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  1. #1
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    eccentric hub slipping - any ideas?

    Since my rear wheel was up for replacement, I opted to simultaneously get rid of the tensioner and go with an ENO eccentric hub. Mounted it up, adjusted the brakes, and went for a smooth spin around the block - no problems...

    On the trail, grinding up a tough hill - bam, chain's off and I'm on the ground. I stop, realign everything, tighten the bolts. 10 min later - chain is slapping off the stays. I went home, cranked it tight with a long bar and tried again. This time I made it 30 min in before the hub rotated out of position and dropped the chain.

    What am I doing wrong?? I really like the concept of this hub, and after dropping the money, would like it to work for me. The frame is nothing unusual, a mid '90s steel Rocky Mountain, standard dropouts. The chain alignment looks fine, and based on a lack of apparent wobble, I think the dropouts are well aligned. I am at a loss.

  2. #2
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    Wow, I've had mine loosen a bit but never to the point of chain skip, and that is after two years of riding and racing. Are your drop outs clean, is paint chipping off that might help it loosen? I would check that first. The other thing you can do is fiddle with your gear ratio so that the axle is somewhere between the 3 and 12 o'clock position compared to the bolts. That way if it loosens your body weight will keep things tight. I hope that helps.

  3. #3
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    A lot depends on which direction the axle is located to tighten the chain. The best position is between 7 and 8 on a clock, that is, the axle is rotated backwards. In this position your weight is working to pull the eccentric backward, which will serve to tighten the chain rather than working to loosen it. All ENO's that I know of slipping were installed in different positions than this. All other positions will work to loosen the hub, leading to what you are experiencing. Tigtening the bolts will only serve to set the hub up to slip again. Reset the hub so that it's in the right spot, shouldn't have any issues at all. Mine hasn't slipped in 3 years, and I'm 200lbs and hammer hills. Cheers.

  4. #4
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    You need to take any paint off the dropouts that contacts the hub axle or bolts. That seemed to solve just about everyone I know of's problem. The paint is just too soft and slippery.

  5. #5
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    wasting time is exactly right about the axle placement being at about 7-8 o'clock. I figured that out the hard way. I'm another clydesdale and had the same problem.

  6. #6
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    when mounting the rear wheel are you doing this with the bike upside down or with the bike upright? Recommend upright. Also check that spacers are seated correctly in the drop outs.

    A picture of your setup may also be useful for this thread

  7. #7
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    Thanks for the helpful tips everyone. I don't have any pics to post, since my digital camera is currently out of town. However, it sounds like axle placement is the problem. I adjust the setup with the bike upright. Looking at the wheel from the drive side of the bike, the axle is ~ 5 o'clock relative to the bolts. Seems that I should add a link to the chain and try and get it set up about 90 degrees or so further back. I don't really want to remove the paint from my steel dropouts, but I could try roughing it up a bit to ensure the bolts are grabbing tightly. Dropouts are clean and not chipped.

    Hopefully this'll sort it out. At 135 lbs, I doubt I'm putting any sort of unusually high torque on my drivetrain as I crank up hills, so I was a little shocked to see this slipping.

  8. #8
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    So instead of working it's way loose, you have to set up the hub so your body weight and rotational force pulls on the chain? Which then tensions the chain like the guitar string, which in turn pulls on your chainring, which pulls on your bb, then frame. Sounds like a potentially bad situation with lots of binding, resistance, and premature wear. I used to have an ENO and had it set up in the 5:00 position. It never worked it's way loose but if it did, it would release tension on the chain rather than pull harder and harder. Seriously, I think you need to figure out a way to keep it from slipping rather than using your entire body weight to tension the chain.

  9. #9
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    Yeah guys, don't position the axle to make the chain tighter. If it's slipping its slipping, PERIOD, and all you're going to do is bind the chain by putting too much tension on it causing premature chain/cog/chainring wear and a potential broken chain. Now go and REMOVE the paint (down to clean metal) on both sides of the dropout where the axle and bolt contact it to PREVENT slipping, (not change the direction of it). I rode an ENO for about 4 years and weigh a little over 200. Not one sign of slipping.

  10. #10
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    Quote Originally Posted by Treybiker
    Yeah guys, don't position the axle to make the chain tighter. If it's slipping its slipping, PERIOD, and all you're going to do is bind the chain by putting too much tension on it causing premature chain/cog/chainring wear and a potential broken chain. Now go and REMOVE the paint (down to clean metal) on both sides of the dropout where the axle and bolt contact it to PREVENT slipping, (not change the direction of it). I rode an ENO for about 4 years and weigh a little over 200. Not one sign of slipping.
    Hmmm. This also makes good sense. I hadn't thought this through completely in terms of the increased stress on the chain in the other position, if it continues to slip...

    Still not clear how to prevent my steel dropouts from rusting if I strip the paint away... Unless those are typically made from stainless and welded onto the regular chromoly... Any thoughts on this before I go mad with the paint remover and sandpaper? Maybe I'll post up in the Rocky mountain forum and see if anyone knows what dropouts were being used in '97.

  11. #11
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    Quote Originally Posted by EvilScience
    Hmmm. This also makes good sense. I hadn't thought this through completely in terms of the increased stress on the chain in the other position, if it continues to slip...

    Still not clear how to prevent my steel dropouts from rusting if I strip the paint away... Unless those are typically made from stainless and welded onto the regular chromoly... Any thoughts on this before I go mad with the paint remover and sandpaper? Maybe I'll post up in the Rocky mountain forum and see if anyone knows what dropouts were being used in '97.
    It's not stainless, but it will rust little if at all. My steel 1991 frame hasn't, and it always had the paint taken off the dropouts. I wrenched 12+ years in shops, and I did this to all my bikes. Paint is soft and slippery thus not making for a good solid contact point.

  12. #12
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    Quote Originally Posted by sperryjed View Post
    pop. The Joker does make his first appearance in the second episode, "Christmas with The Joker." This episode introduces not only The Joker, played always and marvelously by Mark Hamill, but also the character of Dick Grayson, aka Robin the Boy Wonder...
    You're so stupid, spambot, this thread is over 4 years old. The joke is on you.

  13. #13
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    Quote Originally Posted by fit24hrs View Post
    So instead of working it's way loose, you have to set up the hub so your body weight and rotational force pulls on the chain? Which then tensions the chain like the guitar string, which in turn pulls on your chainring, which pulls on your bb, then frame. Sounds like a potentially bad situation with lots of binding, resistance, and premature wear. I used to have an ENO and had it set up in the 5:00 position. It never worked it's way loose but if it did, it would release tension on the chain rather than pull harder and harder. Seriously, I think you need to figure out a way to keep it from slipping rather than using your entire body weight to tension the chain.
    LOL. Absurd.

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