Some help with centrifugal clutch install

Discussion in 'Motorized Bicycle General Discussion' started by geoldr, Oct 11, 2011.

  1. geoldr

    geoldr New Member

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    Not yet. When I get home from work today I'll try pulling off the gear
     
  2. geoldr

    geoldr New Member

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    Ok. I was able to get the gear off. Much easier than I thought it would be. I see now what the cut out is. In the shaft there is that half moon woodruff key sticking out. So, if I take the centrifugal clutch, and cut away about as much as there is in the standard gear, it should be good to go right?
     

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  3. GearNut

    GearNut Active Member

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    Exactly, but don't make the new groove too deep. You don't want to allow the woodruff key to be able to move up and out of the notch in the crankshaft.
    Also, you can make it as long as you want to, but making it full length of the clutch hub is creating more work for yourself than necessary.
    When you get close to being finished with the groove, cut a little at a time and check the fitment frequently until you get a perfect fit. Sneak up to perfection rather than trying to do it all in one cutting session.
     
  4. rohmell

    rohmell Active Member

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    When trying to fit everything be careful. Don't forget that when installing the CC you will be forcing it onto the crankshaft's taper, don't mistake that for an ill-fitting key/keyway.
     
  5. GearNut

    GearNut Active Member

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    Very good point, rohmell!
     
  6. geoldr

    geoldr New Member

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    Hey guys. So today I installed it. First I grinded down the 3 clutch pins, and it doesn't rub, no need for extra gaskets.
    However I am having a hard timing putting the actual CC on the shaft. I got it on there as far as it will go, I made the notch for the key and everything, and it's all good, but how do I get it to go the extra couple MM? Here is a pic of what it looks like.
    I don't think the notch is the problem, it's as deep and as long as the standard gear. I think its that widening part at the end that I don't know how to overcome. Do i just hammer it on or something lol I have no idea. Or should I make a gasket and fit this cover on like this. I don't know. If I put like.. two or three washers in between the big cover and small cover it will be OK. But does that mean the CC isn't on all the way?

    I took a chance and turned it on without the cover. It worked very well. And it was a blast to start from a standstill without pedaling. Besides, I can't really pedal, not enough clearance. That will be the next part of the install. Who needs pedals with this clutch anyways :p
     

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    #46 geoldr, Oct 20, 2011
    Last edited: Oct 20, 2011
  7. vincent713

    vincent713 New Member

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    So the clutch cover won't close all the way because it's hitting the clutch? I read somewhere on here that they cut the bolt about 2-3 mm so that the clutch will go in further. You also want to put another small lock washer on top of the washer that came with the clutch. Did you try bending the crank with a pipe? Glad to see that you got it running. My gasket came in today, I will work on it this weekend and report back.
     
  8. geoldr

    geoldr New Member

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    I haven't tried bending it yet, for the way it works, I think that's going to be the last step. What do you mean cut the bolt? The bolt that goes into the crankshaft, cut that by 2 or 3 mm? That would help if that was how to fix it. Yeah, I'm not completely done yet, so tomorrow hopefully I can get it all fit right, and install the washers and lock washer.
     
  9. vincent713

    vincent713 New Member

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    Yes cut the main bolt that holds the new clutch. That is what I've read somewhere in this forum.
     
  10. rohmell

    rohmell Active Member

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    The mounting bolt could be bottoming out, so you can cut 2 or 3 mm off of it, no harm done, but then you have to make sure that the cut end is nice and flat and tapered so that it can engage the crankshaft threads easily and correctly, I always add a lockwasher, it's an easier solution.

    Also, you can use use your Dremel tool to slightly enlarge the taper on the CC, or turn down the crankshaft slightly.

    Don't hammer it, you don't want to cause any damage to the bearings and possibly oil seals on the crankshaft.

    Perhaps the easiest solution is to make gaskets to take care of the spacing gap of the small cover, then you can go out riding and enjoy your new centrifugal clutch, and take care of the final fitting at a later time at your leisure.
     
    #50 rohmell, Oct 21, 2011
    Last edited: Oct 21, 2011
  11. vincent713

    vincent713 New Member

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    When you mention "the taper on the CC" what exactly is that?
     
  12. geoldr

    geoldr New Member

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    Yeah, thats my question too. Is it the bottom part of the gear area? Sorry for the bad edit, lol not very artistic.

    Also, since the clutch doesn't fit all the way, that means the gears aren't full 'on'. Like its only on 2/3 of the way. That's ok?
     

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    #52 geoldr, Oct 21, 2011
    Last edited: Oct 21, 2011
  13. vincent713

    vincent713 New Member

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    That notch looks pretty rough, did you have a hard time cutting it? What tools did you use? As long as it works that's all that matters right? .shft.
     
  14. rohmell

    rohmell Active Member

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    The crankshaft and clutch shafts used in these engines are skinny at the end. The further you go in, the fatter it gets, it is tapered.

    [​IMG]

    [​IMG]
     
  15. rohmell

    rohmell Active Member

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    So, essentially, if you want the clutch to go further in on the crankshaft, make the centrifugal clutch hole a wee dab bigger, or make the crankshaft diameter a wee dab smaller.
     
  16. vincent713

    vincent713 New Member

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    Rohmel,

    Did you run into these issues when you installed yours? Would it be easier to just use the lock washer to make the CC go in deeper?
     
  17. geoldr

    geoldr New Member

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    Ok, so I took some pictures of what rohmel was talking about, because ive figured it out. Ive also taken a video of how it rides. However I have to go right now, but as soon as I have time today hopefully in a couple of hours I will upload
     
  18. rohmell

    rohmell Active Member

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    I have installed about 15 centrifugal clutches so far, they are now standard equipment on all by builds.

    Every engine is different. On some, the clutch goes on easy, no problem, but on others, I have to shave the crankshaft taper a little bit for a good fit.

    On my first few builds, I did the keyway cutting thing, but later, I stopped, and have not had any problems.

    I always add a lockwasher, I feel better knowing that there is some sort of lock to keep the bolt from unscrewing.
     
  19. geoldr

    geoldr New Member

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    Hey guys. Just got some free time, I can combine the videos and upload to youtube some later time tomorrow hopefully. But here are the fitment pictures I was talking about. I have a 10 mm socket, which seams to be the exact size of the crankshaft.

    The first image displays the socket as far as it will go in the standard gear. It goes in all the way without issue, because there isn't any taper.

    The second image displays the same socket, but now in the CC. All the way it can go.

    The third image displays the difference in fitment. The top notch is how far the standard gear will go, and that's all the way inside. But the lower notch, is how deep the CC clutch goes and stops. So it's only in half way!

    I have a feeling that even with the woodruff key, this still isn't exactly safe.

    What do you guys think? And what should be my next best course of action to take?
     

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    #59 geoldr, Oct 22, 2011
    Last edited: Oct 22, 2011
  20. chinabase

    chinabase New Member

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    You are really nice,tks :)
     

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