product market?

    People are still buying vinyl records. I am pretty sure I will be able to sell their bicycle-consumer-analogues some weird bike parts without fleecing them via an inferior product.
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  40. #40
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    deleteme

    but I'd like to try it

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    Quote Originally Posted by pvd View Post
    I think that we've established that you aren't a reference for viable front end configurations..
    While I respect your viewpoints and believe you have some good knowledge on this subject, I've also seen enough from Velobike and his experience with a wide range of bicycles of all types to believe he has insight as well. And I had to laugh when you mentioned the mud; from his postings it sounds like he rides more in mud than just about anyone.

    Anyway, not trying to take sides here, just saying it's a huge area to explore and just because an idea failed at one (or multiple) point(s), doesn't mean the basic idea is a complete write off with no solutions to deal with the issues.
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    Quote Originally Posted by Drew Diller View Post
    I wonder, what is the state of the art with non-frictional / flexural pivots? What I see are short angular capacity.
    Scott, Felt, and Giant sell bikes with rear triangles that flex to eliminate one of the pivots in the rear suspension. Felt's is CF and saves weight, Giant's is aluminum and saves money. "Rigid" forks flex a lot, too.

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    Telescopic forks are not that great because there is usually a considerable sideforce on the sliders causing friction. Under braking this changes so then your damping is greatly affected. The steering geometry changes aren't that great either. However they have been around a long time, and they can be made to work pretty well, just like a Porsche 911.
    Put the sliders high up in the headtube, and stiction becomes an even bigger problem with the big lever, the needle bearings are needed because with normal bushings the fork would lock solid.

    If you only have pivots the friction stays the same, you can dial in some interesting wheelpaths (trailing over bumps, anti dive etc). Packaging is more difficult, and all those bushings, bearings etc cost real money. For a manufacturer it is much easier to buy a load of forks, and specify a different one the next model year.

    The Moulton NS uses rubber flexitors, but as the late Dr Moulton put it, he wasn't into landing gear for aircraft, he designed suspension for the road.

  44. #44
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    Front linkage designs

    Some great ideas and discussion in this thread! It’s wonderful to see the ideas put forth by fellow tech-savvy riders, engineers, and fabricators. Thanks for this opportunity to discuss one of my favourite topics.

    Rather than address every single point that's been raised or vehemently defend the Structure design, I’ll just address a few recurring themes and raise some ideas to consider.

    Pivot Slop

    Well-executed rear suspension linkages can be extremely stiff, free of slop, and durable. The front is under less load and the most stressed pivots can have wider spacing, so it seems plausible a front linkage can be even stiffer and tighter than the rear. Also, we're not comparing a linkage front to a rigid front, but to a sliding system that moves on bushings, has modest overlap between sliding elements, has inherently longer cantilevered elements, and pushes contamination into the system as it slides; if any system sounds prone to slop, perhaps it's not the linkage system.

    Weight

    The most overrated parameter in cycling*. I use titanium and aluminum bolts and I even weigh my clothes because weight does matter, but I still think it's a minor – almost trivial – variable. The upper limit of the effect of extra weight on climbing speed is proportional to total system weight (you + bike + gear). Two pounds** is about one percent; factor in air resistance and friction – especially the losses at the rubber/dirt interface (different from rolling resistance, as typically measured in lab experiments) – and those two pounds may slow you down half a percent, or a few seconds up an entire mountain. But if those two pounds create a more capable bike, I believe you'll gain far more time on the flats and descents than you lost on the climb – and you'll certainly have more fun! I contend that design choices in the bike world often satisfy consumer demand for light products, with the engineers knowing the decision will make a worse bike – certainly a worse experience – yet will generate more revenue.

    * Sprung:unsprung mass is an entirely different conversation.
    ** 2 lb is just a convenient number; our bike does not weigh two pounds extra!

    Prior Front Linkage Bikes/Forks

    Some have had good elements and some have been … “learning opportunities”. The same is true for telescoping forks – and every design. The existence of sub-optimal designs does not inherently mean any specific configuration – let alone the entire concept – is inferior. Linkages provide so much design freedom that two designs, even of the same configuration, can be more different from one another than any two telescoping forks.

    [continued in next post]

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    Front linkage designs (continued)

    Scarcity of Front Linkages in Motorcycle Racing

    Every application must balance a unique set of pros and cons. The balance is different for every application.

    First, consider brake dive: Motorcycles (including rider) have a much lower centre of mass than mountain bikes and a slightly steeper head angle, resulting in less than half the brake dive inclination of a mountain bike (if my best guess at center of mass location is correct). MotoGP bikes have less suspension stroke, reducing the consequences of dive force. There can also be considerable air pressure on the rider’s chest, further reducing dive. Finally, a track is a more uniform surface than a trail, so MotoGP riders can brake aggressively, with a smaller margin of over-the-bars safety, relative to a mountain biker. This suggests mountain biking has a greater need for systems that control dive and actively manage dynamic geometry.

    Second, consider space constraints. If a motorcycle is reconfigured to afford space for a front linkage, the sacrifices may be more detrimental than the fork is beneficial. The fork could be superior, but the complete system may not be. Mountain bikes are less constrained by space within the frame.

    Existence of Telescoping Suspension Systems in Other Applications

    An example of aircraft landing gear was cited earlier. In the case of a fighter jet, the quality of the suspension is of trivial importance, relative to weight and compact dimensions. The priorities of this application, compared to those of mountain biking, are as different as the designs of each user’s helmets. If the comparison was valid, it would suggest we need oxygen masks on our bike helmets. It would also suggest Formula 1 cars with multi-link suspension systems featuring carefully calculated pitch centers are misguided and should use telescoping suspension.

    Scope of Application

    If front linkage systems are superior, why don’t they feature on all bikes? Let’s flip this question and look at rear suspension: most high-end rear suspension systems are multi-links with air springs, yet the low-end market (including department-store bikes) is dominated by single-pivots and coil springs. Manufacturing cost is a significant factor. The SCW 1 costs several times as much to make as our high-end competitors’ frames (some of that is due to economies of scale, but multi-links are unlikely to ever be cheaper). Just as single-pivot rear designs dominate the low end of the price spectrum and multi-links dominate the high end, a similar split could make sense for front designs. Structure has no expectations of stealing market share from the industry giants; we’re content to occupy the highest performance niche within the high performance market, much like an exotic car manufacturer.

    Weakest Link is the Rider

    Rider skill will always the be the greatest limitation to performance. The argument that existing designs are sufficient if the rider is the weakest link is equally valid to oppose all innovation and development, not only front linkage designs. People opposed to innovation and development are not our target demographic.


    If front linkages were the norm, with over a quarter-century of refinement, and someone introduced the telescoping fork, how would you receive it?

  46. #46
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    TL;DR - they still stuck more than telescoping forks. As of right now.

    -Walt

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    Linkage forks strike again!

    https://www.pinkbike.com/news/scurra...bike-2017.html


    Modern motorcycles have also weighed the merits of linkage design, whether it be BMW's k1200r, or Honda's '18 Goldwing:
    https://www.topspeed.com/motorcycles...-ar177216.html
    Certainly its not just an aesthetic element that attracts buyers willing to drop $30k on a touring bike.

  48. #48
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    Quote Originally Posted by VegasSingleSpeed View Post
    Linkage forks strike again!

    https://www.pinkbike.com/news/scurra...bike-2017.html


    Modern motorcycles have also weighed the merits of linkage design, whether it be BMW's k1200r, or Honda's '18 Goldwing:
    https://www.topspeed.com/motorcycles...-ar177216.html
    Certainly its not just an aesthetic element that attracts buyers willing to drop $30k on a touring bike.
    Scurra is taking a different approach to dynamic geometry than Structure, which the animated .gif on their website hints at, for those who are curious. Naturally, I like the Structure approach - if I didn't, I would've changed our design! - but I'm happy to see another company trying to improve on the basic design of mountain bikes. Everyone at Structure thanks them for increasing awareness of front linkage designs and we wish them success!

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    Honda still owns the rights to this and may bring it back. It won races in early 80's and then was shelved, but not for performance reasons

    Funny Front Ends-082015-top-10-honda-museum-08-prototype-suspension.jpg

  50. #50
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    Quote Originally Posted by chasejj View Post
    Wow- Lots of experts who have built nothing (except PVD) with strong opinions. The internet
    is awesome for that, go figure.

    Hang back and see. Could be the next wave of new bike tech. I frankly like it and think CF construction is now scaling up in such a way that the previous drawbacks can be properly engineered out.

    I am not a fan of slider forks for a lot of sound engineering reasons.
    Agreed 100% opinions are like *ssholes. Everyone has one and the only that that comes out of them is sh!t. Ain't the Internet grand?
    A garage full of steel frames means happiness.

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