Mechanical efficiency of chain drive vs roller drive

Discussion in 'Transmission / Drivetrain' started by mifletz, Dec 31, 2009.

  1. mifletz

    mifletz Member

    I was told that chain drive will deliver c30% more practical power to the rear wheel than roller drive.

    Is this correct?
     

  2. kerf

    kerf Guest

    A chain drive would be more efficient than a friction drive, owing to tire deflection caused by the loading of the drive roller. As to the 30% figure, I feel this is an inflated number based on personal experiences with both drive systems. The biggest drawback to the friction drive is wet roads, which causes the roller to slip. On the other hand they are less expensive, much lighter and much quieter than chain drives.

    I'm currently building another friction drive for my wife, she wants no part of a chain.
     
  3. give me vtec

    give me vtec Active Member

    Belt drive is best... friction drive is better than chain drive.

    I hate chains.... they stretch and tend to jump off the sprocket.
     
  4. Happy Valley

    Happy Valley Active Member

    There has to be loss of engine BHP with all drive configurations and tire deflection (or slipping if badly adjusted or wet) is certainly the main culprit with friction drives.
    My thought has always been since most FDs are direct drive off the crankshaft, tire deflection pretty much accounts for any losses with a friction drive system though.

    Most chain drives have to go through some kind of primary and secondary speed reduction. Gearbox gears, internal chains, belts each suffer losses and main drive chain and sprockets add to these losses as well.
     
  5. mlcorson

    mlcorson Member

    I have both, and under ideal (dry) conditions, I haven't noticed a significant difference in power transfer. Both are 4 cycle R/S engines - A Staton chain drive and a friction drive. My friction bike was a lighter bike to begin with, and with the friction it is much lighter than the chain drive.
     
  6. mifletz

    mifletz Member

    In ideal conditions, ceteris paribus, can one therefore not expect a significant difference (ie 10%<) in performance (in acceleration, top speed and steep hill-climbing ability) between chain and roller drives?
     
  7. mlcorson

    mlcorson Member

    Ceteris paribus, I have not noticed that much difference. As always, caveat emptor. But definitely carpe diem with either one. ;-)
     
  8. HoughMade

    HoughMade Guest

    Illegitimi non carborundum
     
  9. Mountainman

    Mountainman Active Member

    don't think so -------------- but
    I have been riding a friction for a while now
    and truly do enjoy the little THING

    but a chain drive is very hard to beat
    especially in any kind of damp or wet conditions

    I also have one Lady friend with a friction
    she one day did not get the to the wheel roller adjustment just right
    eat that tire -- she needed a new tire

    as far as assigning a % as just to how much better
    a chain drive is over a friction
    Mountainman will take a stab at about --- 5 to 20 % better ?????

    living in a mostly sunny place here -- closer to the 5 %
    if it was wetter it would for sure be closer to 20 %

    ride that THING
     
  10. mifletz

    mifletz Member

    I've just taken my Robin engine off its roller drive mount and tried it on a chaindrive bicycle, and there's definitely 15-20% more power at the wheel, which makes all the difference going up steep hills. And no slip in the wet. I'm now convinced about having to change to chain.

    The customs tax in Israel being 100% which I'm not prepared to pay for a chainkit shipped from the USA, so the bike shop here are going to fabricate me a mount, them all being professional metal workers who have spent their lives welding Merkava tanks!
     
    Last edited: Jan 5, 2010
  11. professor

    professor Active Member

    Mifletz, that was a very good test you did. I have been on the fence about which drive to use for my gas/electric. I'll use chain. We get a lot of rain here too.
     
  12. Happy Valley

    Happy Valley Active Member

    It's useful to note the applied power you're feeling will also be relative to the respective gearing aspects resultant and present in the the two drives.
     
  13. mifletz

    mifletz Member

    My question is: although this chaindrive set up is crude & brutishly Israeli, is there anything markably better or worthwhile available that would deliver better performance or be notably lighter, pending the availability of Staton's axledrive system?

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    Last edited: Jan 30, 2010
  14. professor

    professor Active Member

    well, how does that pictured system work out?
     
  15. darwin

    darwin Well-Known Member

    Well I have a Doctorate in common sense and a Masters in hard knocks, a chain drive is the efficient way to deliver power to the wheel.
     
  16. loquin

    loquin Active Member

    The chain drive itself is VERY efficient at transferring power from sprocket-to-sprocket. Properly adjusted, greater than 98 percent efficient. However, the gearbox (or belt reduction) efficiency, generally required to reduce the drive sprocket RPM, must also be considered.
     
  17. mlcorson

    mlcorson Member

    No experience with this system, but I like the way it fits on the bike. Uses a smaller 25CC engine. Bimoto
    http://www.bimoto.pl/index.php?s=5&l=en
     
  18. loquin

    loquin Active Member

    What size chain does it use? If you swap out the drive sprocket with a freewheel, you could coast with the engine idling... (very little drag with just the chain /driven sprocket turning.)
     
  19. mifletz

    mifletz Member

    Have you a photo of the type of freewheel you mean?
     
  20. loquin

    loquin Active Member

    They're thread-on freewheel sprockets. An example of a shimano freewheel sprocket is shown below. They're designed to thread on 1-3/8 inch, 24 TPI hub. Staton makes several freewheel adapters, to allow you to mount a freewheel to a shaft. His adapters can be used on shaft sizes ranging from 1/2 inch through 1 inch. Available sprocket sizes for this thread-size range from 16 teeth, up through 22 teeth, and I believe I remember seeing a few 25 tooth ones. There are also similar, thread-on freewheels with a flange, so you can bolt larger sprockets up tp them.

    Here's a link to his 3/4 inch adapter.

    There's another, me(ric standard thread-on freewheel, which threads onto 30mm X 1mm thread spacing, which allows smaller sprocket sizes. (as few as 13 teeth)
     

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    Last edited: Jun 7, 2010
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