980g suspension fork anyone?

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  • 980g suspension fork anyone?
  • Premier Icon nixie
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    You don’t, three different stiffness’s available.

    Premier Icon richmars
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    How does one adjust spring rate?

    Thickness (or construction) of the flexure.

    5thElefant
    Member

    The ‘spring’ bit isn’t new, it’s just a flexure. Used all over the place (eg F1 suspension) to give friction free movement. Look in any compliant mechanism text book.

    Or any old horse cart in a museum.

    Premier Icon molgrips
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    Hold on – the two sides aren’t linked, are they? What’s to stop it deflecting left to right besides the axle being clamped in?

    I’d have to ride it, to be honest.

    Premier Icon ir_bandito
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    What’s to stop it deflecting left to right besides the axle being clamped in?

    The axle being clamped in it.
    Its not a massive problem on upside-down forks, like Mavericks, where the two lowers are only joined by the axle. And i guess the flexures are designed to flex vertically and be stiff sideways.

    Bonkers. Probably even quite good in a few situations. Ugly. But I love the fact they’ve got the balls to try something different, regardless of what the armchair (and real) engineers on the forums say.

    Must have missed the 3 different versions, bit of a bugger if you turn into a porker!

    ti_pin_man
    Member

    Reminds me of the Amp forks of old. I’d like to see the reviews, and try before i buy.

    andyl
    Member

    0/10 for assuming that just becasue you typed it, it must be true. I’m sure he read it, just decided it was incorrect. How much damping is there in that carbon? Eff all compared to an actual damper unit. You can see from the video it bobs on small bumps. The tennis racket analogy is incorrect, the carbon racket feels more flexible because it is more flexible. Nothing to do with damping.

    My response was to people implying that there is absolutely no damping. Yes achieving the levels of damping seen in a discrete traditional damper is going to be very hard but there is a hell of a lot you can do with composite materials to increase and control the damping and the levels that can be achieved vary greatly and it does not have to rely on the overall stiffness of the whole structure.

    You need to stop thinking about the whole picture and start thinking on the micro and nano scale at how to dissipate energy at different frequencies. The slow speed damping is going to be the challenge here.

    But until anyone knows what they have done that is not visible and in the press release it’s completely unfair to say there is no damping.

    @molgrips: With regards to flexing from the side you just design the flexibility in directions you want and make it stiffer in the directions you don’t – ie side to side and twisting. Remember with composites you have the effect of fibre orientation to play with as well as geometry.

    Premier Icon ir_bandito
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    Can the springs be removed and replaced with different rates?
    If they can, i guess you don’t need to run all 3 the of the same rate?

    And comparing it to the AMP etc designs, it does has very low unsprung mass, which is a good thing.

    Premier Icon molgrips
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    Of course, but I’d still expect somewhat worse tracking than a traditional fork. But I would like to be surprised 🙂

    It could be a good thing for a TDR race or similar, although I would not choose one until they had been around for a long time to prove reliability.

    cr500dom
    Member

    Thats very neat, I cant see the tracking being a problem if you look at where they have engineered the stiffness.
    The design is only compliant in 1 direction (Z)

    In X it is a classic 4 link only seeing compression and tension loads
    In Y the spring blades are stiff in beam.

    the main Blades (Fork legs) are deeper in section than they are wide, again adding to the fore / aft stiffness, Id be very surprised if they were not greater in torsional stiffness than conventional 29er suspension forks

    The only thing stopping one side compressing more than the other is a 15mm Maxle, and i’m not sure it was designed with that in mind as most fork lowers are held together rigidly.

    The Maverick fork used a custom 24mm one and was still a bit wobbly.

    cr500dom
    Member

    HoratioHufnagel – Member
    The only thing stopping one side compressing more than the other is a 15mm Maxle

    Id suggest you go back and look at it again as a complete system.
    And work out which bits can move and in which direction relative to one another

    Premier Icon thisisnotaspoon
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    The Maverick fork used a custom 24mm one and was still a bit wobbly.

    It also had an insanely light crown made from a hollow piece of metal welded tot he uppers. An example of how weight weenie they were when making it, IIRC the DC version didn’t have a steerer tube, just a crown race on the uppwer and lower crowns!

    toys19
    Member

    Yes achieving the levels of damping seen in a discrete traditional damper is going to be very hard but there is a hell of a lot you can do with composite materials to increase and control the damping and the levels that can be achieved vary greatly and it does not have to rely on the overall stiffness of the whole structure.

    You need to stop thinking about the whole picture and start thinking on the micro and nano scale at how to dissipate energy at different frequencies. The slow speed damping is going to be the challenge here.

    Damping coeffecients:
    Steel 0.0004
    Aluminium 0.0001
    Carbon 0.1
    Typical MTB fork 100’s

    So yes carbon damps at orders of magnitude greater than steel or aluminium, but we are not talking about high frequency (100s Hz) low amplitude (<1mm) vibration here. When this thing deforms we are talking 10’s of hz at most, and many mm. For critical damping (ie to stop it oscillating, bouncing back more than once) it needs a damping ratio of 0.24-0.4 (crit damping is 1, but that makes suspension feel tto stiff) which with a damping coeefcient of 0.1 means that either the spring should be soft (which compared to a normal fork spring, it will be similar, so not) or sprung mass should be very very light. It isn’t.

    But until anyone knows what they have done that is not visible and in the press release it’s completely unfair to say there is no damping.

    PS I can read – Chipp’s article said no damping..

    if only on a technicality – no moving parts.

    Oh, and there’s no compression and rebound damping apart from that inherent in the carbon leaf springs

    Look I’m not dissing the fork, it might work well, but it is a technical fact that will not have any damping like a conventional fork.

    Premier Icon gofasterstripes
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    No thanks.

    argoose
    Member

    No mention of a 26er option?
    Would be interested on the winter bike due to low maintenance plus.

    Premier Icon mick_r
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    Speculation sucks. Coincidentally, visiting Iceland soon – I can feel an email coming on……

    Also got some reference points to compare them with – we were mtb kids of the 90’s, so actually owned Girvin Vector and Quasar linkage forks (still got a slightly broken set of Quasars in the attic)

    Premier Icon chipps
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    Bump! Seems they’re going into production and they’re going to be getting us a test sample when they do. I will be happy to let any of you lot have a go (believers and non-believers) if you come and visit the office some time. Any takers?

    Premier Icon Harry_the_Spider
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    Bring one out on Monday night. You’ll get a full spectrum of fast to fat.

    uwe-r
    Member

    What frame/axl/wheel spec would they need Chipps?

    Premier Icon chipps
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    They’ll be 29er and 15mm I’d have thought. No word on when we might see on yet.

    tazzymtb
    Member

    As a weight weenie 29er rider I’d be well up for checking those out chipps.

    Premier Icon jameso
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    I had a look at these at eurobike, could be quite useful. Can’t quite get over the looks-vs-benefit thing (despite some of other the stuff I own..) but I like the lack of moving parts and I’d be quite keen to try a toned-down ‘CX’ version for bikes that can’t use tyres for any reasonable cush.

    Premier Icon chipps
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    They were also talking earnestly to some fat bike companies… Might be interesting.

Viewing 25 posts - 41 through 65 (of 65 total)

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