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  1. #1
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    NOOB questions

    Being a lazy, good4little slacker, I had the local Ace mechanic convert my old bike to a single speed using a White Brothers Eno, a Shimano 1 speed freewheel and the existing XT crankset with 32 tooth middle ring. I honestly didn't know if I was going to like SS because I'm clicking through those gears all time. As I turns out, I'm digging the one speed. Now, it's time to figure out what's going on.

    The first thing I noticed is that the Shimano ChainRing is not perfectly round. It's not exactly biopace, but it is causing chain tension issues. In the interest of sparing my knees anymore blood letting, I want to get a ChainRing that is as round as possible. I think the XT is 104 BCD, so the option seems plentiful.

    I'm currently running a 32 x 16 (3.9 inches/nominal), but I need more to have a collection of gears both higher and lower. It seems like 16 is as small as the Shimano 1 speed freewheel gets. I'm not married to the Shimano, but it seems like it would be best to stick with one brand to avoid having to mess with the chainline when switching cogs.

    Given all this, I'm thinking about a 34 tooth chainring and adding a 17 and 18 tooth Shimano 1 speed freewheel. Of course, I'll be replacing the chain. What size should I get 3/32 or 1/8th?

    Reliability is the key (as I mentioned, I'm a slacker and don't want to fuss with the parts all day), but I do plan to race on this 26 inch, hardtail bike ...so I don't want to put a bunch of heavy junk on there either.

    Any comments on my plan are greatly appreciated.

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    yea, a round chainring and cog is key. You also dont want to use gears from a geared bike as they are ramped for shifting, and you definitely dont want it to shift on you. Definitely get something SS specific. Since you're running a freewheel, you may want to look at the White Industries products that you can get from our very own Ernesto_from_wisconsin. They seem to be one of the best from what i hear. They are well sealed and rebuildable, which is key for mountainbiking. a regular bmx freewheel probably wont go the distance. If you cant go any smaller on the cog, you can always swap out your chainrings instead. So instead of having 3 different freewheels, just get one good one and have 3 different chainrings. So i'd buy a good reliable freewheel that will be easy enough with a 32t chainring on the front, and buy a few larger chainrings to throw on when you need something a little different.
    As for the chain, honestly a good 8 speed chain is all you need. Those are 3/32".
    Personally i switch between a 32-17 and a 32-18 because of our excessively long and steep hills around here. If you live in a flatter region, you may want to go a little harder.

  3. #3
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    Quote Originally Posted by GlazedHam
    Being a lazy, good4little slacker, I had the local Ace mechanic convert my old bike to a single speed using a White Brothers Eno, a Shimano 1 speed freewheel and the existing XT crankset with 32 tooth middle ring. I honestly didn't know if I was going to like SS because I'm clicking through those gears all time. As I turns out, I'm digging the one speed. Now, it's time to figure out what's going on.

    The first thing I noticed is that the Shimano ChainRing is not perfectly round. It's not exactly biopace, but it is causing chain tension issues. In the interest of sparing my knees anymore blood letting, I want to get a ChainRing that is as round as possible. I think the XT is 104 BCD, so the option seems plentiful.

    I'm currently running a 32 x 16 (3.9 inches/nominal), but I need more to have a collection of gears both higher and lower. It seems like 16 is as small as the Shimano 1 speed freewheel gets. I'm not married to the Shimano, but it seems like it would be best to stick with one brand to avoid having to mess with the chainline when switching cogs.

    Given all this, I'm thinking about a 34 tooth chainring and adding a 17 and 18 tooth Shimano 1 speed freewheel. Of course, I'll be replacing the chain. What size should I get 3/32 or 1/8th?

    Reliability is the key (as I mentioned, I'm a slacker and don't want to fuss with the parts all day), but I do plan to race on this 26 inch, hardtail bike ...so I don't want to put a bunch of heavy junk on there either.

    Any comments on my plan are greatly appreciated.
    there is no such thing as a round chainring. all of mine are out of round a little bit. the best thing to do is find the peak in the chainring and freewheel and flip them, have them peak opposite eachother. it works for me at least.
    Ride & Smile

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    Quote Originally Posted by Mighty Matt
    there is no such thing as a round chainring.
    Not true!
    But there are more variables than just the chainring, like inconsistant chain stretch and as you mentioned, the freewheel.

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    Quote Originally Posted by Mighty Matt
    there is no such thing as a round chainring. all of mine are out of round a little bit. the best thing to do is find the peak in the chainring and freewheel and flip them, have them peak opposite eachother. it works for me at least.
    Wouldnt that only help if front and rear are the same number of teeth?

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    Quote Originally Posted by Brandon_oma#692
    Wouldnt that only help if front and rear are the same number of teeth?
    wait, not everyone runs a 32-32?

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    Quote Originally Posted by ISuckAtRiding
    wait, not everyone runs a 32-32?
    11-11 - it's waaay lighter
    Honestly... ahh I give up

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    Quote Originally Posted by ISuckAtRiding
    yea, a round chainring and cog is key. You also dont want to use gears from a geared bike as they are ramped for shifting, and you definitely dont want it to shift on you. Definitely get something SS specific. Since you're running a freewheel, you may want to look at the White Industries products that you can get from our very own Ernesto_from_wisconsin. They seem to be one of the best from what i hear. They are well sealed and rebuildable, which is key for mountainbiking. a regular bmx freewheel probably wont go the distance. If you cant go any smaller on the cog, you can always swap out your chainrings instead. So instead of having 3 different freewheels, just get one good one and have 3 different chainrings. So i'd buy a good reliable freewheel that will be easy enough with a 32t chainring on the front, and buy a few larger chainrings to throw on when you need something a little different.
    As for the chain, honestly a good 8 speed chain is all you need. Those are 3/32".
    Personally i switch between a 32-17 and a 32-18 because of our excessively long and steep hills around here. If you live in a flatter region, you may want to go a little harder.

    Thanks for the response. The Eno's are about 4X the cost of the Shimano, but only 1/1000 the cost of replacing a knee cap. I can easily talk myself into buying one, but two is going to be a little tougher.

    Does anyone know if the White Industries Dos FreeWheel (has two cogs) is legal for racing in the single speed category?

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    Quote Originally Posted by GlazedHam
    Thanks for the response. The Eno's are about 4X the cost of the Shimano, but only 1/1000 the cost of replacing a knee cap. I can easily talk myself into buying one, but two is going to be a little tougher.

    Does anyone know if the White Industries Dos FreeWheel (has two cogs) is legal for racing in the single speed category?
    i think it should be fine unless you have the means to change gears on the fly.
    Also, make sure your chainline is good. if it's not straight, your chain will drop and/or wear out your gear prematurely.
    And like i said, you can just buy one, and buy an assortment of chainrings instead. The chainrings will be about half the cost of the freewheel.

  10. #10
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    Mine goes to 11.

    This issue comes up often enough that it needs to be added to the faq

    Sheldon Brown talks about a technique for dealing with this issue here. Basically, you loosen your chainring bolts, turn the cranks until it gets to the tight spot, then give your chain ring a little tap with a soft-face hammer to shift it a bit. lather, rinse, repeat until you get it to a happy place.

  11. #11
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    Quote Originally Posted by Brandon_oma#692
    Wouldnt that only help if front and rear are the same number of teeth?
    32/16, 34/17,... I think those would benefit also.

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    Quote Originally Posted by xls
    32/16, 34/17,... I think those would benefit also.
    then it would go extra tight every other rev
    Honestly... ahh I give up

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    You sure your chainring is on right?

    I had this problem briefly, looked at how I had installed it, and discovered that the chainring had gaps where it sits on the cranks. I had to take a credit card, loosen the bolts and stick the CC in the gaps all the way around to make sure it was sitting on the cranks evenly. I know I'm not describing this well, but if you look closely at the chainring & the tolerances, you may see uneven gaps near the bolts. Seems that my chainrings (both old and new) were a bit larger than they should have been. I put the new one on & used the CC, and it seems to be fine.
    Hogan Lake blog. A section of Hogan Lake trails here.

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    Quote Originally Posted by Finch Platte
    You sure your chainring is on right?

    I had this problem briefly, looked at how I had installed it, and discovered that the chainring had gaps where it sits on the cranks. I had to take a credit card, loosen the bolts and stick the CC in the gaps all the way around to make sure it was sitting on the cranks evenly. I know I'm not describing this well, but if you look closely at the chainring & the tolerances, you may see uneven gaps near the bolts. Seems that my chainrings (both old and new) were a bit larger than they should have been. I put the new one on & used the CC, and it seems to be fine.
    I actually run my bolt holes a little tighter on the chainrings i make so it locates closely on them. Seems to be working so far.
    If you look at alot of Shimano cranks, they only locate on the bolts.

  15. #15
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    patella tendoncies

    Quote Originally Posted by highdelll
    then it would go extra tight every other rev
    Well, at least I would keep smacking the same knee every time the chain popped off
    Last edited by GlazedHam; 03-19-2010 at 07:34 PM.

  16. #16
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    Quote Originally Posted by GlazedHam
    Well, at least I would keep smacking the same knee every time the change popped off
    good point - only one kneepad to buy!
    Honestly... ahh I give up

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