A new shift concept for the engineers....

Discussion in 'Motorized Bicycle General Discussion' started by ferball, Jul 26, 2010.

  1. silverbear

    silverbear The Boy Who Never Grew Up

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    Hey Jim,
    Understood, and that's how things should be with business first. Hopefully the sprocket cluster shift prototypes will work out and eventually become part of your production runs. All good things are worth waiting for.
    SB
     
  2. bowljoman

    bowljoman New Member

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    Yep, I'm of the mind that internal is the only way to fly.

    Good modern 3-speeds aren't going to explode.

    How come nobody has considered the SA s3x hub . Fixed gear 3-speed. Flipp it to the left side.

    They even have a dual sprocket model with freewheel on one side and fixie on the other.

    CVT is too much heat and friction. I spent more money on belts for a cvt than I did for the entire trike tranny.

    Also consider when you shift with a derailer, you are pulling the chain tight on top whereas , your setup, the wheel sprocket will put the slack to the top, increasing the chance to bind.

    Good luck. I wish I had your tools!
     
  3. Goat Herder

    Goat Herder Gutter Rider

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    You got a link to this subject of flipping the hub? Also I have to picture the free wheel un threading itself?
     
  4. bowljoman

    bowljoman New Member

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    Hello, I was mistaken. the fixxy and threads are on the same side.

    When flipped, you would use the fixxy, not the freewheel.

    The main idea, is 3 speed input on the left side, and it will still bump-start your motor, cause its fixxed.

    CW+S3X+article001+copy.jpg (image)
     
  5. bowljoman

    bowljoman New Member

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  6. LouieMCman

    LouieMCman New Member

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    What's the opinions on whether the 3 speed hubs will hold up to say a 5HP motor?
     
  7. BarelyAWake

    BarelyAWake New Member

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    Dunno, it may well be right on the edge... There was quite a bit of debate about the 3 speeds when I first decided to put a worked 66cc through a shiftkit and a Sturmey Archer X-RD3, yet roughly 3000 miles of abuse later it's still workin' as fine as the day it was new *shrug*

    I'd give it a shot, newer internally shifted hubs are pretty dang tough, I suspect most of the failures were with old, beaten & neglected hubs and improper shifting techniques, "skipping" between gears due to maladjustment & "speedshifting" (not backing off the throttle while shifting - causing a "slamming" effect on the hub).

    What "5HP" engine are you considering?
     
  8. camlifter

    camlifter Active Member

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    heres a link to a thread i started awhile back on flip flop hubs,
    http://motorbicycling.com/f3/ideas-rear-wheel-15585.html
    the 3 speed jack shaft hub i did on my silver bike is working great, i still have that bike, but it's only running a gx35 cc motor, i think it would hold up to a HT-china girl but not a 5 horse or harber freight, anything like a morini would kill it quick.
    with a flip flop hub you should be able to take a cassette apart, flip the sprockets so the tilt of the teath are going the right way and attach it to the left side of a flip flop.
     
  9. Goat Herder

    Goat Herder Gutter Rider

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    I am staring at a cog set right now. Looks like they cannot be flipped without doing some trick dremel work. Still have to account for the free wheel ratchet paws.

    Is there a left side 5 speed cassette set up I don't know about?
     
    #110 Goat Herder, Aug 12, 2010
    Last edited: Aug 12, 2010
  10. LouieMCman

    LouieMCman New Member

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    Barely, I had a friend tear up one of the older 3 speeds with a 5 HP, the newer ones may hold up if you don't beat on it. I'm working on a mini (Midi) project that I want a bigger motor on, say 10 HP, I've got bikes with torque converters and ones with jack shafts with a clutch. I'm thinking about using a jack shaft with the two clutch two speed setup. I've never seen or rode one but think they LOOK really cool. Here's a link to the build (I know it's a mini bike site don't kill me)...
    Indian Mini to Adult Size Mini - OldMiniBikes.com Forum
     
  11. BarelyAWake

    BarelyAWake New Member

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    laff - naw such links are fine by us... but apparently they won't letcha view pic links unless yera member :(
     
  12. bowljoman

    bowljoman New Member

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    I think if you increase the chain speed wrapping the 3-speed, it can handle the 5 hp. Reducing the amount of torque that is applied through the tranny, allows you to go bigger on power.

    If I sit in my scooter and pull on the drive chain by hand, I can move the scooter in first gear with my weight in it.

    Currently I have a ten to one ratio between my crankshaft and the transmission input sprocket.

    And the tranny to rear wheel is 1 to 1.25 with a 10 inch rear tire.

    So my overall ratio from tranny input to rear wheel is
    90%
    125%
    160%
     
  13. bowljoman

    bowljoman New Member

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    That is
    first second and third gear :
    90%
    125%
    160%
     
  14. bchowk

    bchowk New Member

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    So I'm stuck at one of the links that GH put up

    Sheldon Brown's Gunnar Street Dog Left Drive, 3-speed, Fixed-gear Bicycle

    I'm new to this so forgive me but....I read the flip flop wiki and it looks like that is NOT talking about running a chain on the left side but DOES have a gear on both sides, so the drive chain always on the right, flip the tire and change the gear, think I got that but still a little curious how the free wheel would work on both sides.

    So, here is what I KNOW I don't understand....How did Sheldon Brown flop that 3 speed hub over and have work rotating anti clockwise, how did he get that free wheel to work on the flip side....THEN if you (or I) could do that and hook that left side hub (likely with a larger input gear) up to a HT motor and your halfway there right?....THEN you'd need a right side drive gear and freewheel that worked in the CLOCKWISE direction for pedal power...

    So essentially we are looking for a hub that has TWO drive inputs (left and right) that will both freewheel as the bike moves forward, correct...Looks like Sheldon Brown is halfway there, how'd they do that?
     
  15. bchowk

    bchowk New Member

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    wait.....I just realized, on the left you would NOT want a free wheel, so one could still pedal start the engine....but you would still definetly want a free wheel on the right, right?
     
  16. silverbear

    silverbear The Boy Who Never Grew Up

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    Ummm,
    Right... flip the flopping gear to free the wheel and then what's left if that doesn't work but to walk the danged bike home, right? I believe one has to be a gear head to understand this stuff, which I am not. I just wait for the dust to settle and hope some smart person figures it out eventually so I don't have to pedal till my pants catch on fire trying to get up a hill. A shiftless waiter,
    SB
     
  17. Kevlarr

    Kevlarr New Member

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    I've been looking and looking but I can't find a supplier for this

    Evo 2 Two Speed Transmission
    [​IMG]

    It looks huge until you see what it goes on.

    [​IMG]
     
  18. silverbear

    silverbear The Boy Who Never Grew Up

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    The suspense is killing me. What's it go on? How would you set this up?
    SB
     

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