eccentric bottom bracket in a standard shell?

Discussion in 'Cycling Equipment' started by Wayne, Mar 27, 2003.

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  1. Wayne

    Wayne Guest

    Are there any eccentric bottom brackets available for 68mm BB shells? Or would I be better off using
    a chain tensioner (Surly, or similar) to effect a single-speed conversion for a good steel frame
    with vertical dropouts? Thanks ..

    Wayne
     
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  2. Ted Bennett

    Ted Bennett Guest

    > Are there any eccentric bottom brackets available for 68mm BB shells? Or would I be better off
    > using a chain tensioner (Surly, or similar) to effect a single-speed conversion for a good steel
    > frame with vertical dropouts? Thanks ..
    >
    > Wayne

    Not for the standard, threaded type; there isn't enough room in there to allow the 1/2" adjustment.

    Using a chain tensioner will do the trick, but it takes away some of the visual simplicity that is
    attractive about single-speeds. It may be possible to choose sprockets that will allow proper chain
    tension without the tensioner.

    Another possibility is to use White Industries' hub with eccentric mounting, which is a fairly
    pricey solution but one that works great. See Sheldon Brown's fixed gear pages.

    A word of warning: If you meant to say fixed gear rather than single-speed, then DO NOT use a chain
    tensioner. Bad things will happen.

    --
    Ted Bennett Portland OR
     
  3. Steve

    Steve Guest

    [email protected] (Wayne) wrote in message
    news:<[email protected]>...
    > Are there any eccentric bottom brackets available for 68mm BB shells? Or would I be better off
    > using a chain tensioner (Surly, or similar) to effect a single-speed conversion for a good steel
    > frame with vertical dropouts? Thanks ..
    >
    > Wayne

    A new single speed/fixed gear rear hub came out a short while ago. It's made by White Industries I
    think. The hub itself is eccentric, with the bearings offset, elimnating the need for an eccentric
    bb or tensioners
     
  4. Mike S.

    Mike S. Guest

    "Steve" <[email protected]> wrote in message
    news:[email protected]...
    > [email protected] (Wayne) wrote in message
    news:<[email protected]>...
    > > Are there any eccentric bottom brackets available for 68mm BB shells? Or would I be better off
    > > using a chain tensioner (Surly, or similar) to effect a single-speed conversion for a good steel
    > > frame with vertical dropouts? Thanks ..
    > >
    > > Wayne
    >
    >
    > A new single speed/fixed gear rear hub came out a short while ago. It's made by White Industries I
    > think. The hub itself is eccentric, with the bearings offset, elimnating the need for an eccentric
    > bb or tensioners

    I got to thinking about the new eccentric hub. Wouldn't that mean adjusting your brakes every time
    you moved the wheel around? Seems to me that while it is a good idea, I don't particularly want to
    re-adjust my brakes every time I move the rear wheel around.

    Then again, eccentric BBs make you move the saddle around, so...

    Mike
     
  5. >>A new single speed/fixed gear rear hub came out a short while ago. It's made by White Industries I
    >>think. The hub itself is eccentric, with the bearings offset, elimnating the need for an eccentric
    >>bb or tensioners
    >
    > I got to thinking about the new eccentric hub. Wouldn't that mean adjusting your brakes every time
    > you moved the wheel around? Seems to me that while it is a good idea, I don't particularly want to
    > re-adjust my brakes every time I move the rear wheel around.

    The same can be true of horizontal-slot fork ends. If you set up with fixed/free, you don't need the
    rear brake when you're using the fixed side.

    On my Rambouillet, however, I have OK brake pad alignment with both the 15 fixed and 17 freewheel.

    See: http://sheldonbrown.com/harris/white-hubs.html

    and: http://sheldonbrown.org/rambouillet

    Sheldon "Eccentric" Brown +----------------------------------------------------+
    | War is God's way of teaching Americans geography. | -Ambrose Bierce |
    +----------------------------------------------------+ Harris Cyclery, West Newton, Massachusetts
    Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
    http://captainbike.com http://sheldonbrown.com
     
  6. Wayne

    Wayne Guest

    (multiple folks wrote variously ..)

    Thanks -- all -- for the education and alternative ideas; and yes, this was definitely a
    single-speed and not a fixed-gear question. Since disk brakes aren't of interest to me, for the
    longer term does it make more sense to consider the new White hub, or a modification to horizontal
    dropouts, do you think?

    Wayne
     
  7. Ant

    Ant Guest

    [email protected] (Wayne) wrote in message
    news:<[email protected]>...
    > (multiple folks wrote variously ..)
    >
    > Thanks -- all -- for the education and alternative ideas; and yes, this was definitely a
    > single-speed and not a fixed-gear question. Since disk brakes aren't of interest to me, for the
    > longer term does it make more sense to consider the new White hub, or a modification to horizontal
    > dropouts, do you think?
    >
    > Wayne

    if you know what gear you want to be in, and you like math, or have an lbs which will let you try
    out chainrings, then you could stick with your dropouts and have a beautiful machine without the
    clunky tensioner, in your gear, or Almost your gear, of choice. if you want to change gears from
    time to time, i woudlnt do this, unless you own a bike shop.

    if you want to change gears, either to suit your mood, or to find the one you want, then both of
    your posted options should work. ive switched my back cog on my bike between three or four sizes in
    the last few months, and ive never *had* to readjust the brakes. i did once, but it was splitting
    hairs, but then- ive been making incremental changes, not switching a 13 tooth cog for an 18.

    a horizontal (road, not track!) dropout is slanted, such that moving the wheel forwards and
    backwards in the drop (as you switch out the cogs) means that the brake pads end up fairly well
    adjusted in most cases. ymmv.

    the hub is very expensive and very elegant. i imagine you would be more likely to have to readjust
    your brakes when you change gears taking up chain slack with the hub than you would with a horz
    dropout, but then i havent done the math, and id hate to put you on the wrong track.

    all brake adjustment aside (it doesnt take that long), are you saying that you are considering
    having horizontal dropouts installed instead of your current vertical? if so, i would definitely go
    with the hub just for the fact that it would cost as much as the hub just to have your bike
    repainted, and that would be After you found someone to pull your old dropouts, braze the new ones
    in, and so on and so forth.

    singlespeed is great. fixed is better, but ss is a step in the right direction. ;)

    anthony
     
  8. Wayne

    Wayne Guest

    [email protected] (ant) wrote interesting things ..

    Thanks once more. If I understand correctly (often a dubious proposition), with the White hub the
    steps to SS would essentially be: new rear wheel with the White hub, freewheel, pick a cog; remove
    inner & outer chainrings (assuming I'm happy with the size of the middle ring); new chain; remove
    deraileurs and shifters; adjust the rear v-brake as necessary? How long has this hub been around in
    real use, does anyone here know?

    Wayne
     
  9. Wayne wrote:
    > ... with the White hub the steps to SS would essentially be: new rear wheel with the White hub,
    > freewheel, pick a cog; remove inner & outer chainrings (assuming I'm happy with the size of the
    > middle ring); new chain; remove deraileurs and shifters; adjust the rear v-brake as necessary?

    Right. You'll need a set of short stack bolts for the single chainring, because the standard bolts
    are too long.

    Also, I'd advise adding a fixed sprocket and lockring so you can flip the wheel around and use it as
    a fixed gear some of the time. Typical off-road singlespeed gearing is painfully low/slow for riding
    on pavement.

    > How long has this hub been around in real use, does anyone here know?

    They started shipping in very limited quantities near the end of January. I've been riding mine for
    less than a month, but I'm sold on it.

    http://sheldonbrown.com/harris/white-hub.html

    Sheldon "Thanks, Doug!" Brown +--------------------------------------------------------------+
    | Readers of a historical bent may be interested in my | great-grandfather's journal of life as
    | a sailor 1859-1869 | http://www.sheldonbrown.com/anders_junnila.html |
    +--------------------------------------------------------------+ Harris Cyclery, West Newton,
    Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
    shipped Worldwide http://captainbike.com http://sheldonbrown.com
     
  10. Peter

    Peter Guest

    "Wayne" <[email protected]> wrote in message
    news:[email protected]...
    > Are there any eccentric bottom brackets available for 68mm BB shells? Or would I be better off
    > using a chain tensioner (Surly, or similar)
    cut.....

    I recently fitted a Rohloff hub to vertical dropouts. In the end I decided to use a chain
    tensioner supplied by Rohloff for their hubs but one of the things I considered was using a half
    link to give the correct chain length? If this would solve the problem it seems the simplest
    solution for a SS. retep
     
  11. Bluto

    Bluto Guest

    [email protected] (Wayne) wrote:

    > Thanks once more. If I understand correctly (often a dubious proposition), with the White hub the
    > steps to SS would essentially be: new rear wheel with the White hub, freewheel, pick a cog; remove
    > inner & outer chainrings (assuming I'm happy with the size of the middle ring); new chain; remove
    > deraileurs and shifters; adjust the rear v-brake as necessary?

    To give you yet another, cheaper approach to your issue, check this link:

    http://www.peak.org/~fixin/fixmeup.html

    It's by the guy who persuaded White Industries to make their eccentric hub. He offers eccentric
    axles for sealed bearing hubs and , more significantly, a Java applet that will calculate what
    sprocket/cog combos will work with your vertical-dropout frame. The site is a good resource for what
    you are doing.

    Chalo Colina
     
  12. Someone posted:

    > I recently fitted a Rohloff hub to vertical dropouts. In the end I decided to use a chain
    > tensioner supplied by Rohloff for their hubs but one of the things I considered was using a half
    > link to give the correct chain length? If this would solve the problem it seems the simplest
    > solution for a SS.

    Yes, this is one of many kluges that sometimes works. I have more detail on this issue at:

    http://sheldonbrown.com/fixed-conversion.html#vertical

    However, the White Industries hub is by far the nicest solution.

    Sheldon "Half Links And Files No Longer Needed" Brown +-------------------------------------------+
    | Any smoothly functioning technology | will have the appearance of magic. | --Arthur C. Clarke |
    +-------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
    617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
    http://captainbike.com http://sheldonbrown.com
     
  13. Wayne

    Wayne Guest

    Sheldon Brown <[email protected]> (and others) wrote helpfully ..

    Ok. I understand, I think; thank you all. For the time being the easiest first step seems to me to
    be a Singleator or the Paul's device, with a more permanent solution (White's ENO SS hub, reworked
    dropouts ..) saved for a bit later. (What do you do anyway with the derailleur hanger when
    converting a vertical-dropout frame to SS with the White's hub?)

    Your point concerning fixed vs. ss in terms of gearing is interesting. Is there, somewhere, a
    recommended set of approximate gearing ranges -- as gain ratios, even! -- for use in non-competitive
    bicycling for the terrain type most often encountered by a particular rider? E.g., flat-ish, mildly
    rolling, rolling, real hills, mountains? Clearly needing to spin at 130+ just to get anywhere on a
    flat road could become .. tiring, just as would having a too-big gear up a nasty hill.

    Wayne
     
  14. Ant

    Ant Guest

    [email protected] (Wayne) wrote in message
    >
    > Ok. I understand, I think; thank you all. For the time being the easiest first step seems to me to
    > be a Singleator or the Paul's device, with a more permanent solution (White's ENO SS hub, reworked
    > dropouts ..) saved for a bit later. (What do you do anyway with the derailleur hanger when
    > converting a vertical-dropout frame to SS with the White's hub?)

    its one or the other- hub or horizontal drops. certainly not both. ever built a wheel? the surly
    tensioner is not that cheap, IIRC. how bad would it be to buy the hub now and rebuild your wheel
    with it? spokes you can get for less than 20 bucks a wheel, and the hub is as expensive as it will
    be when you get around to buying it, most likely. wheel building is not hard, just requires
    patience, imho. if it is not something youve done before, sheldon's site has solid instructions.

    honestly, i think youd be crazy to consider reworking your dropouts. are you still considering this?
    i waxed long about the advantages of them, but its a lot of trouble to actually switch. if you
    desperately wanted horizontal dropouts, it would be cheaper probably to buy a new steel frame with
    them instead of refitting your own frame. the hub solves everything if you can spare the change, and
    a dropout switch would cost far far more than a hub and a few spokes (or even a new wheel)

    the only reason i can think of to even entertain the idea of switching to h.drops is the fact that
    brakes dont need (much) realignment when changing gears. so if you want to switch gears frequently,
    either re-evaluate your ss goals, or go with sheldon's advice-

    if you use a fixed gear as your fast gear, it doesnt matter if the rear brake pads dont line up with
    the rim. you can brake powerfully with your legs, and wont likely need to anyway, and you can just
    leave the brake quick release off until you switch back to your ss gear.

    > Your point concerning fixed vs. ss in terms of gearing is interesting. Is there, somewhere, a
    > recommended set of approximate gearing ranges -- as gain ratios, even! -- for use in
    > non-competitive bicycling for the terrain type most often encountered by a particular rider?
    > E.g., flat-ish, mildly rolling, rolling, real hills, mountains? Clearly needing to spin at 130+
    > just to get anywhere on a flat road could become .. tiring, just as would having a too-big gear
    > up a nasty hill.

    your bike has gears now, yes? take it for a spin and try the gears out. you should be able to get
    darn close to your SS gear of choice by leaving the bike in one gear and seeing what works. maybe
    you could start with the gear you spend the most time in, and dial it up or down to suit the needs
    of the total ride (like try lower if you have a huge hill to get up on the way to the trails, or
    higher if there is a big downhill you want to fly through, etc)
     
  15. Wayne

    Wayne Guest

    [email protected] (ant) wrote in message
    news:<[email protected]>...
    > your bike has gears now, yes? take it for a spin and try the gears out. you should be able to get
    > darn close to your SS gear of choice by leaving the bike in one gear and seeing what works ..

    A sensible and obvious-in-retrospect plan; an embarrassed thank-you.

    Wayne
     
  16. Wayne

    Wayne Guest

    Sheldon Brown <[email protected]> wrote:
    > .. They started shipping in very limited quantities near the end of January. I've been riding mine
    > for less than a month, but I'm sold on it.
    >

    One LAST question on this, please: your website indicates that the bike's rear end will be slightly
    raised, and some frame/brake combinations won't work. Pls characterize "slightly" here (I'm unclear
    on the mechanics of an eccentric hub, or BB)? And I imagine that so long as my current v-brake setup
    has nearly a cm. of wiggle-room up and down to reach the rim I should be ok?

    Thanks again.

    Wayne
     
  17. Wayne wrote:
    > Sheldon Brown <[email protected]> wrote:
    >
    >>.. They started shipping in very limited quantities near the end of January. I've been riding mine
    >>for less than a month, but I'm sold on it.
    >>
    >
    >
    > One LAST question on this, please: your website indicates that the bike's rear end will be
    > slightly raised, and some frame/brake combinations won't work. Pls characterize "slightly" here
    > (I'm unclear on the mechanics of an eccentric hub, or BB)? And I imagine that so long as my
    > current v-brake setup has nearly a cm. of wiggle-room up and down to reach the rim I should be ok?

    Actually, it can be either raised or lowered, your choice. Mine lowers the rear end as I've set it
    up on the Rambouillet, but that frame has plenty of clearance.

    The amount it will be raised or lowered depends on the orientation of the hub needed to work with
    your chain-length/sprocket sizes, it can be anywhere between plus and minus 7.5 mm.

    Sheldon "This Is A GREAT Product!" Brown http://sheldonbrown.com/harris/white-hubs.html
    +----------------------------------------+
    | The race is not always to the swift, | nor the battle to the strong | -but that's the way to bet.
    | | --Damon Runyon |
    +----------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
    617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
    http://captainbike.com http://sheldonbrown.com
     
  18. x

    x Guest

    RE/
    >Are there any eccentric bottom brackets available for 68mm BB shells?

    One downside I've found with the eccentric BB route is that whatever adjustment is done via the BB
    eats into that inch or so of fore-aft saddle adjustment.
    -----------------------
    PeteCresswell
     
  19. Ant

    Ant Guest

    [email protected] (Wayne) wrote in message

    > One LAST question on this, please: your website indicates that the bike's rear end will be
    > slightly raised, and some frame/brake combinations won't work. Pls characterize "slightly" here
    > (I'm unclear on the mechanics of an eccentric hub, or BB)?

    by my very rough calculations, for a bike with wheelbase apx 1000mm, a change in rear axle height of
    5 mm results in a paltry change of .3 degrees in geometry. this, i imagine, would have an almost
    negligible effect on handling, little or no more i imagine than having different tires on
    front/rear. i imagine that if you were splitting hairs, you could tilt the saddle up a hair, but the
    real issue sounds like the brakes working out alright, and if you are currently in the middle of
    your v-brake adjustment range, and you will use the same rims, then it sounds quite doable. but
    then- ive never actually used one of these hubs.

    siiiigh.. one day..
     
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