What clutch/chain to buy for my sprocket?

Discussion in 'Motorized Tandems, Trikes and Recumbent Bicycles' started by Kenny'sID, Jul 7, 2016.

  1. Kenny'sID

    Kenny'sID New Member

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    I just got my sprocket and retainer in...the one at the following link...

    http://www.ebay.com/itm/291068614228?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

    ...and I now need to order a centrifugal clutch and chain for it. Best I can gather is the sprocket identifier is the number 415....is that correct, or are all these type sprockets 415? If so, is that all I need to look for when ordering the centrifugal clutch and chain or is there more too it?

    FWIW, it's going on a trike with a 3 horse 4 stroke so any advice on the amount of teeth I need on the clutch would be helpful as well. Thanks for any help.
     
  2. Kletus

    Kletus New Member

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    Hi Kenny. I put a 79cc 3hp predator in my trike with a 44 tooth rear sprocket and a 10 tooth centrifugal clutch sprocket and it just barley pulled it. 10-15 MPH wide open. I'm thinking that the rear sprocket needs to be mucho grande bigger. or you need the 212cc predator. The 3 Hp might work out if you use that 79cc transmission that Affordable Go Kart sells (AGK). Its a 2:1 ratio and that would work out to 8:1 total ratio with the rear sprocket you have. My bike has this set up.
     
    #2 Kletus, Aug 31, 2016
    Last edited: Aug 31, 2016
  3. Kenny'sID

    Kenny'sID New Member

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    Good info, Kletus...thanks

    Yeah 10-15 is ok but not qiute enough. I ran this a 22 w/the front hub motor and that was scary but I was hoping for a solid 18 or so mph with the gas drive.

    How bout the torque? When you say barely pulled it, are we just talking just top speed or barely getting it going from a stand still as well?

    My state only allows 49cc and I was just going to put a 49cc sticker on the 79 and hope to get away with it at the required inspection so, not sure I'd have a chance getting a way with the 212. I did try a 212 on it BTW, and it was nice...just right. Too bad they don't have enough sense to recognize the trike is heavier and allow more power, but that's our FL gov in action. Thanks again.
     
  4. Kenny'sID

    Kenny'sID New Member

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    BTW, got the clutch/chain, put it together and the new 79cc would only idle. I'm not bad with small engines but couldn't figure it out without taking it apart. It's as if they didn't drill the gas intake in the carb. Anyway returns take a lot of time with Harbor freight and am still waiting on the replacement.
     
  5. Kletus

    Kletus New Member

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    My thinking is that you really don't need all that power and speed but your engine RPM'S will be lower at the cruising speed you elect extending engine life. Also you might want to pull a trailer or something one day. An 8:1 ratio seems to be the magic number for a 79cc predator. Me, I slapped on a 212cc predator on the Schwinn Meridian Adult Tricycle and now I am waiting for a clutch to arrive. Waiting,waiting,waiting. LOL, I am also waiting for my son to get my pedal cranks bent so I can ride my 79cc monster bike
     
  6. Kenny'sID

    Kenny'sID New Member

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    I agree, we need a little headroom there for engine life. And I do have a trailer for this.

    The reason I ask about the torque is part of the reason I want the gas drive along with the electric to begin with. With my legs the way they are, I can't pedal, even a little so I need it to take off from a standstill on it's own. So when I think about it more, I'm only doing the gas engine as a backup so I'm not left stranded if the electric goes out. So in reality, the Gas won't be used much and if I do use it in emergency, I won't mind limping the bike home at 10 or so MPH.

    So with that in mind, do you recall if the 79cc got going from a standstill without peddling?

    Yes, this ordering everything online has it's advantages but the waiting is terrible. One forgets to order a few things or just doesn't know what they need to order till they need it, and you end up like me, with months into one bike, lol. Mine is a Meridan as well and as I say, I tried the 212 on it so, you're going to love it on that bike. :)
     
  7. Kletus

    Kletus New Member

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    It would take off from a dead stop but it was real slow and the engine was really laboring. I attribute this to the 4:1 ratio I was using. The engine really never peaked out even after it got going The reason I had the 79cc on it in the first place is I ordered the 212cc trike kit form gasbike and as usual they screwed up and sent me the wrong clutch. They sent a clutch with a 5/8" bore and the 212cc engine supplied with the kit required a 3/4" bore. My thought is you will probably have to increase your gearing ratio either with a large back sprocket or that transmission that AGK sells.
     
  8. Kenny'sID

    Kenny'sID New Member

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    Thanks, that's really helpful info.

    When I order form Gasbike I try to go through ebay, a few dollars more but they tend to pay more attention to what they are doing with the possibility of feedback and all.

    Yeah, a little more torque may be my best bet on this in spite of the speed loss.

    Care to take a rough guess at what tooth sprocket I should go with to get me going off the line, with light or no hills? Not holding you too anything... just a rough estimate would help me decide since we're talking the same engine/same bike. I presently have the 44 tooth also.
     
    #8 Kenny'sID, Aug 31, 2016
    Last edited: Aug 31, 2016
  9. Kletus

    Kletus New Member

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    You probably have a 10 tooth clutch sprocket so if you put on a 56 tooth sprocket that would be a 5.6:1 ratio where as now you have a 4.4:1 ratio with a 44 tooth sprocket. Don't know if the make anything bigger. Also with a bigger sprocket you will need a longer chain. Going to a larger rear sprocket in this case will not cost you top end speed as it may let your engine rev up into its power band for top end speed and actually increase low end torque for better dead stop take offs. The ratio on my 79cc 26" bike is 8:1 but it has AGK's jack shaft transmission. I think 8:1 is the correct ratio for the 79cc predator driving a 26" wheel. I think a 56-60 tooth sprocket is as big as you will find. Anything bigger might be impractical.
     
  10. Kenny'sID

    Kenny'sID New Member

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    A lot of good usable info there. Thanks for being so thorough, Kletus ...I'll have a lot easier time of figuring out how to go with this now. And some good news on the higher speeds to boot.

    Good luck w/the 212 build and thanks so much for the help.
     

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