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  1. #1
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    SB66c no bumper stop!

    Hey guys,

    Had a worrying first ride of my SB66c last night. I was playing about in the street and doing some hops off kerbs as you do and heard this alarming ping/crack sound on landing fairly hard off a kerb. On closer inspection, it appears the Switch eccentric has gone back on itself, so rather than sit at 3 o'clock, it was at 10 o'clock! It appears the bump stop screw/rubber are missing so the Switch managed to swing under at the bottom of the arc and back up - so from say 3 o'clock through 6 o'clock and then up to 10 o'clock - when it should have bottomed out

    Any idea on what damage may have been caused? I've since had the shock mount off and moved the Switch back to 3 o'clock again. The bike shop say it should all be fine and have ordered me a bump stop to stick in, but I'm worried I may have damaged something on my brand new baby! Fortunately the chain was on the middle of the cassette, so the chain growth wasn't so much to kill my mech/chain (XX1!) - I think - as it appears to be working ok. Anything else I should check out?

    Cant believe it was missing from the factory

  2. #2
    undercover brother
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    My bumper stop was shredded when I pulled it apart last week after about 3-4 months of aggressive riding. Yeti claims that this is a wear part and will need replaced periodically. Since it was worn, I started hearing the same click, but the switch mechanism didn't move on itself like in your case. At most, you make have some light gouging inside the slot of the switch mech, but that shouldn't have any effect. Although if something were damaged, I would make damn sure that you feel it should be replaced by Yeti for free since it was the first ride.

  3. #3
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    Oh yes I will be making sure this is all on Yeti (or Silverfish our UK distro) if anything is damaged. The whole bolt and rubber are missing, there's just a threaded hole there! As there is no bolt, I expect there isn't any damage in the Switch eccentric as the bearings are free to keep spinning, its more what's happened to the shock/linkage that I worry about and what the knocking noise was, as if it had struck the frame somewhere or something.

    I can see how the rubber will be destroyed over time if this is the bottom out protection it has. The fact the shock itself didn't appear to bottom out and stop it rotating all the way around, suggests that the rubber is there to do that and that if you are bottoming out then it will take its toll on the rubber.

    Quite a scary first ride when I worked out what had happened and what it could have done to my XX1 mech if I had been in a lower gear. Just have to wait for the LBS to get the bolt and rubber to me so I can enjoy the bike! I might order a new rubber while I'm at it so I have a spare.

    I hope Yeti read this and can put my worries to rest

  4. #4
    undercover brother
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    Quote Originally Posted by Chris`I View Post
    Oh yes I will be making sure this is all on Yeti (or Silverfish our UK distro) if anything is damaged. The whole bolt and rubber are missing, there's just a threaded hole there! As there is no bolt, I expect there isn't any damage in the Switch eccentric as the bearings are free to keep spinning, its more what's happened to the shock/linkage that I worry about and what the knocking noise was, as if it had struck the frame somewhere or something.

    I can see how the rubber will be destroyed over time if this is the bottom out protection it has. The fact the shock itself didn't appear to bottom out and stop it rotating all the way around, suggests that the rubber is there to do that and that if you are bottoming out then it will take its toll on the rubber.

    Quite a scary first ride when I worked out what had happened and what it could have done to my XX1 mech if I had been in a lower gear. Just have to wait for the LBS to get the bolt and rubber to me so I can enjoy the bike! I might order a new rubber while I'm at it so I have a spare.

    I hope Yeti read this and can put my worries to rest
    Your chain should be long enough that when in the biggest ring in the rear, you can fully compress the suspension to bottom out and not rip the mech off.

    But I had my LBS order about a dozen from Yeti, and I'll probably by 6 of them at $1 a piece and make it a schedule to replace it every month or so.

  5. #5
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    Chain size is correct for when the Switch is working properly. So if its at the standard 3 o'clock position and rocks back to say 1 o'clock and then forward again to 4 o'clock as its meant to then there is the right amount of slack.

    What there isnt enough slack for is when the Switch manages to spin itself round 180 degrees so its at 10 o'clock as happened last night. This pushes the rear axle back say 20mm more, then when in big ring there isn't enough slack!

    This might help:

    Normal Switch eccentric position:





    Backwards Switch eccentric position (past bottom out position)




    Look no bolt!


  6. #6
    undercover brother
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    The irony in the "QC" sticker...

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