Shimano Hollowtech II Bottom Bracket Cup Diameters

2plus2
2plus2 Posts: 53
edited August 2017 in Workshop
I'm having a little trouble understanding the sizing in terms of diameter of Shimano bottom brackets. I've swapped out my Sram Apex chainset for Shimano 105 and so I'm swapping the BB at the same time. I used the Park BBT-9 to remove the Sram BB (the same tool which also works on a Shimano BB-RS500 BB I have on another bike). I expected to be able to fit the new SM-BBR60 using this as well, but the diameter of the BB is smaller so the tool doesn't even touch the sides.

Wondering what the deal is with BB diameters, are they available in 2 options and I've just picked the wrong one? Or as you move up the Shimano range does the size go down? Need to pick up a new tool or new BB either way, just need to decide which.

Comments

  • Man Of Lard
    Man Of Lard Posts: 903
    There are more than two diameters - as you've found there's the "standard" (Tiagra/105 are generally standard) and then there are the Ultegra/Duraace (which are different).

    Usually (at least every one I've bought) the Ultegra BB comes with an adaptor ring to bridge between the standard & the yet-another-size BB you have in your hand.... If not then you need the tool to fit (memory is telling me it's Shimano tool TLFC37 but my memory is fallible)l
  • 2plus2
    2plus2 Posts: 53
    Thanks, from a bit more searching I think it's the TL-FC24 I'm looking for. At least it's cheap, but it's still really annoying that a single company can't even standardise the tool required between their own components!
  • Man Of Lard
    Man Of Lard Posts: 903
    That's the adaptor that usually comes "free" - be aware that it doesn't fit every standard hollowtech tool (obviously should fit the real Shimano one though)
  • dannbodge
    dannbodge Posts: 1,152
    Man Of Lard wrote:
    That's the adaptor that usually comes "free" - be aware that it doesn't fit every standard hollowtech tool (obviously should fit the real Shimano one though)

    This.
    When I did my bb the adaptor wouldn't fit a borrowed tool that came from halfords, it does fit the x tools one from wiggle or the park tools one though.
  • 2plus2
    2plus2 Posts: 53
    Ahh, I obviously didn't get the free adapter...I did get a pretty good deal on the BB though so that kind of figures.
  • wolfsbane2k
    wolfsbane2k Posts: 3,056
    2plus2 wrote:
    Ahh, I obviously didn't get the free adapter...I did get a pretty good deal on the BB though so that kind of figures.

    I've got a whole bunch of spare adaptors as I bulk bought 5 BBs when they were less than a tenner a few months ago, and I get through them "quickly".. Could possibly post one if your need it, or if your in Portsmouth area....
    Intent on Cycling Commuting on a budget, but keep on breaking/crashing/finding nice stuff to buy.
    Bike 1 (Broken) - Bike 2(Borked) - Bike 3(broken spokes) - Bike 4( Needs Work) - Bike 5 (in bits) - Bike 6* ...
  • 2plus2
    2plus2 Posts: 53
    Wolfsbane2k wrote:
    2plus2 wrote:
    Ahh, I obviously didn't get the free adapter...I did get a pretty good deal on the BB though so that kind of figures.

    I've got a whole bunch of spare adaptors as I bulk bought 5 BBs when they were less than a tenner a few months ago, and I get through them "quickly".. Could possibly post one if your need it, or if your in Portsmouth area....

    Thanks for the offer, that's really good of you. I'd already ordered one along with some other bits and pieces, so I think I'm set now. Cheers.

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