best way to gear motor to wheel

Discussion in 'General Questions' started by michaelr123, May 11, 2011.

  1. michaelr123

    michaelr123 New Member

    hello everybody that has accomplished the awesome task of mounting an engine to a bike! i for one, am struggling! just a bit! I'm wondering how people are engaging their engine to the wheel.

    i'm ruling out friction drives cause they suck, but of course drivetrains and gearing and such become a difficult, expensive hassle.

    one of my biggest needs is WHERE DO YOU BUY GEARS???? i've looked all over and only found a few spotty places that sell a few gears, can anyone offer a suggestion as to were i can find spur gears for a drive train?

    the reason for all the trouble is because i know about gear ratios already (won't bug anyone with that) but i've devised a plan with a drive train that takes a chain input from my 60cc chainsaw engine that happens to be working now after alot of hard work, through a drive train (basically input 20 revolutions output 1 rev. 20:1 in that sense) and then bike chain sprocket that is on a shaft connected to the last gear on the drive train, which will run a standard 420 bike chain to the tire, and hopefully will be close to the magic 1:20 ratio im looking for.

    anyone have any comments on this idea? how did you do it?? basically i just need a pic of your drivetrain and the websites where you got your gears from, other wise i'm good to go, as far as i can find so far gears are really hard to come by without like buying in bulk from a manufacturer,

  2. spad4me

    spad4me Member

    You bit off a huge chunk of the world.
    Read this first.
    A friction drive in a dry level climate is very easy to do.
    Then there is belt drive like GEBE. Very nice!
    Then a scooterguy setup. I use this type of setup now.

    and finally a cheap place to buy sprockets and chains.
    Be careful with the sizes.

    Google for thats dax or sick bike parts for more ideas or just lurk here.
  3. michaelr123

    michaelr123 New Member

    i looked at the second link and your using a chainsaw just like mine, and only using a 1:5 ratio? does that work without the pedaling start? and am i wrong with my 1:20 ratio that i got off the internet?

    and by the way, i have a 420 chain on my mountain bike, what type of sprockets will fit this chain?

    and one more thing, how did you attach a sprocket to your chainsaw engine clutch? it looks all too easy in your pictures

    and one more thing, i saw belts for another idea to replace a chain drive, i can see how this would be alot easier but you still have to deal with the gear ratios and such right?
    Last edited: May 12, 2011
  4. Stan4d

    Stan4d Banned

    Hi michaelr123! Perhaps you missed this:
    Please reintroduce yourself. I will move the thread to a more appropriate forum.
  5. michaelr123

    michaelr123 New Member

    How to attach a Sprocket to the motor

    now that i have a better idea of how this is suppose to go, i'd like to know how people are going about getting a sprocket to run on the end of their chainsaw? are you just welding it to the bolt on the shaft? or a set screw kind of deal? and doesn't this by-pass the clutch of the chainsaw?? it's what it looks like you guys are doing, but i haven't found any forms at all that relate to this part of the build
    Last edited by a moderator: May 12, 2011
  6. srdavo

    srdavo Active Member

  7. michaelr123

    michaelr123 New Member

    hey thanks, that first video is great, is its really that simple? all i have to do is attach the sprocket to the outside of the clutch however i can do that? cause i can have that welded, to that bolt like i was talking about,
  8. ferball

    ferball New Member

    I am in the middle of a weed whacker build and here are a few things that I might suggest. Sprockets off of old kid coaster brake bikes are easy to take off and easy to come by weld them to the appropriate size nut and attach to a shaft this has worked great for some of my chain drive projects I did with an in frame motor.

    For my weed wacker project I am forgoing the clutch all together. The action of lowering or raising the spindle will give me all the "clutch" control that I think I will need. This is with a friction drive, but I am sure a similiar idea could be accomplished with an idler pulley type idea, similiar to the deck blades on a riding lawnmower.
  9. michaelr123

    michaelr123 New Member

    hey quick question, why does the other post i made to this forum redirect me too this one? that one had some really good videos on it, any idea?
  10. Stan4d

    Stan4d Banned

    This is that post. Scroll up.
  11. michaelr123

    michaelr123 New Member

    quick question, are sprockets the same for #40, #41 and #42 chains? thats what it seems like from alot of websites
  12. Wheres my dog

    Wheres my dog Banned

    #42 chain as in 420 chain you mean???

    To my knowledge... 40, 41, 410, and 415 are all the same pitch size... now all of these are different widths which may not seat well on larger toothed sized sprockets!
  13. Bugsy

    Bugsy New Member

    I am an absolute noobie here, in fact, this is only my second post, so don't take me to seriously.
    My question is, why would you try to fit a chainsaw or weedwhacker motor to a bike when you can buy a complete kit with motor for only $125-$135? I suspect you will spend more than that trying to retrofit, plus have an inferior set-up when you are all finished.
    I am pretty tight with a buck, but even I can see what a huge value these kits are. How in the world can they make a motor, add in the chain drive, and the hand controls for that cheap? And, the darn things work great! :grin5:
  14. wbuttry

    wbuttry Member

    well it is like this people have to much bloody time on theyre hands and to darn much money to waste and people wanna see if they can improve on something that works good i gotta work for my money and sure the heck arent gonna blow it on something that wont work ........
  15. michaelr123

    michaelr123 New Member

    hey quick question, are 40, 41 and 42 chains all the same? will they all fit the same sprocket? thats the idea im getting from some websites,

    and problem with my clutch, the cup is on the inside, and the bolt faces out, if i can get a pic of it up, its a mcculloch pro mac 610 chainsaw, but the sprocket that takes the the chain of the saw is like sandwiched between the engine and the clutch cup i guess you'd call it? any suggestions on how to get something on the outside so i can weld a sprocket to it? im thinking like welding 3 pieces of metal to the outside of the cup and like bringing them around to the front and connecting them so i have something to attach the drive sprocket to, and thats running to a 72 tooth sprocket thats connected to 10 that will go to the cassette on the back, giving me a 24 something ratio thru like an 11 at highest, does that sound good?

    and i guess how do you get pics on here?
  16. Wheres my dog

    Wheres my dog Banned

    I am sure you are aware of this already...

    You do know that chainsaw engines are extremely loud?
  17. 5-7HEAVEN

    5-7HEAVEN Guest

    Not everyone uses cheap Chinese engines(HT, HS, HF clones) just because they're cheap. Some drive American (B&S), some ride Japanese because they're dependable(Tanaka, Mitsubishi).

    I work for my $$. I improve on things that work well. I ride Japanese engines for speed, power and reliability. :devilish:
  18. 5-7HEAVEN

    5-7HEAVEN Guest

    If you know about gears, you must know that the ratio you're proposing will end up burning up your clutch. You will also have to be rolling down a steep hill before your engine slightly assists your bike.

    Shoot for 14.32:1 in high gear, 35:1 in first gear.

    Your calculations have you at 7.92:1...:detective:
  19. spad4me

    spad4me Member

    This is what you are missing.
    It is a five to one transmission. It is the first stage of the total reduction. Gear Box "POWER TAKE OFF" BOLTS UP TO THE
    The output shaft has a ten tooth gear.
    PTO 10T 1/2 inch DRIVE SPROCKET STEEL . Fits
    Gear Box PTO and other gear boxes with 6 cog
    spline. New Style one Piece milled. ONLY $11.99
    The ten tooth output shaft drives the front (48 to 56) chainring freewheel jackshaft setup which is directly bolted to a 24 tooth sprocket at the front chainring.
    Instead of a front shifter I have two directly connected sprockets.
    These are available from sick bike parts. They are parts of their shift kit.

    My first gear is 39 to 1.
    And the highest of the useful speeds on my rear shiftable cassette is about 17 to one.

    I believe that 410 420 and BMX chains all have the same pitch. The side to side spacing of the end plates is different.
    I use KMC 710 or Kmc 910 or whatever I can find cheaply locally. I have used all the local lowes supply of 420 chain.
    I use a whipperman or equal multispeed chain of no more than seven speeds .
    The size changes over eight speeds (too thin for me).

    Here is a calculator that will help.
    Last edited: May 15, 2011
  20. 5-7HEAVEN

    5-7HEAVEN Guest

    I don't think a 5:1 transmission will bolt onto his chainsaw engine.:detective: