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  1. #1
    Senior Member mazdaspeed's Avatar
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    Singlespeed crew: chain tension? (noob question time)

    For those of you not familiar with the magic gear, it's basically just using gear sizes to create the proper tension on a singlespeed chain for bikes with vertical dropouts. I ended up with 18/36 which, according to the magic gear calculator deal (also based on the size of my frame and the chain), is "in the green".

    What I'm wondering about though, is that if I freewheel it backwards and pull up and over on the chain, I can get it to hook on the other side and come off the gear. I can also do this to my bikes with derailers, but I don't know if it's OK for a singlespeed.

    Should I be concerned about this? I haven't ridden the bike yet by the way, it's not done.

  2. #2
    Look at all these buttons EivlEvo's Avatar
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    Im not sure I get what ur saying. I ride fixed and ss and there's never a circumstance where I can derail my own chain by flexing the frame or cranks. Im sure it could happen if I imposed a load on it... But it never has.

    I also can't do this on my geared bikes.

  3. #3
    M_S
    M_S is offline
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    Or you could get a ceap chain tensioner, not worry about it, and even be able to choose a gear that fits the type of riding you do instead of havong to accept whatever is "in the gren."

    Just a thought.

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    Senior Member mazdaspeed's Avatar
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    Quote Originally Posted by EivlEvo View Post
    Im not sure I get what ur saying. I ride fixed and ss and there's never a circumstance where I can derail my own chain by flexing the frame or cranks. Im sure it could happen if I imposed a load on it... But it never has.

    I also can't do this on my geared bikes.
    I'm not talking about flexing the frame or cranks, I'm just trying to describe the looseness of the chain. I just don't know if it's too loose for a mountain bike.

  5. #5
    Senior Member mazdaspeed's Avatar
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    Quote Originally Posted by M_S View Post
    Or you could get a ceap chain tensioner, not worry about it, and even be able to choose a gear that fits the type of riding you do instead of havong to accept whatever is "in the gren."

    Just a thought.
    2:1 is the ratio I wanted anyway, that's not a problem. A tensioner isn't a bad idea but the point of the magic gear is to (use a 2:1 ratio) and use the right gearing (for example 32/16, 36/18, 40/20) to ensure that the chain is roughly the right tension.

    I guess what it comes down to is what will happen if the bike is shocked, how loose can the chain be without a major risk of coming off the gears?

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    I know of a guy that went with the magic gear route. I believe his chain stretched to the point of not being usable in 4 months or less. I would invest in a good tensioner, personally.

  7. #7
    Senior Member mazdaspeed's Avatar
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    Quote Originally Posted by croscoe View Post
    I know of a guy that went with the magic gear route. I believe his chain stretched to the point of not being usable in 4 months or less. I would invest in a good tensioner, personally.
    Got any suggestions on small/easy to install ones?

  8. #8
    Senior Member biknbrian's Avatar
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    Quote Originally Posted by mazdaspeed View Post
    What I'm wondering about though, is that if I freewheel it backwards and pull up and over on the chain, I can get it to hook on the other side and come off the gear. I can also do this to my bikes with derailers, but I don't know if it's OK for a singlespeed.

    Should I be concerned about this? I haven't ridden the bike yet by the way, it's not done.
    Does chain pop off when you ride it, if not then it's fine.

  9. #9
    Look at all these buttons EivlEvo's Avatar
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    Quote Originally Posted by mazdaspeed View Post
    Got any suggestions on small/easy to install ones?
    I have the one from performance bike ( i think... ,its a surly ripoff)

    It works ok... I took it off.

  10. #10
    BFG
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    Just say no to brakes. BFG's Avatar
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    Surly and DMR both make quality chain tensioners from what I've heard. Please note that's only what I've heard, not experience.

  11. #11
    is slower than you Peek the Geek's Avatar
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    Have you considered trying a "Half Link" to tighten up the chain?


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    Quote Originally Posted by Peek the Geek View Post
    Have you considered trying a "Half Link" to tighten up the chain?

    That's what I did. Worked like a charm. You will of course go through chains a bit quicker but I save them until I get a pile then I sell them to a scrap yard for a pittance.

  13. #13
    Senior Member mazdaspeed's Avatar
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    Quote Originally Posted by Peek the Geek View Post
    Have you considered trying a "Half Link" to tighten up the chain?

    That's a good idea as well

  14. #14
    Senior Member mazdaspeed's Avatar
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    Quote Originally Posted by biknbrian View Post
    Does chain pop off when you ride it, if not then it's fine.
    I guess I'll have to ride it and see. I've been sick all week and it's raining outside so I haven't felt like riding

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