old speed bike

Discussion in 'Introduce Yourself' started by miguelitro, Nov 27, 2010.

  1. miguelitro

    miguelitro New Member

    i,m miguelitro from spain.
    my old speed bike is near to return fastest.
    i use a pocket bike engine and i need only work in the sprokets , because the 700 wheel have 2 meters and it,s so longer, i need down half.
    soon i,ll publish photos

  2. 5-7HEAVEN

    5-7HEAVEN Guest

    Last edited by a moderator: Nov 27, 2010
  3. miguelitro

    miguelitro New Member

    hello 5 7 heaven
    will try to do it in two steps. intermediate step so I can use for making a dynamo strength:eek:
    'll have to do several tests in the development but that is the least of worries me.
    the problem is finding the location of gears, crown and chain.

  4. 5-7HEAVEN

    5-7HEAVEN Guest

    Pocketbike Parts!

    JMO, pocketbike parts are cheap and readily available, thru www.ebay.com or many pocketbike websites. :idea:

    Freeway mechanisms with left-hand and right-hand threads can set up your engine drive thru the bike's cassette or left-side independently. These parts will work with the SBP shift kit too.:detective:
  5. BiMoPed

    BiMoPed New Member

    Hi 5-7HEAVEN
    Do you have a link where to buy 6 spline sprockets for the 5 to 1
    transmission that use 415 chain? or other 1/2" pitch chain?

    Looking for 10, 11, 12 , 13 teeth
  6. ibdennyak

    ibdennyak Guest

    I believe Dax has 10 and 11 tooth, and Dave Staton has even more. They use the 410 chain. Probably work with 415 too.
  7. miguelitro

    miguelitro New Member

    i have diferents hardware 58 to 73 teeth and atack pinion 6/8/10 the chain have to types 25h and and bigger (i don,t know metric).
    now it,s dark and snowing outside but tomorrow i take pictures and post them
    i have many ideas to explain to you

  8. BiMoPed

    BiMoPed New Member

    I talked to Dave and he doesn't have any sprockets that fit

    Dax only has a 10 tooth for 1/2" pitch chain and the teeth aren't beveled

    Still looking for 11, 12 , 13 tooth sprockets with 6 splines for the 5 to 1 transmission.
    Last edited: Nov 29, 2010
  9. 5-7HEAVEN

    5-7HEAVEN Guest

    Last edited by a moderator: Nov 29, 2010
  10. miguelitro

    miguelitro New Member

    hello guys
    this is the idea to change the engine developments.
    string types riding the pocket are 25h (no trust me, is too fragile, or so it seems) so I will use thicker chain.
    sprockets attack, threaded onto the clutch with Metric 8 mm or 10 mm,
    in my case I will use 8 mm, because the axes of the cranks are the metric, and that's what I use as an intermediate step between the motor and the wheel.
    the engine is not in the same plane as the rear sprocket so I could use this axis to align all the elements.
    tarsier is the crown pocket bike and I had to machine the original hub of the wheel.
    a good choice would have been a flip flop hub but here it's hard to get and also expensive.
    I prefer the creativity of money.

    I'm looking forward to cutting and welding.


    Attached Files:

  11. 5-7HEAVEN

    5-7HEAVEN Guest

    I use a 5:1 pocketbike transmission. It connects to an 11-tooth engine sprocket to 63-tooth chainring. Using 8mm chain for this connection. Then I use a 30-tooth chainring sprocket with bicycle chain. This connects to 11t-34t rear cassette. I have a shift kit, and my first gear is 32.45:1.....

    In 8th speed, the gear ratio is 10.5:1.....for high speed.

    You do not have a 5:1 transmission, so producing a good working gear ratio is not easy. Using 8mm parts makes it easier to make gear ratio than bicycle chain or 415 chain. Maybe you can use 6-tooth engine sprocket to 15-tooth intermediate step at the jackshaft(axis). Then 10-tooth to 72-tooth on wheel hub.

    15/6 = 2.5...
    72/10 = 7.2.....

    2.5 x 7.2 = 18:1 gear ratio.....good starting point.

    Find a rear hub for disc brake. Then drill 72-tooth sprocket to bolt onto disc brake flange.

    That should work.:detective:
  12. miguelitro

    miguelitro New Member

    I have ignored and I bought a gear box, with much pain in my heart and pocket as the cost of shipping from use are high.
    if this kit works well enough implificar hope the matter.
    we'll see

  13. 5-7HEAVEN

    5-7HEAVEN Guest

    Your English is hard to understand. Do you have a friend who can help you
    write what you need? I mean no disrepect. I just want to help.

    This is what I don't understand:

    "implificar hope the matter"

    Comprendo...I hope this simplifies the matter.:idea:
    Last edited by a moderator: Dec 3, 2010
  14. quay1962

    quay1962 Guest

    Welcome to MBc good luck on all your endeavors!
  15. miguelitro

    miguelitro New Member

    google translator

    sorry man.

    my english is elemental an d i use the translator (copy and paste) and if you don,t be care writting the translation is wrong.
    sorry again.

    i follow your example and i bought a gearbox.

    i mount it when i recive it. i hope simplify the final result

  16. 5-7HEAVEN

    5-7HEAVEN Guest


    The gearbox is simple. Did you mount it on engine or bicycle?

    Do not forget to put oil in gearbox.

    You can use bicycle front sprocket with 44 teeth to connect to 10-tooth gearbox sprocket. Use bicycle chain.

    The inside front sprocket has 32 teeth. Use bicycle chain to connect to rear derailleur.

    It is cheaper if you do not use pedals, but the front shaft might need to be widened to line up the 44-tooth sprocket with engine sprocket.