Bottom Brackets

Discussion in 'Cycling Archive' started by Tosspot, Feb 5, 2014.

  1. Tosspot

    Tosspot Guest

    Right, I've had enough of replacing Shimano Hollowtech II bottom
    brackets every year. The time has come for a proper sealed unit that
    will handle all year around commuting.

    The BB width is 68mm[1]. Any suggestions?

    [1] http://www.cotic.co.uk/product/roadrat
     
    Tosspot, Feb 5, 2014
    #1
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  2. Tosspot

    Rob Morley Guest

    The Chris King external bottom bracket comes with a five year guarantee
    (as long as you use their grease injector tool to lube it regularly).
     
    Rob Morley, Feb 5, 2014
    #2
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  3. Tosspot

    Tosspot Guest

    Double that and I'd be more interested, although I could keep the cranks.


    Blimey, not cheap are they!

    http://www.wiggle.co.uk/chris-king-bottom-bracket-cup-set/
     
    Tosspot, Feb 5, 2014
    #3
  4. Tosspot

    Rob Morley Guest

    That sort of made in the USA quality doesn't come cheap, although I'm
    not convinced that their prices are altogether justified.
     
    Rob Morley, Feb 5, 2014
    #4
  5. Tosspot

    Ian Smith Guest

    Glad I'm not the only one. Actually thought I might be either not
    installing it right somehow, or not pedalling in a manner beneficial to
    bottom bracket longevity. So it's the part itself lacking robustness.
     
    Ian Smith, Feb 5, 2014
    #5
  6. Tosspot

    Rob Morley Guest

    I suspect it's mainly that they're supposedly "greased for life" - I
    used to regrease cheap FAG bottom brackets and they lasted ages.
     
    Rob Morley, Feb 5, 2014
    #6
  7. I've got an ordinary Shimano UN53 (ish) sealed unit on the audax bike, and
    another on the Triumph, and they've both been on there for... well, enough
    years I couldn't tell you when I replaced them last.
     
    David Damerell, Feb 6, 2014
    #7
  8. Tosspot

    Tosspot Guest

    Nah, reading around 2-3000 miles seems to be normal, subtract from that
    if you ride in really shitty conditions. Winter salt and grit seems to
    be the killer.

    I'm really pissed, because going hub gear was a "I won't have to worry
    about chains and sprockets any more", got suckered into marketing
    bollix, and now, no, I don't replace my chain/casette every year, I
    change my bottom bracket, which is a worse job than the annual chain change.
     
    Tosspot, Feb 6, 2014
    #8
  9. Tosspot

    Tosspot Guest

    Perzackerly, and that is how it *should* be!


    The UN53/54/55 units seem to be very good VFM. But I'm not averse to a
    bit of willy waving, but likely not Chris King :-(
     
    Tosspot, Feb 6, 2014
    #9
  10. Tosspot

    soup Guest

    Is that some sort of euphemism. :O)
     
    soup, Feb 6, 2014
    #10
  11. Tosspot

    Rob Morley Guest

    Are you perhaps tightening the chain a bit too much? That would
    explain bearings not lasting. Do you have an effective front
    mudguard? Because chucking salt water at the bottom bracket will also
    shorten its life considerably.
     
    Rob Morley, Feb 6, 2014
    #11
  12. Tosspot

    Tosspot Guest

    A cm or so vertical movement on a the tight spot.

    Yes, mudguard plus flappy spray thing, but it still hit the BB area.
    I'd need a mudguard down to the ground to stop that.
     
    Tosspot, Feb 6, 2014
    #12
  13. Tosspot

    Tosspot Guest

    Look ma! Chris King bottom bracket. Have you *any* idea how much that
    costs...
     
    Tosspot, Feb 6, 2014
    #13
  14. Tosspot

    Danny Colyer Guest

    Nah, what you really need is a recumbent :D
     
    Danny Colyer, Feb 6, 2014
    #14
  15. Tosspot

    Clive George Guest

    The SMGT is good in deep puddles isn't it.
     
    Clive George, Feb 6, 2014
    #15
  16. In uk.rec.cycling.moderated on Thu, 06 Feb 2014 22:23:32 +0000
    So is the Giro.

    Was on a ride with some people the other day and came to the Tempe
    underpass. Which does flood a bit at high tide but usually only about
    8-10" max.

    That day it was damn near up to the Giro's seat height! So that's
    standard car seat height.

    The bod in the velo declined to drown and drafted help to carry his
    velo up the stairs...

    Zebee
     
    Zebee Johnstone, Feb 7, 2014
    #16
  17. Tosspot

    kimble Guest

    Until you have to clean it...

    Was out for a ride a couple of weeks ago which included some stretches
    of flooded road. As I watched my upwrongular companions getting their
    feet wet, my main thought was "good thing I didn't bring the ICE trike".


    Kim.
    --
     
    kimble, Feb 7, 2014
    #17
  18. Tosspot

    Scion Guest

    Tosspot put finger to keyboard:
    Or a baffle just in front of the bottom bracket?
     
    Scion, Feb 7, 2014
    #18
  19. Tosspot

    Tosspot Guest

    On 07/02/14 17:27, Scion wrote:

    Granted. But why not just get a BB that works instead of reverse
    engineering it from one that doesn't?

    I'm sure they have their place on downhill bikes that do a couple of
    hundred miles a year, but 2K a year in all weathers, even my old
    cup'n'cone BB from my Carlton Criterium lasted longer than that.


    Oh my Dog! Same colour! Same lights! Look at those mudguards!

    http://www.retrobike.co.uk/forum/viewtopic.php?t=111266

    Fucking hell, I'm 12 years old again!!!

    I wonder if those rims are proper chromed steel...they are! <swoons>
     
    Tosspot, Feb 7, 2014
    #19
  20. Tosspot

    Rob Morley Guest

    I was going to suggest the same, a Crud Catcher variant, but it's not
    obvious what the best size and position would be. If it sits on the
    bottom of the down tube it has to fit between the cranks, so hardly
    provides any extra cover (although it might be worthwhile to cover the
    chainrings too) while if you make it big enough to really shield the
    area it has to sit nearly as far forward as the mudguard. It could be
    that just adding a lip to the edge of the bottom bracket shell will
    direct a significant amount of water under/behind the axle, but I
    suspect that most of it already just drips off the bottom anyway,
    rather than finding its way around to the seals. Who has a 3D printer
    and some time to spare? :)
     
    Rob Morley, Feb 7, 2014
    #20
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