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Suspension for bicycle

  1. Jan 2, 2017 #1
    Hello,
    I need to know what is the best type of susension system for bicycles.And also rating of a motor to drive a 5 kg load.I am still studying B E .Please it is urgent. Thaks for helping.
     
    Last edited by a moderator: Jan 2, 2017
  2. jcsd
  3. Jan 2, 2017 #2

    BvU

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    Hello Hareesh, :welcome:

    Best type of suspension for what bicycle ? Racer bikes have no suspension; mountain bikes have front and rear, my commuter bike has front only (and I don't like it).

    A BE student should understand a specification like "drive a 5 kg load" is inadequate. Does it have to lift 5 kg in a month ? Then a toy motor is good enough.
     
  4. Jan 3, 2017 #3

    For running a flywheel.I am sorry it is a 15 kg flywheel.The suspension should withstand an overall of 90-100 kg.So can you prefer a cheap one, please?
     
  5. Jan 3, 2017 #4

    BvU

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    I'm very weak at telepathy. What's this about ? Running a 15 kg flywheel with a "5 kg load" motor, designing suspension for a racing bike that carries 5kg load, a 15 kg flywheel plus a motor and perhaps also a car battery ?
    :smile:
     
  6. Jan 5, 2017 #5
    Hareesh your questions are not clear ,I think there are two things which need two answers
     
  7. Jan 7, 2017 #6
    No its a 15 kg flywheel,not a 5 kg load.The cycle carries the flywheel, motor and the driver.
     
  8. Jan 7, 2017 #7

    berkeman

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    Why not just use standard mountain bike suspension components? They come in a wide range of prices...

    http://www.davescheapbikes.com/wp-content/uploads/2013/05/cheap-dual-suspension-mountain-bikes.png
    cheap-dual-suspension-mountain-bikes.png
     
  9. Jan 8, 2017 #8

    BvU

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    Perhaps this is too late then. But you started a potentially interesting thread. Maybe next time it'll go better if you are a bit more complete in describing what you are after. My post #4 was intended to be slightly ironic -- sorry, I can't help it :rolleyes:.

    But even after a week it isn't clear to me what kind of bike this is for, whether you need front and rear or only one of the two and, especially: why you would want a suspension at all. Comfort ? Performance ? Or because it was a requirement in the design assignment you were given ?

    The PF homework fora all have a template starting with 1. The problem statement, all variables and given/known data and a full statement would have been very helpful here !
     
  10. Jan 8, 2017 #9

    CWatters

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    Just about any size motor will turn a flywheel at a constant speed. What matters is how fast it must go and how fast it must reach that speed. You also need to know the moment of inertia and the operating voltage.
     
  11. Jan 8, 2017 #10

    berkeman

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    It would seem that the flywheel should be a special type if you are going to mount it on a bicycle. A 15kg flywheel on a light bicycle can do some scary things if you don't use a special type of flywheel. Can you comment on that @Hareesh Venkatraan?
     
  12. Jan 20, 2017 #11
    After design calculations I found the actual weight of the flywheel to be fitted as 7 kg.It is an aluminium flywheel.So I need a motor to rotate the flywheel and am thinking about powering the motor by solar energy.
     
  13. Jan 21, 2017 #12
    Still unclear. As mentioned above, the faster you want to accelerate the flywheel then the more force and power you need. If the flywheel delivers any energy to the bicycle then that has to be known, and some recovery rate must be specified. If the bike is going to ride on city streets then no suspension is needed. If it's going to ride along railroad ties then a very compliant suspension is needed.

    Try to fill in the unknowns and the community will try to help.
     
  14. Jan 21, 2017 #13

    BvU

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    What design calculations ? Do you understand it still isn't clear what it is you are trying to do ? You start with a question about suspension and end up with the outcome of a design calculation for a flywheel. Please be complete. Is there a problem statement ?

    You tell us it's an aluminum flywheel. Why ? Because aluminum is lighter than iron :smile: ?
     
  15. Jan 21, 2017 #14

    berkeman

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    Did you understand my comment below? It's pretty important...
     
  16. Jan 21, 2017 #15
    Can't understand what is "special". Please can you elaborate???
     
  17. Jan 21, 2017 #16
    Do you know about the roads in India?I am designing for these roads
     
  18. Jan 21, 2017 #17
    Its density is less and occupies less weight fo given volume than iron or steel.

    I need to design a bicycle with a flywheel and I also decided to put a suspension in it.
     
  19. Jan 22, 2017 #18

    CWatters

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    A flywheel made from expanded polystyrene (EPS) would occupy even less weight for a given volume than aluminum, iron or steel :-)

    Is the flywheel for energy storage or stability or ?

    If it's for energy storage then how much energy do you want it to store? That dictates how fast it must spin and it's moment of inertia. The moment of inertia effects it's weight and size. If the size is constrained then the heavier the flywheel the more energy it can store. So why would you want to use an aluminium flywheel?
     
  20. Jan 22, 2017 #19
    It is cost effective and also occupies less volume .
    It is used for storage purose.
     
  21. Jan 22, 2017 #20

    CWatters

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    An aluminium flywheel would require MORE volume than an iron or steel flywheel.
     
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