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Thread: Modern mountain bike shocks

  1. #1
    Junior Member
    Join Date
    Aug 2016
    Location
    Caracas, Venezuela.
    Posts
    4

    Modern mountain bike shocks

    Hello all!

    My team has been recently looking into alternative damper options. In the past years we have been using the 4 way adjustable Ohlins TTX25 MKII wich are more than 600 $ each, without being able to really take advantage of the 4 way adjustability. Taking this into account and being a small budget team, we have been looking into cheaper options and 2 way adjustable shocks. It seems that in recent years great progress has been made in the mountain bike shocks industry. We´ve looked at a couple of interesting models wich go for less than half the price of the Ohlins, such as the
    RockShox Kage RC. On the other hand we've read relatively old posts talking about the problems with mountain bike shocks, such as not consistent curves between different shocks and being overdamped for FSAE applicaitons.

    We'd love to hear from your experiences with such modern MTB shocks.

    Cheers,

    Rodrigo
    Rodrigo Luengo

    Universidad Simón Bolivar FSAE-USB
    2015-2016 Brakes/suspension
    2016-2017 Suspension
    2017-2018 Suspension/Management
    @fsaeusb

  2. #2
    Senior Member
    Join Date
    Mar 2008
    Location
    Brighton, MI
    Posts
    598

    Gimme a brake.

    Brake pads. Friction is your friend. Looks good on the cost report. Easy to develop using an old lawn tractor as a dyno. Just add some bumps.

  3. #3
    Zurich had some success with (customized) DT Swiss MTB dampers.
    We started using them in 2012 and they are great, super lightweight and very cheap.

    I would suggest to reach out to the current team to give you some inputs. They are now running adaptive ones with some crazy magneto-fluids but still they are running those DT Swiss parts.

    Interestingly, no other (top) team seemed to be happy with MTB dampers, so maybe the customization is an issue.
    -------------------------------------------
    Alumnus
    AMZ Racing
    ETH Zürich

    2010-2011: Suspension
    2012: Aerodynamics
    2013: Technical Lead

    2014: FSA Engineering Design Judge

  4. #4
    Julian,
    If you don't mind telling, is AMZ now running both hydraulic interconnected and magnetic controlled damping?
    thanks
    Tim

  5. #5
    Hi Tim,

    yes, that is correct. They run an interconnected hydraulic suspension and have the dampers for the different modes magnetically controlled - sitting on the back of the car on top of the diffuser.

    Best
    Julian
    -------------------------------------------
    Alumnus
    AMZ Racing
    ETH Zürich

    2010-2011: Suspension
    2012: Aerodynamics
    2013: Technical Lead

    2014: FSA Engineering Design Judge

  6. #6
    A damper is a damper. Do you have access to a shock dyno? If yes, choose/draw your desired damping curves, pick a damper body that suits your application, revalve until happy.

  7. #7
    Junior Member
    Join Date
    Aug 2016
    Location
    Caracas, Venezuela.
    Posts
    4
    Tim, AMZ just posted this video of their suspension system. It doesn't show that much, but it has an explanation of the system and it's quite interesting nonetheles

    https://m.facebook.com/story.php?sto...id=92330576106

    On the other hand, thank you to everyone who took the time to reply. I really appreciate it. Most likely we'll go with the Fox shocks or get the maintenance kit for the Ohlins (They were leaking quite a lot through the piston rod). We do have a vertical self-made shock Dyno, so we should be able to get an idea of how well they're functioning.

    Best regards,

    Rodrigo
    Last edited by luengorod; 07-11-2017 at 12:12 AM.
    Rodrigo Luengo

    Universidad Simón Bolivar FSAE-USB
    2015-2016 Brakes/suspension
    2016-2017 Suspension
    2017-2018 Suspension/Management
    @fsaeusb

  8. #8
    https://www.facebook.com/amzracing/v...5045552431107/

    To view without a facebook login, go to the link, click 'Not Now' below the login options, then click the view full screen icon on the lower right of the video.
    Jay Swift
    Combustion Powertrain
    Global Formula Racing 2013-2014

  9. #9
    Hi Rodrigo,

    getting back to the original topic:
    I guess you were referring to some old posts by myself talking about hose problems.
    The reasons for these posts are still very much there for mtb shocks, especially overdamping. Bike shocks are installed at a motion ration of somewhere around 3:1 and there is only a single shock supporting ~70% of the vehicle/rider weight.
    In an FSAE car, you have four shocks installed at 1:1 usually, supporting a around 270kg car and driver. So if you do the math, you'll realise that bike shocks run significantly heavier spring stiffnesses and due to that, their "base tuning" on the damper side is a lot stronger and the adjustment range is not enough to compensate for that.

    So, unless you have all the necessary know-how and equipment (usually the expansion chambers are nitrogen filled...) for rebuilding and revalving a shock, bike shocks are pretty useless in an FSAE car.
    Lutz Dobrowohl
    2008-2011
    Raceyard Kiel

    Now: Scruitineer, Design Judge, application engineer @Altair engineering

    Whatever you do, do it hard!

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