1. 4 Stroke Husqvarna Motorcycles Made In Italy - About 1989 to 2014
     TE = 4st Enduro & TC = 4st Cross

Kush Sprockets

Discussion in '4 Stroke' started by TE450_guy, Dec 11, 2010.

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  1. TE450_guy Husqvarna
    AA Class

    Location:
    London, Ontario
    I posted this message to an existing thread and thought it deserved it's own thread:

    <<Well this week I got my Kush Sprocket from AU and it looks like the old style one that failed. I'll email Ryan and see if he did anything to the bonding process to make this one work. I thought they we changing the design to enclose the rubber dampers but this one is in plain steel and fully exposed.

    [IMG]

    [IMG]


    Notice that they are using a pin in the casing to hold the rubber dampers in place?

    We have almost 6 feet of snow and I have 4 ribs that are broken so I won't be able to test this thing out for a few weeks!

    Anyone else get one of these? >>
    TE450_guy, Dec 11, 2010
    #1

  2. rajobigguy Administrator

    Location:
    So.Cal.
    Yes I received one last week but have not yet had the opprotunity to try it out.
    I know that Kush was having some difficulties with the production and quality control from their manufacturer for a while. I was also under the impression that the new design would have the elastomers fully encased but maybe they found a better bounding solution and didn't need to modify the design.
    The weather in my neck of the woods is still good so I will be useing and abusing the sproket soon and do a full report on it in the near future.
    I hope that they have all the problems worked out, Ryan seems like a very nice guy that wants to bring a nice creative product to market.
    rajobigguy, Dec 11, 2010
    #2

  3. TE450_guy Husqvarna
    AA Class

    Location:
    London, Ontario
    rajobigguy,

    I won't sleep until you get that report done!

    I'll install mine as soon as the bones join and feel a bit better. Ryan has been great so far, he gets back to me within a couple of days, in fact, I just asked him about this sprocket and so I'll paste his comments when I receive them.
    TE450_guy, Dec 11, 2010
    #3

  4. Phoenix Husqvarna
    AA Class

    Location:
    Oklahoma City, OK
    Husqvarna Motorcycle:
    2009 TXC 450
    Other Motorcycles:
    2 Ducs, 14 GG 200, 13 Husa 300
    Interesting. What is the benefit of using this sprocket over say a standard steel or aluminum sprocket? Is it easier on the driveshaft?
    Phoenix, Dec 11, 2010
    #4

  5. rajobigguy Administrator

    Location:
    So.Cal.
    Same as a cush drive hub or clutch. It takes some the shock out of the drivetrain.
    rajobigguy, Dec 11, 2010
    #5

  6. Darkside Husqvarna
    AA Class

    Location:
    SF Bay Area
    Husqvarna Motorcycle:
    none left
    Other Motorcycles:
    beta, ktm, aprilia
    That's very cool looking. Never seen that before. I hope it works as well as it looks. Looking forward to a report. Thanks for posting pics.
    Darkside, Dec 11, 2010
    #6

  7. Leepet Husqvarna
    A Class

    Location:
    Canberra, Australia
    I don't see how the elastomer could be more enclosed. I don't know what the old design was like but the exposed sections look like they are going to provide the cushioning and need to be able to be freely compressed to do their job. I don't know how they could be enclosed while allowing some movement.
    Leepet, Dec 11, 2010
    #7

  8. rajobigguy Administrator

    Location:
    So.Cal.

    A simple metal shield on both sides of the elastomer that is affixed only to the inner or outer ring would still allow free movement but would trap the elstomers from being squeezed out the side, which I believe is the problem that some had with this arrangement. Like I said they may have found a better way of bounding the elastomer and don't need to do any additional trapping. I hope that is the case and the product performs well, they seem like they are really trying to come up with a nice product.
    rajobigguy, Dec 11, 2010
    #8

  9. Squidman Husqvarna
    B Class

    Location:
    Riverside, CA
    Your photos make it look like there are a few pins missing from the sprocket. Is that the case?

    I'd be concerned that any lateral motion at all would cause the outer ring to separate from the inner ring. Of course that is rare with a chain drive I think, but still, it would worry me. Can you tell if there is any kind of dove tail at the metal-metal interfaces that would prevent this?

    The concept seems really cool/comfy but I'd be worried about having a major failure and the outer ring separating from the inner if the only thing holding them together is some kind of elastomer at the rubber/metal interface, especially when under load like during a hard acceleration or hill climb. I'll be curious to see how you like it and how it holds up.
    Squidman, Dec 11, 2010
    #9

  10. rajobigguy Administrator

    Location:
    So.Cal.
    There are ball bearings in a grooved slot between the inner and outer ring. I think that it would be almost impossible for the two rings to separate. My only concern is the possibility of losing the elastomer segments but I don't want to even speculate on that possibility until I've got few miles on it. This could be a real saving grace when it comes to putting bikes that are primarily designed for dirt on the hwy. and I'm going to remain optimistic until I see otherwise.:thumbsup:
    rajobigguy, Dec 11, 2010
    #10

  11. TE450_guy Husqvarna
    AA Class

    Location:
    London, Ontario
    I heard from Ryan over the weekend and this sprocket is the new and improved one, please read what he has to say:

    <<< Hi Dave,

    Yes,well, its a modified design. Our new design was also good (clamped in PU), but we changed to a better material which bonded to steel with more strength than the material itself (ie. the material fails in peel tests before the bond) This allowed us to use the orginal design. One other thing that changed is the bond is now between the steel outer ring and the PU, not the aluminium (which would peel due the squashing/moving action).

    Cheers

    Ryan >>>>
    TE450_guy, Dec 13, 2010
    #11

  12. MXRider Husqvarna
    A Class

    Location:
    Virginia
    Husqvarna Motorcycle:
    None
    Other Motorcycles:
    2009 Yamaha YZ250F
    I still don't trust them until they are proven, redesign or not.
    MXRider, Dec 13, 2010
    #12

  13. rajobigguy Administrator

    Location:
    So.Cal.
    Well mine is going on this weekend and will see the most abusive things you can do to a sproket (aggressive riding on ashalt), so I guess we'll know in few weeks how well they work. I have a little experience with urethane bonding to metal and I can tell you that if it is done right you're almost as likely to tear the metal as you are the urethane.
    rajobigguy, Dec 13, 2010
    #13

  14. crillyiv Husqvarna
    AA Class

    Location:
    Ventura, CA
    Is it too soon to ask for an update?

    It's not like it's been raining around here or anything.

    How do they bond the metal and the shock absorbing material?
    crillyiv, Dec 19, 2010
    #14

  15. rajobigguy Administrator

    Location:
    So.Cal.
    It's too soon to ask for an update from me. It's been raining relentlessly in my neck of the woods. I'm not sure what process Kush uses to bond the elastomer to the parent material but there are several ways to do it, for instance you could use a two part catalyzed urethane and do a vacuum impregnation or you could use thermoforming with a injection mold process both of which would create a very tenacious bond.
    rajobigguy, Dec 20, 2010
    #15

  16. crillyiv Husqvarna
    AA Class

    Location:
    Ventura, CA
    The update question was meant as a joke. We live in the same area.

    Thanks for the info on the ways to bond the different materials.
    crillyiv, Dec 20, 2010
    #16

  17. racedesert_ Husqvarna
    B Class

    Location:
    Henderson
    Where do you buy Kush Sprockets?
    racedesert_, Dec 22, 2010
    #17

  18. TE450_guy Husqvarna
    AA Class

    Location:
    London, Ontario
    TE450_guy, Dec 22, 2010
    #18

  19. racedesert_ Husqvarna
    B Class

    Location:
    Henderson
    Thats more or less what i got. I hope they didn't go under, no joke implied. I like the concept.
    racedesert_, Dec 23, 2010
    #19

  20. rajobigguy Administrator

    Location:
    So.Cal.
    They had manufacturing/quality control issues for several months. In the mean time the back order list got huge. From what I understand, now that they are happy with the product they are trying to fill all the back orders and everything that they are receiving is already spoken for. I hope that they are past all the problems, I like seeing someone come up with creative solutions.
    rajobigguy, Dec 23, 2010
    #20
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