Multi Speed Chain Drive

Discussion in 'Rack Mounted Engines' started by kerf, May 28, 2009.

  1. kerf

    kerf Guest

    As some of you already know, I'm a little unstable when off my medication, this may prove to be no exception. I have a Staton chain drive, left side output, currently setup as a two speed, works fine. What I've thought about may be a little far fetched and I would like input, negative or positive. Goes like this:

    Step 1.
    Convert gear box to inside drive.

    Step 2.
    Remove pedal crank and install backward, putting chain ring on left side, driving left hand freewheel on Staton hub. This results in a one speed, which is all I ever use anyway. Also pedal threads will be back wards, don't know if that will be a issue or not.

    Step 3.
    Rotate dérailleur as far forward as possible to place idlers in a more horizontal position.

    Step 4.
    Run chain from inside drive sprocket to right side 7 speed freewheel. I figure at least a 4 speed maybe 5 would be possible before chain alignment became an issue.

    If chain routing to the dérailleur became an issue, maybe a wide ball bearing urethane roller could be employed to direct the chain. It should allow the chain to slide sideways for shifting.

    I haven't been thinking about this very long, there has to be some impediment I've overlooked. What say you.
     
    Last edited by a moderator: Dec 16, 2015

  2. Happy Valley

    Happy Valley Active Member

    Sounds doable Kerf, if the left side crank reversal became a problem with pedals loosening you could always use a crank off a tandem.

    One thing I'm missing and maybe it's implied but this would mean reversing the engine and gearbox as well correct, driving off the right side?
     
  3. kerf

    kerf Guest

    The Staton box comes in two versions, outside (left) drive and inside (right) drive. I have the outside drive but it can be converted by drilling the right side of the case through the output shaft bearing and reversing the shaft. Someone, I can't remember who, had that idea and called David Staton, as I recall, he said it would work.
     
  4. Happy Valley

    Happy Valley Active Member

  5. kerf

    kerf Guest

    Both of those photos show the drive on the left hand freewheel, I would be like the Nu Vinci, except I would be driving the dérailleur freewheel.

    http://www.staton-inc.com/Details.asp?ProductID=3249
     
    Last edited by a moderator: Dec 16, 2015
  6. DetonatorTuning

    DetonatorTuning Active Member

    kerf,

    you might want to look into putting some kind of chain guide half way between the BB and the derailleur.

    this will triangulate the lower chain run keeping the chain approach into the derailleur flat and keep the derailleur from being drawn up into the bottom of the cassette.

    if you have a standard 3 piece crank i don't see why you can't just flip it to the left side. you shouldn't even need a freewheel at either end on the left because the cassette freewheel will see the pedal force from that side as a coast condition.

    how do you seal up the former left shaft opening ?

    steve
     
  7. duivendyk

    duivendyk Guest

    In principle it could work if deraileur can be made to behave,lack of sufficient chainwrap. might be a problem.Some practical issues,need freewheel sprocket on gearbox for 3/32? " chain,max. cassette cog 32/34T I think,what overall ratios could be feasible?,
     
    Last edited by a moderator: May 28, 2009
  8. kerf

    kerf Guest

    1/16" rubber bonded over the opening is what I'm thinking.
     
  9. kerf

    kerf Guest

    If memory serves me, never has before but if it does, I've got a 13-15-17-19-21-24-34 freewheel. Using the three largest freewheel sprockets with a 21 tooth on the output it should be 30.36/1 21.43/1 18.75/1 16.96/1. I'm currently running 18.75/1 & 23.08/1.
     
  10. kerf

    kerf Guest

    The one fly in the ointment, as far as I can see, is the chain geometry around the dérailleur. I don't want to tear apart my bike only to find an insurmountable issue. I need some type of test bed so I can try this idea in a low risk environment. Maybe a trip to the thrift store could provide me with a bike to test on.
     
    Last edited by a moderator: Dec 16, 2015
  11. duivendyk

    duivendyk Guest

    I agree,but it's worth trying out,if the chainwrap is too small the chain may start skipping teeth under load,increasing chain tension helps, but makes shifting more difficult.
     
  12. kerf

    kerf Guest

    By rotating the dérailleur as far forward as the lower dropout strut allows, only results in about 30% chain engagement. I don't believe that would work. If I rotate it about 120 degrees and place it between the upper dropout strut and the forward gear box strut, that will more that double the chain engagement. Lot of ifs though.
     

    Attached Files:

    Last edited by a moderator: Dec 16, 2015
  13. DetonatorTuning

    DetonatorTuning Active Member

    if you CAN get the derailleur to stay in that position you will be home free.

    steve
     
  14. kerf

    kerf Guest

    IF

    That's a big word to be so short!
     
  15. Happy Valley

    Happy Valley Active Member

    Would this setup require you to configure and mount a derailleur hanger in a new position,
    forward of the cassette? I suppose it wouldn't matter what position the derailleur ended up, bottom pulley up so to speak or upside down from it's standard operating position, but there might be interference from the seatstay or rear brake assembly.

    I just tried a spare derailleur in that forward position on a large frame, hardtail mtb and there would be clearance problems with the cantilever brakes it has.
     
  16. kerf

    kerf Guest

    Thinking as of now is to relocate the gear box struts, if necessary and pivot the dérailleur hanger around the rear axial. No doubt this will complicate rear wheel removal because the dérailleur will need to be unbolted. Having said that, rear wheel removal is already pretty tough, a little more won't hurt.
     
    Last edited by a moderator: Dec 16, 2015
  17. duivendyk

    duivendyk Guest

    That new position should work,there is fair amount of flexibility in mounting the gearbox although it might not look pretty.A word of caution about Staton type freewheels,like those on the gearbox output. The tooth profile is more 'triangular' than 'lost circle' shape of the derailleur type cassett cogs.As a result the chain has a tendency to ride up the sprocket teeth if chain slack permits it,which will be the case with a derailleur setup.
     
  18. kerf

    kerf Guest

    Freewheel adapter and a 3/32" track sprocket on the Staton output will be compatible with the dérailleur. That's what I'm running now and derailing #410 chain for my two speed. Wife thinks I'm out of my mind, doesn't understand about climbing mountains, I guess.
     
  19. duivendyk

    duivendyk Guest

    Trick her into to riding up one,sneakily like,if you have something handy&she will quickly come to appreciate that there is method to your madness after all. (just maybe).
     
  20. ... internal geared hub
     
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