50 tooth sprocket?

Discussion in 'Motorized Bicycle General Discussion' started by jmr3394, Jun 12, 2010.

  1. jmr3394

    jmr3394 New Member

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    Does anyone here use a 50 tooth sprocket? What's the average top speed of a bike with a 50t?
     
  2. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    The top speed of a 2 stroke engine with a 50T sprocket will probably be 20 MPH!!!
     
  3. Tim_B_172

    Tim_B_172 New Member

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    20 If you are lucky. I run a 48 tooth and my top speed on flat ground is 28mph. I need that bigger sprocket though, I live in an area with a lot of hills and my house is on top of a great big one. Honestly, 28 is fast enough for me though.

    We'll get a real test here sometime next week, I am building a hill climber. A Schwinn Del Mar with a 56 tooth sprocket. It's for my Dad, he wants that huge sprocket so that he can haul heavy loads of groceries up the big hill. The 415 chain he ordered just came in today, then I just need to put together a long exhaust pipe like he wants and we'll be in business. I'm just waiting for my next day off from work now. ;)
     
  4. taddthewadd

    taddthewadd New Member

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    I have a 54 tooth sprocket. I wanted one this big because I built this bike primarily for off-road and for fire roads in the mountains that are very steep (can barely make it up them on a non motorized bike in first gear). It has plenty of instantanious torque. When I ride it on a flat road I think it will go 20 but rides more cumfortably around 15 mph. The cool thing is it goes from barely rolling to 20 very quickly (seems like about a second). I also have a 38T and it is too fast for my comfort and at slower speeds the engine struggles. It is like my Yamaha R6 sport bike, is only happy when going fast. I like cruising around 15mph with the big sprocket on the road. It is more like the normal speed of a bicycle but the engine does the work. One other thing is I think it is much easier on the engine and will make it last longer. The load put on the engine with the smaller sprockets can't be too good. With the bigger sprocket it effortlessly sings along very smoothly and less four stroking.
     
  5. jmr3394

    jmr3394 New Member

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    Thanks Tim and tad! I think i agree that 20mph is a pretty comfy speed as opposed to 30 where it feels kinda shaky and unstable. 50 tooth it is!
     
  6. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    We ride @ 40 MPH with no problem! ;)
     
  7. jmr3394

    jmr3394 New Member

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    Ya I put the 50 on today and got 30
     
  8. bangbang880

    bangbang880 New Member

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    Do you notice a big difference when climbing hills with your new 50?
     
  9. 5446

    5446 New Member

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    How is it now for hills? All I have here are hills most I cant get up. Do you have a shift kit?
     
  10. Tim_B_172

    Tim_B_172 New Member

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    Wow, I kinda forgot about this thread. Well, the 56t sprocket bike that I put together actually worked quite well. We were seeing speeds of about 25mph on flat ground, and it climbed hills without braking a sweat. That bike is currently grounded pending some major engine work. It has a very nasty vibration (like rattle you're fillings out NASTY) at the top end which I think is caused by improper installation of the crankshaft weights.

    It's an older engine and it always had that problem which is why Dad stopped using it to begin with, so there's no chance of exchanging it.
     
  11. 5446

    5446 New Member

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    Thanks for the reply. Soooo is that speed with a shift kit?
     
  12. Salty Gator

    Salty Gator New Member

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    If there's no hope of exchanging the engine on your Dad's bike ,there is an excellent sale of replacement engines from Zoom....$59.95 for a 49cc motor and $69.95 for the 80cc motor.....here's the site....I use Zoom kits exclusively and have never had an issue other than a bad carb once....they use a much larger intake pipe and port also....makes a big difference....
    Zoombicycles **BLOWOUT SALE** Replacement Engines | EHBC Distributors Ltd

    Hope this helps,
    Salty.shft.
     
  13. Tim_B_172

    Tim_B_172 New Member

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    Hi Salty, I've seen that sale. I almost bought a couple of engines myself just to put on the shelf for future builds. I showed it to the old man, I'm not sure if he ordered one or not. It's not really urgent anyway, he has another bike up and running.

    5446, No, no shift kit. It's installed with a stock rag-joint. I don't really understand how you would use a 56 tooth sprocket with a shift kit anyway.
     
  14. Nitrohorse

    Nitrohorse New Member

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    I have a 50t with a Chinese 4 cycle. I weigh about 230 and combine my weight with the hills here in N.E. PA the 50t is a necessity. I can hit 21mph, but I usually cruise around 16-18 mph. To each his own, but I enjoy the lower speeds (older age?) and the torque to pull my "full size figure" up any hill in my area. My favorite ride is to the local diner early on a Sunday morning for a plate of home fries, eggs, and scrapple. I'm sure that if the engine could talk, it would ask me to skip the big breakfast and have a small muffin (no butter), black coffee, and fruit instead....lol.
     
  15. bangbang880

    bangbang880 New Member

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    That sounds fun and I think your 4 stroke is happy you take him to breakfast . I don't think he minds the butter! : )

    Thanks for your response I wish we all had test bikes around or that it was easier changing your sprocket with rag joints.
    Have fun
     

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